car is misfiring nasty style at anything under 35-40% throttle.

[02BlueGT]

did they ask permission to use gtpmike's pic for that chart?

No, but Denis didn't ask before he did GTP mike damage to his car either

I've had that pic since high school, but I googled it cause I'm too lasy to upload to photo bucket.....

 

[Turbocharged400sbc]

dennis is talking about 150 shots and blizzaks

 

[Yaj Yak]

lol wtf

 

[02BlueGT]

lol wtf

You fix your car yet ?

 

[Yaj Yak]

goin outside shortly...

 

[Turbocharged400sbc]

damn near 2 hours for you to check yer plugs? or did yer pecker freeze to the fender

 

[Yaj Yak]

haha no.. .i just pulled the icm/coil packs and that plate that it all sits on... everything had some corrosion on it, so i cleaned it all off... car has plugs in it that are less than 10 miles old right now... put the coil packs and everything back on- it idles nicely... starts driving nicely... then like 4-5 minutes into driving it/it running... it starts doing it again... its violent... the car shudders and the rpm's bounce all over the place and the best way to keep the car moving is to manually shift it down to keep the rpm's up to keep it from misfiring/stuttering... also. i checked fuse 21- and it is all good- i even replaced it with a known good fuse to just make sure.

 

[Eagle]

no spare packs laying around to test with?

 

[Yaj Yak]

I gotta grab em from devins house... thats the next step.... then if that doesnt change anything... i dunno- the o2 sensor thing, along with prolly tryin another maf that i have in it...

 

[Mike K]

So was the car cold or warmed up when the problem started? It sounds like the car started fine and then once it warmed up got into trouble.

I would almost suspect a crank sensor or some other sensor is failing as it warms.

 

[Yaj Yak]

yep. it starts fine, drives fine, and then it warms up and starts messin up...

crank sensor tho really?

 

[Eagle]

Wouldnt he like instantly get a code to that effect? Computers are pretty good about detecting that sort of issue...

 

[02BlueGT]

Wouldnt he like instantly get a code to that effect? Computers are pretty good about detecting that sort of issue...

Sometimes, without a steady engine speed the Tests have a hard time picking up a weakening sensor... I'd say the issue happening once the vehicle warms up could be a ICM , many bad ICM's will only be bad once they are at temp.... try swapping in a known good one ASAP :smile:

 

[wombat]

Kinda going out on just slight knowledge here, but isn't normal op temp like 180s for cars? 162 seems low.. I'm more than likely wrong though

 

[DanJ]

Maybe if you have a 160* thermostat and it's 30* out.

 

[02BlueGT]

Kinda going out on just slight knowledge here, but isn't normal op temp like 180s for cars? 162 seems low.. I'm more than likely wrong though

Most GM cars are 185-195... (most I see are 195).... But 162 is right for a car with a 160* thermostat... cooler engine, denser air, which means more oxegen and fuel,so slightly more power.... other reasons as well like knock prevention leads us to running cooler thermostats

 

[phat_ridegt]

usually a crank sensor will cause the engine to die, or not start.

do you have any scans while it's missing? you should isolate which cylinder it is and determine if it spark or fuel, before you change any more parts....

 

[Turbocharged400sbc]

yeah scan your misfire counters

 

[Yaj Yak]

can any one tell me how to do that with hpt?

 

[02BlueGT]

can any one tell me how to do that with hpt?

In the table view, right click, and select add parameters, it is under engine, then missfire, then it has a total count, and a per cylinder count, turn on all 6 cylinders, and scan

 

[Yaj Yak]

awesome thank you.

 

[02BlueGT]

awesome thank you.

No prob, I got counts on a good running engine, so you should get counts up in the thousands on the bad cylinders

 

[BoostJunki3]

i had the same exact issue and it was a tired coil pack.....if its not that i would guess bad ICM.....

 

[Yaj Yak]

thats what it looked like under my coil packs on the bottom... i cleaned up the top part before i took the pic, bottom i hadnt touched... the back of it looked just like that as well.

 

[Yaj Yak]

k so i actually started playing with my black car today since i have finally gotten some timme.

actually sitting in it scanning right now.

but while i was sitting here... it started to idle like absolute dog shit out of nowhere... look at the scanner, and the maf reads "0 hz"... car is barely running...

i give it gas a few times to keep it running maf comes back to like 2100 and is idling okay...

im going to pull my maf, and spray it with some cleaner, along with take my afc off of my car and bring it inside to see if possibly it got wet or something.


im scanning for misfires right now, and havent seen any at all.