3800 car chugging bad, need some help

[imported_PaceCarBoozer]

OK, so I'm driving a '94 Buick Lesabre right now and worked on it yesterday, but it drove fine all yesterday. then today it is chugging really bad at low RPM (no tach, so not sure exact). I did the plugs yesterday and it ran great, however there was alot of grease around the plugs which I cleaned as much as I could before reinstalling the new Delco plugs. I couldn't see the wires going bad, only two years old. I get an SES code coming up, but that has always come on and off (don't know the code). I am considering maybe a clogged fuel filter cause the car has sat for about 8 months without moving except for this last week. Could a misfire occur without the 'puter spitting a SES? Anyways, any ideas would be helpfull. Oh, it's a 3800 series 1 with 175,xxx on it. It was supposed to say "Dont PULL the wire with the motor running" in the topic box, it gives ya a BIG shock.
TIA
CJ

Click to read more...

 

[Turbocharged400sbc]

OK, so I'm driving a '94 Buick Lesabre right now....... Could a misfire occur without the 'puter spitting a SES? Anyways, any ideas would be helpfull. Oh, it's a 3800 series 1 with 175,xxx on it. [/b]

ahhh the good old tall deck 3800... OBD I systems cannot distinguish a missfire...you may get a lean o2 code or something similar but not always, a clogged filter always rears it's head under high load/rpm conditions, not typically at low rpm, a fuel pump will cause sputtering/chugging but i doubt thats the problem since you seem to not have any higher rpm issues.

i would start with your wires, after 2 years of thermal cycling and recently being removed it's more than possible that you broke one of the conductors, which is fairly easy even if you are carefull (i have two spare sets for my nova since i read the plugs alot at the track)

It was supposed to say "Dont PULL the wire with the motor running" in the topic box, it gives ya a BIG shock.
TIA
CJ
[/b]

uh yeah...that'll wake ya up in the morning
a tip for ya....grab 6, 3/4 inch long pieces of vacum hose (~3/16ths ID) pull the coil side wires (one at a time) and slip the hose over the terminal and set the wire back down on the hose, the carbon in the hose conducts the spark to the plug very well, and then you can cancel each cylinder by grounding the spark at the terminal (i use my testlight, but have used aluminum foil as a last resort-dont ask) and listening for a change in engine rpm/sound.

that should help you find your problem, without any shocking side effects :lolsign:

 

[imported_PaceCarBoozer]

<div class='quotemain'>
OK, so I'm driving a '94 Buick Lesabre right now....... Could a misfire occur without the 'puter spitting a SES? Anyways, any ideas would be helpfull. Oh, it's a 3800 series 1 with 175,xxx on it. [/b]

ahhh the good old tall deck 3800... OBD I systems cannot distinguish a missfire...you may get a lean o2 code or something similar but not always, a clogged filter always rears it's head under high load/rpm conditions, not typically at low rpm, a fuel pump will cause sputtering/chugging but i doubt thats the problem since you seem to not have any higher rpm issues.

i would start with your wires, after 2 years of thermal cycling and recently being removed it's more than possible that you broke one of the conductors, which is fairly easy even if you are carefull (i have two spare sets for my nova since i read the plugs alot at the track)

It was supposed to say "Dont PULL the wire with the motor running" in the topic box, it gives ya a BIG shock.
TIA
CJ
[/b]

uh yeah...that'll wake ya up in the morning
a tip for ya....grab 6, 3/4 inch long pieces of vacum hose (~3/16ths ID) pull the coil side wires (one at a time) and slip the hose over the terminal and set the wire back down on the hose, the carbon in the hose conducts the spark to the plug very well, and then you can cancel each cylinder by grounding the spark at the terminal (i use my testlight, but have used aluminum foil as a last resort-dont ask) and listening for a change in engine rpm/sound.

that should help you find your problem, without any shocking side effects :lolsign:
[/b][/quote]

Thanks, I stopped and got some wires on the way home from work, it appears that the wires are 6 years old , I didn't keep track of the maintenence on his car, but now that it's mine, I have to fix all the crap he neglected.
One oddity though, it's a '94, but has the OBD II plug which neither murray's or Autozone's computer can comunicate with, could just be a bad DIC plug, but I want to know what the code is. I got a new fuel filter too, cause who know's when that was changed (if ever) just in case. Well, time to get dirty, thanks for the input.
CJ

 

[CoolGTX]

check the obd fuse.

