Dead Miss, cant find it

[striker_29]

My car has a low RPM dead miss that I cannot find. If I keep my foot light on the accelarator I get a steady and constant miss. Give it a little more gas, it dissapears and she purrs like a kitten. Car has good power, and pulls hard when at Wot. Low Rpm's produce the constant miss. FP is good @ 42 line off. Just replaced plugs, fuel filter, egr, and chip but the miss is still there. I was thinking maybe plug wires, but they are just a few months old and they look fine to me. Loose ground somewhere I'm missing? Any suggestions are welcome to help me figure this out...Thanks

 

[FlyinGN]

what plugs? Anything but ac 43's make my car run funny..

 

[Carolinaturbot6]

Mark, did you happen to check the little egr filter? If it's clogged up, it will sometimes cause what you're describing. Just a shot in the dark, but hey.

Maybe it would help if you took some readings with direct scan under the light throttle conditions. Maybe something will stick out that the more knowledgable fellas here will notice.

 

[striker_29]

FlyinGn, They are Autolite 23's gapped at a tight 35. I wonder if I should try the AC's ???

Carolinaturbot6,

Someone else mentioned that egr filter to me, but I have not seen it. I will look again for that and check it. Also, as soon as I get home I can get some Ds readings and I will post. Thanks guys

 

[Carolinaturbot6]

Just to the right of the egr valve, sits the egr vacuum control assembly (black & square). You'll see a plug connection going into it on your right side. The filter is just below this plug inside the little plastic cap. Just squeeze & pull a little & it will come right off. The filter will be right there. HTH

 

[John Larkin]

Sometimes TPS voltage isn't linear. I've read threads where people have had dead spots. Press the pedal slowly and watch the numbers to see if they move up in steady increments. I don't know squat about DS but at 18 fps? it should pick it up if it exists.

 

[striker_29]

Carolinaturbot6, thanks I will check that out as soon as I get off work today. And John, that is a very good idea. I would not have thought about that at all. Dead spots in the tps....hmm, very well could be. Thanks again.

 

[Brian Mc]

striker 29 my car has this same problem right now, a slight miss that causes turbo lag and shudder when the tcc is locked up. can't trace it to any particular cylinder, buick dealer manager says dirty injectors but i have tried to clean them with no luck. i am going to check this egr tonight, but i think it's something else. my car is bone stock and its doing this. it runs fine once the boost is up. its driving me nuts right now.

 

[T-Type Mike]

just a shot in the dark, but could it be the Mass Air??

 

[salvageV6]

Bad plug or wire is my guess. I would double check them after the EGR deal.

Try AC CR43TS's they work great at .0345 gap.

Caspers coil pack and ignition tool with wire testers is great for this kind of work.

 

[Steve Wood]

Being that it does it at very low throttle....I would consider the injectors and the tps.

 

[striker_29]

Well thanks for all the replies. It's been raining like crazy here so I didnt drive the car yesterday, but I did check the Tps voltage as John suggested and it seems to rise very smooth as it should. No irradic jumps or anything like that so Im guessing thats ok. The injectors are 009's less than 5000 miles on them for sure, but I have heard of this type of problem with them. I am going to change to the ac plugs and see what happens. I think I can borrow a Caspers tester, anything special to look for? Thanks

 

[salvageV6]

Get the spark plug wire testers with the caspers unit if the owner has them.

Check spark from low to high rpms on both the coil pack and wires.

I'd still pull the plugs as I found a crushed electrode on #6 on the GN a week after I put them in. Miss drove me crazy and I think it was the top engine cleaner that may have loosened something that smacked it. Either that or i dropped it or something.

Worth checking only a half hour or so.