when my engine is cold i discovered if i blip the throttle it will studder bad, and if i do it a few times i can manage to kill the engine, now when it warms up it still does it but not nearly as bad and i cant kill the engine even if i try..

now i was thinking its the 02 sensor giving a wrong fuel mixture and maybe its running rich and thats whats causing the studder. or could it be the timing?

i also know when ever i try to get on it from idle, it bogs real bad for a quick sec before it catches on.

 

Do you know how to test the tps sensor?It coud be out of adjustment or bad.

 

ahh yes thanks im gonna go check that out

 

ok I replaced the TPS and that didnt effect anything. still idles fine, a little high usually. (around 1k) but still, when i blip the throttle at all it bogs bad. now im thinking o2 ?

 

sounds like o2 or maybe even MAF to me... I've read the bosch heated o2 sensors are great, although the install is a little more involved than a OEM replacement sensor. I'd say try the o2 first. When's the last time your car had a thorough tuneup?

 

The 3 wire heated O2 sensors from GM (marked AFS-74) are a lot better than the Bosch in my opinion... and I've used several of both.

 

I stand corrected

 

whats the price tag through the dealership on those?

 

1) The o2 sensor is not used in open loop. Which is when he is having the problem.

2) The TPS is used to set thresholds. Its not his problem trust me.

In open loop, when cold its rpm vs map, or rpm vs load if its a MAF car.

Prolly a fuel problem, I.e, fuel injector, might even be a vac leak. When its in closed loops, your BLMs are prolly way off but the ECM is correcting enough to make it un-noticeable.

*could* be the maf. No code though? odd.
I suppose it could be returning the wrong grams per sec.. But I doubt it.

-- Joe

 

every once in a while with a cold start ill get the code 32 (egr) but thats it. would a stuck open or closed EGR cause this problem? maybe an injector is bad? any way i can test those? maybe a fuel injector cleaner wouldnt hurt?

 

dunno about the EGR, but you can test the ohms on the injectors. directions here. think they're supposed to be around 12.5, but I've heard of them being as high as 16. most importantly, check for consistency; if one or two are low or high, then you've got bad injectors. unfortunately, even if they have the correct resistance, they may still be dirty and clogged. gotta remove and inspect them to be sure. A bottle of injector cleaner wouldn't hurt. I use LucasOil fuel injector cleaner and upper cylinder lubricant or whatever its called. get back to us with some ohm readings.

 

well tomorrow im swapping intake manifold bases, so this will be my prime chance.

would it be ok to submerge my injectors into some injector cleaner while they are out of the engine and let them soak?

 

I don't know if thats a good idea.

Best thing is to have them flow checked and sonic cleaned.

Anyway, EGR could cause a problem if its sticking. I didn't think of that before.
Might want to replace it while the intake is out, or block it off temporarily.

-- Joe

 

Depends on how off they are.

Injectors are so cheap now, servicing used injectors is almost not worth it. You can get LT1 injectors from SLP for what, $100.00 ?

-- Joe

 

I didn't say that it wasn't worth it to just replace them and be done with it. I don't claim to know jack about injector design, but I'd imagine what is available now is an improved design than what was available in the 80s, so it would be something to think about anyways. I was Just stating that I'd go buy a $5 meter at walmart (if I didn't already have one) and check the ohms on my injectors before dumping $100 to rip my intake off and replacing the injectors. If I were not pulling my intake off anyway, then I probably would buy a set of replacement injectors in case I decided the originals were dirty and needed to be swapped out.