 

[imported_PaceCarBoozer]

check the obd fuse.
[/b]

I'm about to check all of them, got the wires in, fuel filter in (new personal record of 4 min.), but I'm wondering now if I fucked up a wire under the dash, had the bottom off replacing the turn signal flasher. Why can't cars ever break on a nice day, it always has to be cold or rainy, or something. Ok, I'm done bitching, back to work.
CJ

 

[Toasty]

your 94 is probably a obd1 car with obd2 port... or in otherwords a hybrid....

 

[imported_PaceCarBoozer]

your 94 is probably a obd1 car with obd2 port... or in otherwords a hybrid....
[/b]

sooooooo, does that mean I have to find an OBD 1 scanner with a OBD2 plug? I thought it was kind of weird, cause I was under the impression that OBDII started in '95. I hate this car.....for now.
CJ

 

[SaturdaysGS]

Its called OBD 1.5 IIRC. Hybrid anything FTL.

 

[imported_PaceCarBoozer]

so who could I take this to, to get the code checked?? I even swapped coils from my GP since I know they were working, but didn't swap the ignition module since I wasn't sure if it would work on the Buick. All the fuses are good, no cut wires I can find. Could a bad O2 cause these types of issues? Possibly a bad injector? It has to be something that just goes, not gradually, just...goes. It was driving better than ever the other day, then this morning, just crap. I appreciate all the input from everyone, anything pops in your head, just spit it out, I'm running out of ideas here.
CJ

 

[Toasty]

so who could I take this to, to get the code checked?? I even swapped coils from my GP since I know they were working, but didn't swap the ignition module since I wasn't sure if it would work on the Buick. All the fuses are good, no cut wires I can find. Could a bad O2 cause these types of issues? Possibly a bad injector? It has to be something that just goes, not gradually, just...goes. It was driving better than ever the other day, then this morning, just crap. I appreciate all the input from everyone, anything pops in your head, just spit it out, I'm running out of ideas here.
CJ
[/b]

how much gas is in it?

 

[imported_PaceCarBoozer]

<div class='quotemain'>
so who could I take this to, to get the code checked?? I even swapped coils from my GP since I know they were working, but didn't swap the ignition module since I wasn't sure if it would work on the Buick. All the fuses are good, no cut wires I can find. Could a bad O2 cause these types of issues? Possibly a bad injector? It has to be something that just goes, not gradually, just...goes. It was driving better than ever the other day, then this morning, just crap. I appreciate all the input from everyone, anything pops in your head, just spit it out, I'm running out of ideas here.
CJ
[/b]

how much gas is in it?
[/b][/quote]

just a couple gallons now, I want to do a fuel pressure check before I fill it up in case it's the pump and have to drop the tank. It should be sitting around 41-47lbs on the prime, so if I can get my hands on a tester, that will be next. Also I'm gonna start hosing the vaccum lines down with starting fluid to check for leaks. I'm just hoping it's not a intake or head gasket or something like that, I really don't have time to start tearing the motor apart.
CJ

 

[Toasty]

spray some starting fluid in the intake, too.

i was more insinuating bad/old gas rather than not enough though.

 

[imported_PaceCarBoozer]

spray some starting fluid in the intake, too.

i was more insinuating bad/old gas rather than not enough though.
[/b]

I haven't started with the starting fluid just yet, but I rented Murray's scan tool and it actually reads the car, I have a misfire in CYL 4, it has a brand new plug, new wire, and my MSD coils which were working on my GP. So, I'm looking at a new injector, correct? I can noid light it just in case to check for a pulse, but if it was having electrical problems, it would affect more than one cylinder, so should I just get a new injector for it, or should I look at something else. Also, my O2's jump from like 80 to 900, back and forth, is that "normal". I really suck at electronics and the computer controlled crap on these car, so when I see these readout, I'm not really sure what is good and what is bad.
Thanks
CJ

 

[Toasty]

<div class='quotemain'>
spray some starting fluid in the intake, too.

i was more insinuating bad/old gas rather than not enough though.
[/b]

