Testing coil packs

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
Testing cop's & fuel filter

Can CoP's be tested? If so, how?

I have an issue of when accelerating that it feels like it wants to backfire. I will be pulling and checking the plugs in a couple of days. I am also thinking the fuel pump may be faulty as well. I read the fuel pressure not to long ago and it was at 32...seems a little low? Is there a way to test that?

Any thoughts.

99 NA Cobra 79000 miles
 

Dragon03

Super hated on
Joined
Mar 28, 2007
Messages
27,350
Reaction score
0
Can coil packs be tested? If so, how?

I have an issue of when accelerating that it feels like it wants to backfire. I will be pulling and checking the plugs in a couple of days. I am also thinking the fuel pump may be faulty as well. I read the fuel pressure not to long ago and it was at 32...seems a little low? Is there a way to test that?

Any thoughts.

99 NA Cobra 79000 miles
I am pretty sure you can get them checked out at AutoZone. I was suspect that I had a pack bad on my Blazer and they were able to check it thru using an Olm Meter and looking for a certain resistance values.

Regarding the wanting to backfire it sounds like it could be a plug issue. When I had my 97 Cobra I had a similar issue but what ended up happening was I had a set of plug wires that didnt completly seat around the plug and I went thru and washed the engine down water got down in there... started her up and that was that I ended up fouling out a couple of the plugs I replaced them out and I was back in bidness. They were crappy ass Bosch Platinums anyway :rolleyes:
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
Hopefully I find the problem myself. I am off Thursday...I will pull them then.
 

SonicBlur

Harvester of Sorrow
Joined
Oct 15, 2004
Messages
5,294
Reaction score
0
Location
Schaumburg
Just unplug each spark plug boot and see if it arcs to the block. If you don't see a spark then you either have:

1. Bad plug.
2. Bad wire.
3. Bad coil.

Just be careful, these are HEI ignitions...they'll scare the crap out of you if you're not paying attention, LOL!

-Mike
 

Dana

Bluesmobile
Joined
Mar 2, 2004
Messages
2,619
Reaction score
0
Find an inductive timing light and wrap the pickup around the leads to each coil, one at a time. I have found that the COP that is misfiring will not illuminate the timing light when the miss occurs.

I have used this successfully on several cars/truck, but YMMV.

Dan
 

rdsnake

formerly RD SNAKE
Joined
Mar 5, 2006
Messages
5,571
Reaction score
26
Find an inductive timing light and wrap the pickup around the leads to each coil, one at a time. I have found that the COP that is misfiring will not illuminate the timing light when the miss occurs.

I have used this successfully on several cars/truck, but YMMV.

Dan

Yep, I used this method. It works pretty good!
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
Thanks for the input guys...I will see what i come up with Thursday.

I was going to at least pull the plugs, but I started drinking. Thursday morning over coffee it is. :biggthump
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
so what was it?
Still got me on this one....It is an intermittent thing, only happening at the lower RPM's.. :dunno:

Plugs looked fine when I pulled them. However, I will be replacing them soon with Autolites. Right now Bosch Platinums are in.

Any suggestions on what to do would be great. I have cleaned the MAF and IAC, and the fuel filter was changed at the end of last year. only 2500 miles ago.
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
Ok, so Autolites are in along with a new belt. The initial test drive had no hesitation. I plan on driving it tomorrow, and see what happens from there.

Hope that is all it was.
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
Ok, so after driving it last night after the change and work today, I am convinced the plugs were the problem.

Replaced with Autolites FTW.
 

99 Stangbanger

Phantom Fury
Joined
Nov 22, 2004
Messages
1,706
Reaction score
0
I remember you saying you had simular issue last summer and I mentioned your plugs then after your power washing the engine and how to seal the coil pack covers.

What gap did you set them at this time?

If and when you get the next chance, skip gapping plugs with the Key ring gappers and use a feeler gauge instead. Much more accurate then the .75 cent gapper in the jugs at the registars at the local part stores. They suck imo!

Sears sells some nice gapping tools:biggthump

Glad you got it fixed though. If the problem comes back, you may have a bad coil pack though. New plugs may disguise it temporilary or intermittently.
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
I remember you saying you had simular issue last summer and I mentioned your plugs then after your power washing the engine and how to seal the coil pack covers.

What gap did you set them at this time?

If and when you get the next chance, skip gapping plugs with the Key ring gappers and use a feeler gauge instead. Much more accurate then the .75 cent gapper in the jugs at the registars at the local part stores. They suck imo!

Sears sells some nice gapping tools:biggthump

Glad you got it fixed though. If the problem comes back, you may have a bad coil pack though. New plugs may disguise it temporilary or intermittently.
I used feeler guages!:headbang: Yes, and thanks for the advice on the covers. No issues with water since then. :biggthump

I hope the problem doesn't come back. If it does, I will start to look a little closer at the coil packs.

Passed emissions as well. :headbang:

All around a good day today! ***so far
 

SVTLSC

Factory Freak
Joined
Oct 29, 2006
Messages
2,790
Reaction score
0
if it happens agian the fuel filter might be plugged
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
if it happens agian the fuel filter might be plugged
Thanks. Even though I changed it last year, it could be bad again...

Here's to hoping that all it was were the spark plugs. :toast:
 

99 Stangbanger

Phantom Fury
Joined
Nov 22, 2004
Messages
1,706
Reaction score
0
Thanks. Even though I changed it last year, it could be bad again...

Here's to hoping that all it was were the spark plugs. :toast:
Glad you used the Feeler gauges:biggthump.

Highly doubt your newer fuel filter gave it up already w/ only 2500 new miles on it. It would take a lot of debris in the tank (Doubt it) to cause that sort of issue your having. If a filter is clogged, it stays clogged thus you wouldnt have this intermentent issues with lag imo. A fuel prsssure test at the rails would rule that out.

BTW...did you get the cleaning advice for the MAF and IAC off my STICKY on CHP? I have alot of good usefull info in Tech on that stuff:D

Did you have your hood shipped or did you find a place local for PU? I'm looking to replace my 2000 R hood in favor of a 95R hood:headbang:
 

99svtdvr

open for business
Joined
Apr 27, 2005
Messages
2,015
Reaction score
0
Glad you used the Feeler gauges:biggthump.

Highly doubt your newer fuel filter gave it up already w/ only 2500 new miles on it. It would take a lot of debris in the tank (Doubt it) to cause that sort of issue your having. If a filter is clogged, it stays clogged thus you wouldnt have this intermentent issues with lag imo. A fuel prsssure test at the rails would rule that out.

BTW...did you get the cleaning advice for the MAF and IAC off my STICKY on CHP? I have alot of good usefull info in Tech on that stuff:D

Did you have your hood shipped or did you find a place local for PU? I'm looking to replace my 2000 R hood in favor of a 95R hood:headbang:
You betcha I got the advice off of CHP...:biggthump I may not post much there but I check out alot of tech sections while chasing issues/problems. Good stuff right there as a sticky!

Hood was shipped. No local place. And I absolutley love it. Makes it look sexy! New pics should be up this weekend!
 

99 Stangbanger

Phantom Fury
Joined
Nov 22, 2004
Messages
1,706
Reaction score
0
Yea I want one also:biggthump Should have got it to start with but we all live and learn from our mistakes.

Is the underside finsihed or it it "open glass matting"
 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Top Bottom