Redneckstarterkit

Hey ya'll just wanted to see if anyone has any in site on this symptom.

Its a 1992 3vze ,when the car is cold (first start of the day) it runs great, lots of power and no hesitation and great idle. But, when it gets to operating temperature it starts to mis/hesitate and have a nasty idle. After driving for a while it starts to get better but it still misses at part or 1/4 throttle.

I have changed all the injectors, coolant temp sensor, cap/rotor/wires/plugs/. It has new heads and great compression.

I may change the TPS and O2 sensor but I dont think that can be the issue.

annoyingrob

Has anybody ever cracked open the AFM to mess with it?

How's the timing?

How's the gas mileage?

Redneckstarterkit

Ok so I unPlugged the o2 sensor and the symptoms went away.

The bolts on the o2 are rusted and stripped, and advice on taking them off?

MudHippy

1. They aren't bolts. They're studs with nuts(or atleast they were from the factory).

2. Why are you messing with an electronic component like the O2 sensor without checking for codes first? These types of things don't require much guess work, if any. And it sort of sounds like you've done nothing but.

3. BTW, and try not to forget this when asking a question, WHICH ENGINE?! Some of us know more about one than the other. And it's pretty important in symptom diagnosis to know which it is regardless. Because they are NOT the same. And if you think I want to sift through any/all of your previous posts to find out...think again. That may just be enough to make me skip right over your query, and go on to the next. Leaving you to fend for yourself. And, in fact, was a contributing factor in why I'd done so until now. That and the lack of codes recited. Which could turn out be a very big waste of all our time here.

Redneckstarterkit

Wtf mudhippy

Redneckstarterkit

Update the o2 was not the issue

abecedarian

Mudhippy wasn't the issue either.

abecedarian

Yeah, okay.
The OP said >snip< {my response}

That is unless the OP was edited after you said that and before I read it, in which case I apologize.

abecedarian

Now, timing and idle speed are set with the engine warmed up.
Warm the damned thing up, drive it a few miles, then go about setting the idle and timing. You may find it runs like crap afterwards during cold starts. So then you fix the cold start issues since those are not part of normal.

Redneckstarterkit

*** UPDATE ***

So after getting a lean reading I check and replaced my coolant temp sensor, TPS, sensor, all injectors, vacuum lines, O2 sensor, cleaned my egr and manifold, and fuel filter it was still hesitating.

There was one thing left that i neglected and feared to since it cost a lot to replace and it was the MASS AIR FLOW METER.

I finally bit the bullet and replaced the MAF and presto!!!!! this thing is good as new and runs like a champ. SO much power again.

Thanks for the help yall

Pat8942

If one replaces enough parts, sooner or later they get lucky, but it's much cheaper to spend time diagnosing the problem than to just be a parts changer and never really know what the real problem was. Just my opinion.

Redneckstarterkit

I'm with you on that, I'm a level 4 out of 10 in skill but learning.

ThatGuy1295

X2
Not how NASA does it, why should you? Get IT?