I haven't started with the starting fluid just yet, but I rented Murray's scan tool and it actually reads the car, I have a misfire in CYL 4, it has a brand new plug, new wire, and my MSD coils which were working on my GP. So, I'm looking at a new injector, correct? I can noid light it just in case to check for a pulse, but if it was having electrical problems, it would affect more than one cylinder, so should I just get a new injector for it, or should I look at something else. Also, my O2's jump from like 80 to 900, back and forth, is that "normal". I really suck at electronics and the computer controlled crap on these car, so when I see these readout, I'm not really sure what is good and what is bad.
Thanks
CJ
[/b][/quote]

start the car, let it run just a minute or less. pull plug #4... is it covered in fuel? if it is, then your injector isnt the issue. it would then point to the igniton module... that or you cracked the porcelain on the new plug... swap the plug and wire with the cylinder next to it and see what the computer code gives. if the misfire follows the plug and wire, then you know it's not the ignition module.

 

[imported_PaceCarBoozer]

<div class='quotemain'>
<div class='quotemain'>
spray some starting fluid in the intake, too.

i was more insinuating bad/old gas rather than not enough though.
[/b]

I haven't started with the starting fluid just yet, but I rented Murray's scan tool and it actually reads the car, I have a misfire in CYL 4, it has a brand new plug, new wire, and my MSD coils which were working on my GP. So, I'm looking at a new injector, correct? I can noid light it just in case to check for a pulse, but if it was having electrical problems, it would affect more than one cylinder, so should I just get a new injector for it, or should I look at something else. Also, my O2's jump from like 80 to 900, back and forth, is that "normal". I really suck at electronics and the computer controlled crap on these car, so when I see these readout, I'm not really sure what is good and what is bad.
Thanks
CJ
[/b][/quote]

start the car, let it run just a minute or less. pull plug #4... is it covered in fuel? if it is, then your injector isnt the issue. it would then point to the igniton module... that or you cracked the porcelain on the new plug... swap the plug and wire with the cylinder next to it and see what the computer code gives. if the misfire follows the plug and wire, then you know it's not the ignition module.
[/b][/quote]
I'll give it a whirl, out to the garage I go, and thanks for all help. If it is the ignition module, could I pull the one off the GP to test that theory? I'm gonna try to check the plug first, but just in case.

 

[Toasty]

well, at least according to NAPA, the p/n for the ignition modules are the same.

 

[imported_PaceCarBoozer]

well, at least according to NAPA, the p/n for the ignition modules are the same.
[/b]

thanks again

 

[Toasty]

<div class='quotemain'>
well, at least according to NAPA, the p/n for the ignition modules are the same.
[/b]

thanks again
[/b][/quote]


n/p

 

[imported_PaceCarBoozer]

<div class='quotemain'>
<div class='quotemain'>
well, at least according to NAPA, the p/n for the ignition modules are the same.
[/b]

thanks again
[/b][/quote]


n/p
[/b][/quote]

Ok, swapped plugs and wires with #6, misfire remained in #4, plug was dry when I pulled it. I swapped ICM from the prix, same thing, misfire in #4, so I'm gonna guess i'm looking at an injector.

 

[Toasty]

<div class='quotemain'>
<div class='quotemain'>
<div class='quotemain'>
well, at least according to NAPA, the p/n for the ignition modules are the same.
[/b]

thanks again
[/b][/quote]


n/p
[/b][/quote]

Ok, swapped plugs and wires with #6, misfire remained in #4, plug was dry when I pulled it. I swapped ICM from the prix, same thing, misfire in #4, so I'm gonna guess i'm looking at an injector.
[/b][/quote]


kinda looks that way

if you're careful you could swap injectors to double check

 

[imported_PaceCarBoozer]

<div class='quotemain'>
<div class='quotemain'>
<div class='quotemain'>
<div class='quotemain'>
well, at least according to NAPA, the p/n for the ignition modules are the same.
[/b]

thanks again
[/b][/quote]


n/p
[/b][/quote]

Ok, swapped plugs and wires with #6, misfire remained in #4, plug was dry when I pulled it. I swapped ICM from the prix, same thing, misfire in #4, so I'm gonna guess i'm looking at an injector.
[/b][/quote]


kinda looks that way

if you're careful you could swap injectors to double check
[/b][/quote]

I was considering it, but don't know if I want to go through the work of taking it apart twice when I find out it is the injector. I'm gonna check it with a noid light before I do the injector just to make sure it's not the plug.
Damn, at 90 bucks an injector, maybe I will take to time to be damn sure that is what is the problem.

