To test that theory for yourself, remove the belt, start it and see what happens.

 

So I reread the whole thread and started thinking about OrangeBird's idea about plugged cats. I do recall spinning into snowbanks repeatedly and jamming the exhaust system causing cars to run crappy or not at all. So what happens if you a) drop the exhaust at the y pipe or b) pull the air filters in case the car swallowed something.

 

A is non optional , B... the whole tpi air cleaner was removed when troubleshooting started. The filters aren't damaged, nothing in the cavities that hold them, nothing jammed anywhere up to the tpi.

 

Should have added when I was young and foolish (as opposed to now older and foolish) I spun cars into snowbanks... Spouse frowns at any rally techniques in the winter. Just was thinking what if somehow the exhaust was plugged. Clearly not snow related. Oh well.

 

To substitute dropping the exhaust, what about removing the large rubber hose (from the AIR tubes) and forcing compressed air through the exhaust?

 

That idea was a crap out too, swapped alternators with a known good spare and issue remained.

 

Done for the night, diagnostics are exhausting. I've tested and troubleshot every component I can think of, run every test suggested. I'm going to have to simplify this down to the 3 basics...

Air: Starter cranks engine over / Throttle blades open freely and aren't obstructed. What else goes into this? If something crawled in the tailpipe, it shouldn't make it past the muffler, and force running it should blow it out right?
Fuel: 40ish psi at the rail with koeo & the mid to high 30's force running w/ foot on gas. How long after fp prime should the 40ish psi hold? Hope it's not a leaking in-tank pump coupling hose. I'll attempt a fuel system diagnosis tomorrow...
Spark: Before and after distributor replacement the spark checker flashes when connected between coil & cap as well as to the number one plug. Just shy of zapping myself I'm almost sure I've got spark.

anything any of you can think of... post it please.

 

if the engine is actually running, to me that rules out fuel and spark. If you have to keep your foot on the gas to keep it running, that seems like an IAC problem??

 

I do have a noid light kit with IAC tester but the instructions HF included left me with questions. Idk if I'm supposed to assume as long as the 2 led's are flashing back and forth the ecm is trying to command the iac? Concluding the iac itself is isn't moving as commanded?

I'm glad you brought that up. Earlier on I tried to remove the iac and clean it and all passages, but my adjustable wrench wouldn't fit. I'll try again tomorrow. Thanks.

 

Open your throttle blades a little and see if you can get it to idle. If it does then it could be a bad IAC.

 

I like where you're going with the bad IAC idea ULTM8Z.

 

I agree with the IAC idea but thought it mainly controlled at idle. If it's clean and tests OK then your stuck buying a new one. You have fuel and fuel pressure, you have good spark,you have air coming in but it's like something is a drag on the engine causing it to stall out. All snow bank joking aside, I doubt the back half of the exhaust is blocked but you've all watched reality TV where stuff comes blowing out the tailpipes. I know the car was just running but at this point, what the heck. And if you aren't running a cat disregard this but I quickly googled this.https://blog.rainbowmuffler.net/blog...ytic-converter

The other guys might have more experience but I wouldn't think compressed air thru the system would clear much if that's the problem. A true head scratcher for sure.

 

The iac was seized in the throttle body, removed the whole tb yesterday, removed the iac, the pin thing was stuck out caked with carbon. Cleaned the entire tb, even lubed the blade shaft, put in 1 of my many spare iac's, reinstalled today and... wait for it... wait for it...

SHE FIRED UP AND RAN ON HER OWN! Now I owe you a 12pk

 

I’m still not understanding the goofy voltage at injectors. Or what a force run is.

 

Sweet... only took 118 posts to get there! Lol...

What an ordeal... but glad you got it worked out.

 

Force run => itll run if he keeps his foot on the pedal and opens the throttle blades.

 

Gotcha, odd about injector power. Threw me off. Glad you got it fixed Eugene.

 

This was a well needed learning experience, Thanks Tuned P!

 

Man, what an ordeal. Great to hear it's working again.

Brian

 

I will second that. Now go do a burnout.

 

hello all,
89 iroc z. Car was running fine but wouldn't start one day.. i looked every where and found i was getting a pulse to the injectors on the drivers side but not the passenger side. I looked up the codes and found all i was getting was a code 12... can anyone give me an idea of how to fix please

 

You will have more success sticking with one thread.