Rough Idle/Hesitation/Backfire

[flyin ryan]

Originally Posted by Gary Yarbrough

Don't get me wrong, I fully trust Jeff's opinion that the belt isn't causing the hesitation and I am very grateful for his and everyone else's advise! I was just asking if it is a problem in a more general sense. The loud clapping sound that seems to be coming from it when I floor it from idle doesn't seem like a good thing. But, I've got a lot to learn...

The learning never stop for all of us Gary. Your keeping your ears open & paying attention, that's all good . This noise your talking about from idle, is it when your in neutral/park, under load/power or both?

[Gary Yarbrough]

Code 63! Today I took the car for a long drive (120 miles) and I got the dreaded SES light. When I got home, I pulled the codes and got code 63 (it flashed this code three times). I just changed the left oxygen sensor. Could this mean that I need to change the right one too? Could this be the source of my issues?

Hopefully, tomorrow I'll get time to do all of the other checks that Jeff suggested. I'm so swamped right now that it is hard to get anything done!

[bldavis11]

I would say you're up for the starboard oxygen sensor!

[GregCrowe]

Start on this page and keep reading:

http://zr1netregistry.com/forum/show...t=1777&page=16

Those Accell coils are garbage. They made my car run like complete crap, backfire, etc.

[Gary Yarbrough]

Crap! I changed the second 02 filter and it's no better (well...it actually seems to run stronger on the top end, but it could be my imagination since I haven't slept much this week). It is now "backfiring" again. The "backfire" is coming from the plenum area for sure. Hopefully, tomorrow I'll get time to ohm out everything. I've got to get some gaskets ordered, I've run out of spares... I sure hope that my Accell coils aren't the problem.

[flyin ryan]

Got to say I feel for ya'...your having a tough go of it Gary. Just keeep telling yourself, 'It's something, It's something'...just have to pin-point it . Keep your chin up, bud

[flyin ryan]

When is it backfiring 'Exactly' Gary? Off idle, light load, Trottle 'Tip-In', W.O.T. (Wide open throttle) under load (power) .

[Gary Yarbrough]

The backfire only happens if I am at idle and I go to W.O.T. If I'm just parked and I go from idle to W.O.T. it only does it some times. If I'm coasting (say 7-8 mph) and go to W.O.T. it does it 80-90% of the time. So I'd say that it is worse under a load.

[ittlfly]

Originally Posted by GregCrowe

Start on this page and keep reading:

http://zr1netregistry.com/forum/show...t=1777&page=16

Those Accell coils are garbage. They made my car run like complete crap, backfire, etc.

Did you read this link as suggested by Greg? Especially pages 17 & 18? Your problem sounds very similiar.

[Gary Yarbrough]

I did read the link as suggest by Greg.

I checked the resistance of the coils I removed and here is what I got:
0.6/5.7K
0.6/5.69K
0.7/5.88K
0.6/5.62K

So, I don't think coils were my problem to begin with. However, I could be wrong and would be glad to hear it if I'm thinking about this the wrong way.

Maybe today I'll get time to pull the plenum back off and ohm out the plug wires and new coils.

I have noticed something else that might be relevant. When I'm sitting and I go from idle to W.O.T., I can hear a bit of a sucking noise for maybe 1-2 seconds. Could I have a vacuum leak or is a sucking noise from the throttle body normal?