 

[Toasty]

<div class='quotemain'>
<div class='quotemain'>
<div class='quotemain'>
<div class='quotemain'>
<div class='quotemain'>
well, at least according to NAPA, the p/n for the ignition modules are the same.
[/b]

thanks again
[/b][/quote]


n/p
[/b][/quote]

Ok, swapped plugs and wires with #6, misfire remained in #4, plug was dry when I pulled it. I swapped ICM from the prix, same thing, misfire in #4, so I'm gonna guess i'm looking at an injector.
[/b][/quote]


kinda looks that way

if you're careful you could swap injectors to double check
[/b][/quote]

I was considering it, but don't know if I want to go through the work of taking it apart twice when I find out it is the injector. I'm gonna check it with a noid light before I do the injector just to make sure it's not the plug.
Damn, at 90 bucks an injector, maybe I will take to time to be damn sure that is what is the problem.
[/b][/quote]

if you are not getting fuel on the plug, it's not the plug's fault

i only really suggested swapping 2 injectors just to make sure that it isnt a wiring harness issue or fuel delivery issue to that cylinder.

 

[Turbocharged400sbc]

I was considering it, but don't know if I want to go through the work of taking it apart twice when I find out it is the injector. I'm gonna check it with a noid light before I do the injector just to make sure it's not the plug.
Damn, at 90 bucks an injector, maybe I will take to time to be damn sure that is what is the problem.
[/b]

i think i know what your problem is...i've seen it before and it should have hit me when i read this:

.............I am considering maybe a clogged fuel filter cause the car has sat for about 8 months without moving except for this last week. ...........CJ
[/b]

you my friend more than likely have a gummed up injector inlet screen...i've seen this in everything from a TPIv8 to quad4's that have sat for a while, the fuel turns into a varnish in the fuel rails and when the pump is primed/engine cranked the fuel pressure will force the gum into the screen completly plugging it, i'm willing to bet that you have good noid light activity and i'm willing to bet that if you energize it with + &- 12v you will hearit click, but if you do a injector balance test i bet the fuel pressure doesnt go down when #4 is activated...

I bet you didnt throw any StaBil gas stabilizer before it was in storage eh?

the inj is a 19lbhr injector and although the PN is different i have used TPI/LT1 injectors (used) with a 92 L27 (customer needed a dirt cheap repair...and i had the injector in my toolbox) i would bet that a SII L36 injector would work as well though the spray nozzle design may be different as long as it sprays the fuel in a mist it should work well

IF THE FOLLOWING doesnt work you will have to have it professionally cleaned....

First pull the rail and lines together, remove the coils (safety first), and have a friend prime the engine by turning the key on
(fuel pump will prime for 2 seconds and will usually get close to max fuel pressure, or you can find the red wire with the lonly gray connector, this is the fuel pump prim connector, apply 12v+ to it and you will not need a friend-this red wire and gray female spade terminal connector are usually located in a harness breakout near the firewall, and on the FWD's near the passenger side of the car, but is not always the case, it may be near the master cylinder/booster)
at which point take a couple of jumper wires and trigger the injector...i bet nothing comes out (aka no spray, you did state the plug was dry, but i dont know if you checked this properly by cranking with the ignition disabled-do not disconnect the ICM, remove the coils, the ICM signal is required for inj actuation)

at this point yank the injector out and i bet you wil find a golden brown sludge plugging the inlet screen, take a small safety pin (T pin etc) and clean the majority of the gunk out of the injector, DO NOT POKE THROUGH THE SCREEN!!!!!!!!!!!!

now take the injector to a bench and take a rubber tipped blowgun at ~ 40-60psi air pressure (dont do it with a fully charged compressor, i just wouldnt recomend it...) put it on the spray nozzle end (the end that goes into the intake) and with the jumper wires connected and the injector solenoid activated, blow air through the injector, this should blow most of the crap out...
(i still usually follow up with the following steps anyways)

if you do not have access to air this will work but may not be the best...

