Running rough

[secondchance]

Originally Posted by Tony91

ok, I started it up ran fair, started to pull plug wires1 at a time I could hear the idle drop on most cyclinders. #3 had the least amount of change, than #4 had the next least. I had to pull #3 off several time to listen if there was any change in the motor. Still think its injectors? I really appreciate all the support and feedback.
Tony

Any difference in how rough the motor is running depending on engine temp?
Reason I am asking is, at least in my case, my 94 would run just fine until engine temp hit around 190 or so.
At first, I thought it was open loop/closed loop issue. It turned out, at least in some cases, injector would run fine until it heated up at which point it would start to short out internally.
Also, #3 and 4 are not on the same coil. I think #4 and 7 and #3 and 2 are correct pairing for coils.

[Tony91]

I let it warm up but maybe I didnt let get warm enough, I 'll try again later, gonna do some reading on pulling the plenum..

[secondchance]

Originally Posted by Tony91

I let it warm up but maybe I didnt let get warm enough, I 'll try again later, gonna do some reading on pulling the plenum..

Check these link also.
http://www.corvetteactioncenter.com/...8/002/article/

http://www.corvetteactioncenter.com/...procedure.html

Since 2002 I must have pulled the plenum 4-5 times. Good news is that it gets easier every time.

[tccrab]

Some GREAT pics and very clear/concise info in these threads here on the forum:
http://www.zr1netregistry.com/forum/...ead.php?t=7614
http://www.zr1netregistry.com/forum/...ead.php?t=9123


There's lots more where this came from, just click on the search button and type in "Plenum Pull".

TomC
"Crabs"

[flyin ryan]

If you know somebody that has or you yourself can get your hands on a Tech 1A, it will let you drop injectors one at a time. Same idea as what you just did, rough running when dropped or no change, either way it will help you key in on an injector problem or a bad hole as well, although sounds like you have your cylinders figured out to some degree already. I'm posting this to help you regarding your injectors, specifically.

[Tony91]

So I got home today I took it got it nice and warm and started to miss. I started on the even side, couldn't get to #8 (motor was hot). Not much of a difference, started on the oddside pulled #1 and no difference at all. Again worked down to #5 not much difference and again I couldn't get to #7. So I think the injector in #1 is the problem. I guess I better start my shopping list!

[Tony91]

Not no more!!! I tore it down and cleaned up the nest, installed new FIC injectors and wires, buttoned it up and nothing. I figured out I was getting gas but no spark. After some digging around it turned out that one of the connectors on the coil pack was not all the way in, turned the key and it fired right up!! I do have to say thank you to all that helped-KUDOS!! especially Jeff whom I made quite a few calls

[Paul Workman]

Originally Posted by Tony91

Not no more!!! I tore it down and cleaned up the nest, installed new FIC injectors and wires, buttoned it up and nothing. I figured out I was getting gas but no spark. After some digging around it turned out that one of the connectors on the coil pack was not all the way in, turned the key and it fired right up!! I do have to say thank you to all that helped-KUDOS!! especially Jeff whom I made quite a few calls

Congratz!!! Very gratifying, I'll bet. And that dreaded "plenum pull"? Twas no bik deal either, huh?

Now...You can come over and help me eliminate possible causes of my miss. Mine is wicked - indications are a valve or that it ingested something, but Marc H is not at all sure it is a valve. Got a laundry list of things to check out before pulling the engine and yanking the heads...

P.

[secondchance]

[Tony91]

The plenum pull was not that bad and youre right once it started what a good feeling! I took it out this morning and it ran good and strong, the temp was running higher than normal gonna let it cool down and check the level