96z28_lt1

thats the thing i can't even keep it alive long enough to drive it, i bought a scanner with the freeze frame and live readings going to see what IAC counts are and such

edit: i don't think its an actual mass air flow problem but if it turns out to be i will let you know thanks for the offer though

96z28_lt1

I also found a wire unplug im not sure what this wire goes to i know what all my other unpluged wires go to but can not figure this one out

it comes out of the firewall on the drivers side i found it resting behind my intake by the disconnected egr wire

Injuneer

Looks like the connector for the EGR vacuum solenoid:

http://shbox.com/1/harness1.jpg

http://shbox.com/1/egr1.jpg

96z28_lt1

thats what i thought also but the egr solenoid plug is still there this has thicker wiring it also on has about 2.5 volts with key on

changed fuel filter, nothing better tested spark at spark plugs
trust me i got that it fealt real nice..haha i no longer feel like its fuel or spark i sprayed maf cleaner in the throttle body see if that had any difference but no, what are signs of bad compression i mean i can get it to start and rev somewhat with valve covers off but that was with WOT start now it only starts and pops occasional backfire but won't stay started..... so aggitated ready to just order all new gasket and tear it down and do it again

Kevin Blown 95 TA

You can ground crank it and hear if it cranks unevenly like _ _ _ _ - _ _ _ _ _ _ _ - _ _ _ where it turns faster on the bad cylinder the pitch of the cranking sound will change to a higher note. And if your valves are screwed up you can ground the coil wire and have someone crank it while you open the throttle body and listen in there for a whooshing sound if one or more valves aren't closing all the way, harder to do for exhaust valves on a catted car, but might be possible. Just some basic diagnosis. Also recheck your ignition wires at the distributor. If you still can't get it running, make sure your plugs aren't all loaded up with junk.

OneShoe50

Maybe a giant vacuum leak? And I think your on the right track with the IAC. Is the line from the intake to the brake booster ok? Just a guess based on your information, good luck.

96z28_lt1

going to get compression gauge tomorrow from autozone, maybe i should try a vaccuum gauge also? What is ground cranking? I have another video of today that i can put up. Any reason the opti could be bad but still send signals and spark? Also have another video of crank starts today i'll upload here in a couple minutes, i'm just so lost i've been hoping for something easy so i don't have to rip this car apart again but its not looking that way, also what would make it fire up better under certain throttle conditions? It also fired up better with valve covers off?

96z28_lt1

brake booster line is good, The scanner i got today threw come codes with MAF detached from the intake system but still pluged in which is the only time it ran long enough for the car to get codes and a read some of the things was crazy like 42 volts for tps i didn't take any of the information down though due to the maf not actually involved in the intake system and it just being open throttle body. I might pull IAC out tomorrow and just look at it i can't reset it because the car won't even idle or hold rpms where i want them to. Also this car was a traction control vehicle that i got rid of the cable module for a non traction control throttle cable not that it shold make a difference

codes were po102
and like a po336 or something to do with crank position sensor
also a po100

edit: i figured out where that cable goes to it was for the traction controle module.. i feel dumb haha

Injuneer

Did the mystery harness connector go to the TCS throttle relaxer on the valve cover?

96z28_lt1

It did before i deleted that. Another question i have is if anyone has ever had a problem similiar to this doing method one for the valve lash and pre load of shboxs site, thats how i've done it but i'm not sure if doing it that way will still make the adjustments right i could be wrong though

96z28_lt1

video from earlier today after first attempt i figured out the sweet spot and the last try it almost dies but brings itself back to life once or twice.... if anyone can make anything out of that sorry its phone video also.... this was with maf plugged but off throttle body i believe

http://youtu.be/eiF0q6522Zs

96z28_lt1

IAC test says to test for continuity on the coils.... curiousity as to if they mean the harness or iac itself because on the harness i have none which seems like a problem....

96z28_lt1

fuel pressure regulator.... pretty sure makes sense to me right now need to get fuel pressure gauge on it. Heres what i did tryed to start tryed to start starts then dies, check the schrader valve by pushing pin no fuel... only starting during part throttle is do to some vaccuum letting the diaphram let fuel in but not much? So it starts then dies? I don't know if this sounds logical or not

Injuneer

The IAC is a stepper motor. It has two magnetic coils inside it, that move the pintle inwards and outwards. There are no separate "coils" on the harness. You unplug the harness and test the contact pins on the IAC.

http://shbox.com/1/iac2.jpg

Injuneer

The fuel pressure regulator is on the return fuel line. The spring holds the pressure in the rails at 43.5psi, by closing down the return flow. The vacuum diaphragm moves the spring so that the fuel rail pressure drops, proportional to the intake manifold vacuum, so that there is always 43.5psi DIFFERENTIAL pressure between the rail and the intake manifold.

The diaphragm doesn't open the regulator to let fuel in, it adjusts the return to the fuel tank to hold the pressure setting.

Starting, and then dying with no fuel pressure in the system is often the sign of a clogged fuel filter. Enough fuel seeps past the filter to get it started, but once it starts, the filter can't pass enough fuel to keep it running.