with the injector closest to the fuel pressure regulator removed prime the rail to flush any remaining gunk out of the rail (just once or twice with the key should be sufficient

install the injector into the fuel rail BACKWARDS, prime/run the fuel pump (you did find the fuel pump prime connector right? lol) and trigger the injector (make sure those coils are removed) it wont spray fuel out the injector inlet it should dribble out, now pulse the injector while the rail is under pressure (rapidly connect/disconnect one of your jumper wires) do this for ~10-20minutes till you see that it backflows the same amount of fuel as one of the other injectors, the best thing you can do is put new gas in the tank as it will disolve the varnish a good bit better than 8 month old varnished fuel

you should now have a relativly glean injector, pull it back out an look at the inlet, you should now be able to see the fine mesh plastic inlet screen fairly clean (it really doesnt have to be perfect but as long as more than 50% of it is clean) if not take a can of carb cleaner (berryman B12 is very good) and the supplied straw stick it into the inlet and point away from you and spray a few times and then go through a shorter backflush sequence again if neccessary

slap it (any other removed injectors) back into the rail in the proper direction (inlet screen at the rail) prime the rail/fuel pump and trigger it and another couple injecotrs and you should see a decent spray pattern comparable to the others that you test

slap it all back together and enjoy your labor intesive but dirt cheap repair job

i hope that has helped you some, it's cheap and has worked for me in all but a few cases, as i said an air compressor makes this faster but isnt really neccisary

good luck with your 5 cylinder 3800 :lolsign:

 

[imported_PaceCarBoozer]

<div class='quotemain'>
I was considering it, but don't know if I want to go through the work of taking it apart twice when I find out it is the injector. I'm gonna check it with a noid light before I do the injector just to make sure it's not the plug.
Damn, at 90 bucks an injector, maybe I will take to time to be damn sure that is what is the problem.
[/b]

i think i know what your problem is...i've seen it before and it should have hit me when i read this:

.............I am considering maybe a clogged fuel filter cause the car has sat for about 8 months without moving except for this last week. ...........CJ
[/b]

you my friend more than likely have a gummed up injector inlet screen...i've seen this in everything from a TPIv8 to quad4's that have sat for a while, the fuel turns into a varnish in the fuel rails and when the pump is primed/engine cranked the fuel pressure will force the gum into the screen completly plugging it, i'm willing to bet that you have good noid light activity and i'm willing to bet that if you energize it with + &- 12v you will hearit click, but if you do a injector balance test i bet the fuel pressure doesnt go down when #4 is activated...

I bet you didnt throw any StaBil gas stabilizer before it was in storage eh?

the inj is a 19lbhr injector and although the PN is different i have used TPI/LT1 injectors (used) with a 92 L27 (customer needed a dirt cheap repair...and i had the injector in my toolbox) i would bet that a SII L36 injector would work as well though the spray nozzle design may be different as long as it sprays the fuel in a mist it should work well

IF THE FOLLOWING doesnt work you will have to have it professionally cleaned....

First pull the rail and lines together, remove the coils (safety first), and have a friend prime the engine by turning the key on
(fuel pump will prime for 2 seconds and will usually get close to max fuel pressure, or you can find the red wire with the lonly gray connector, this is the fuel pump prim connector, apply 12v+ to it and you will not need a friend-this red wire and gray female spade terminal connector are usually located in a harness breakout near the firewall, and on the FWD's near the passenger side of the car, but is not always the case, it may be near the master cylinder/booster)
at which point take a couple of jumper wires and trigger the injector...i bet nothing comes out (aka no spray, you did state the plug was dry, but i dont know if you checked this properly by cranking with the ignition disabled-do not disconnect the ICM, remove the coils, the ICM signal is required for inj actuation)

at this point yank the injector out and i bet you wil find a golden brown sludge plugging the inlet screen, take a small safety pin (T pin etc) and clean the majority of the gunk out of the injector, DO NOT POKE THROUGH THE SCREEN!!!!!!!!!!!!

now take the injector to a bench and take a rubber tipped blowgun at ~ 40-60psi air pressure (dont do it with a fully charged compressor, i just wouldnt recomend it...) put it on the spray nozzle end (the end that goes into the intake) and with the jumper wires connected and the injector solenoid activated, blow air through the injector, this should blow most of the crap out...
(i still usually follow up with the following steps anyways)

if you do not have access to air this will work but may not be the best...

with the injector closest to the fuel pressure regulator removed prime the rail to flush any remaining gunk out of the rail (just once or twice with the key should be sufficient

install the injector into the fuel rail BACKWARDS, prime/run the fuel pump (you did find the fuel pump prime connector right? lol) and trigger the injector (make sure those coils are removed) it wont spray fuel out the injector inlet it should dribble out, now pulse the injector while the rail is under pressure (rapidly connect/disconnect one of your jumper wires) do this for ~10-20minutes till you see that it backflows the same amount of fuel as one of the other injectors, the best thing you can do is put new gas in the tank as it will disolve the varnish a good bit better than 8 month old varnished fuel

you should now have a relativly glean injector, pull it back out an look at the inlet, you should now be able to see the fine mesh plastic inlet screen fairly clean (it really doesnt have to be perfect but as long as more than 50% of it is clean) if not take a can of carb cleaner (berryman B12 is very good) and the supplied straw stick it into the inlet and point away from you and spray a few times and then go through a shorter backflush sequence again if neccessary

slap it (any other removed injectors) back into the rail in the proper direction (inlet screen at the rail) prime the rail/fuel pump and trigger it and another couple injecotrs and you should see a decent spray pattern comparable to the others that you test

slap it all back together and enjoy your labor intesive but dirt cheap repair job

i hope that has helped you some, it's cheap and has worked for me in all but a few cases, as i said an air compressor makes this faster but isnt really neccisary

good luck with your 5 cylinder 3800 :lolsign:
[/b][/quote]

well holy shit, thats ALOT of info.
However, I have a no pulse at the wire. The messed up thing is that the scanner was telling me I had a misfire on #4 (back middle cylinder, if you are looking at the engine from the front of the car) but I had the dead noid light on #5 (front left), the remaining injector wires were pulsing just fine and the engine bogged down even more when I pulled the wires on all except #5. When I pulled that one, the engine RPM didn't change at all. Maybe the scanner was wrong or I'm just gonna be utterly confused. I'm gonna pull the split loom back and track the wires, put a noid light jumper where they end and see if I get a pulse.
Also, no, he never put any stabil in the tank, but it has had a fresh tank of 93 ran through it since the old gas was gone. On a side note, I'm gonna print up that last post to keep as a reference for future use.

 

[Turbocharged400sbc]

well holy shit, thats ALOT of info.
However, I have a no pulse at the wire. The messed up thing is that the scanner was telling me I had a misfire on #4 (back middle cylinder, if you are looking at the engine from the front of the car) but I had the dead noid light on #5 (front left), the remaining injector wires were pulsing just fine and the engine bogged down even more when I pulled the wires on all except #5. When I pulled that one, the engine RPM didn't change at all. Maybe the scanner was wrong or I'm just gonna be utterly confused. I'm gonna pull the split loom back and track the wires, put a noid light jumper where they end and see if I get a pulse.
Also, no, he never put any stabil in the tank, but it has had a fresh tank of 93 ran through it since the old gas was gone. On a side note, I'm gonna print up that last post to keep as a reference for future use.
[/b]

OK did you check with a noid light or a test light? test lights (except some cheapo one's) dont always light up under inj pulse when checking from one Inj terminal to the other...

do you have constant +12v at one wire (KOEO)? if not check the splice (1 wire to 6) in the injector harness
if you have constant power but arent getting the switched/pulsed ground from the PCM skip checking the wire and check it directly at the PCM, the PCM board may have an internal circuit breakage (this is usually more common on older PCM's but every now and then i see it on 92 and later GM's) or a Quad driver failure.

on the subject of the code/scanner OBD1.5 didnt have all the bugs worked out of the PCM missfire diagnostics, most of the time with a snap-on brick (MT2500) i will find that it will show 2-3 cylinders misfireing and it usually is the one with the higher missfire counts but not always...so take what the PCm says with a grain of salt.... if anyone has scanned missfires on a 96+ you will see what i am talking about with multiple cylinders showing MF counts but one is always majorly higher than the rest on a single cyl missfire, and thats with GM's improvments to the missfire filters, earlier 1.5's will usually have high counts on the actual cylinder and just as high of counts on the prev and post fireing cylinders

i learned many years ago OBD1.5 sux but not as much as early ford EEC systems...