I have been going through the many posts on this topic and have tested/replaced a number of parts, but I am still having trouble.

My car
89 IROC-Z
305 TPI (Engine Code F)
Original Engine 314,000 miles (No overhaul, I am the original owner as well)
Original Transmission (Rebuilt once at 278,000 miles)
ECM has not been replaced since it went out of warranty

It was running with no problems up until Saturday, of course I wasn't at home. I started it and it turned over and started instantly. I was going to put it in reverse and it died. I tried it again and it just cranked and cranked with no firing at all. I hauled it home and checked out this message board.

Parts I have replaced since it stopped running.
Oil Pressure Switch
Distributor Cap and Rotor
Fuel Pressure Regulator diaphram (It was spurting gas through the vacuum tube when it was disconnected and cranking)

Things I have tested since it stopped running.
Fuel Pressure at the rail - 45psi after 2 second priming, around 43 psi while cranking
I have spark at first spark plug
For the first injector on the driver's side, I have 11.75v with KOEO
I bought a NOID test kit and checked the first two injectors on the driver's side and the light flashed while I was cranking the engine
The NOID kit also had a IAC tester and I plugged that in and when I cranked it over a red and a green light came on.

A little over a year ago, I had to haul it home because one of the small wires in the key cylinder sheered off. I bypassed this with resistors under the dash and it has run well for the last 10,000 miles.

When I turn the key on now, the security light does not come on at all. I believe I replaced all of the dash lights a little over a year ago so I don't think it is burned out, but I am not positive.

When I turn the key on, the fuel pump primes for 2 seconds or so and stops. When I crank the engine, the oil pressure starts out at zero and then begins to climp up to around 30psi. When I stop cranking, the fuel pump runs until the oil pressure gauge returns to zero. This happens even if I turn the key off and remove it.

Any help would be greatly appreciated.

 

I just swapped the security light bulb for the seat belt one and still no securty light when I turn the key to the run position.
Does this point to the VATS module itself?

 

Sounds like it's getting fuel, so I would start looking for something electrical. You may need to check all the plug wires. If it was VATS I don't believe it would turn over at all.

 

I will try to check out the other plugs and injector connections tomorrow.

The Security light used to come on for a few seconds and then turn off once the proper resistance was detected which is why I was wondering about the VATS. When I had to bypass the key with a resistor pack, the security light just stayed on and then I had no cranking or anything.

 

plugs wet with gas?,will it fire if you shoot some gas or
either into the throttle body and crank? also check
timing as chain might have got loose and jumped with
that many miles.

 

The Thread link I'm posting here has 4 different cars, with 4 diff problems, with 4 diff fixes. TONS and TONS of great info on here!
https://www.thirdgen.org/forums/tech...art-story.html

 

I had a similar problem with my 88 GTA LB9. Check all of the wires and connectors on and around the ignition coil. There are two pigtails that plug into the top of the coil. One of them goes to the distributor. These wires tend to get hard and break. This was the case with my car. Be sure to check them very carefully because the break in mine was really hard to see. I would also take all of the connectors off to check for water or corrosion. Good luck.

 

i would say something is up with your vats but if not have autozone test your ignition control module

 

When my VATS system was messed up, the engine didn't (and shouldn't) have cranked at all, since the VATS system is what enables the starter enable relay. Assuming that you checked everything correctly, you are probaby losing compression. Check compression for valid and consistant values at all cylinders. Make sure your spark plugs are good n tight first. For some reason #8 spark plug works it way loose every few months on my engine. Also check to see if you have oil in your coolant (and vice versa). My guess is that you have a blown head gasket. Thats just a guess from what you posted here, so check before you assume and start pulling heads off.

 

I pulled the gauges again and found one of the connectors for the security light was not making contact. Fixed that and the security light now acts as it should. I checked all of the injector wires and they are all pulsing properly. I am now going to replace the timing chain and sprockets. They will be in tomorrow but I have to run out and get a puller for the harmonic balancer.

Unless the timing chain was replaced while under warranty (probably not), the cover has never even been off. Suprisingly, the pulley for the harmonic balancer came right off and all of the bolts for the timing cover that I could get at loosened up easily.

Any suggestions of other things I should look at while I have all this off in the front?

BTW, Thanks for all the help so far. Should have said that much earlier. Apparently, my manners are not what they should be.

 

when going back together,make sure the crank sprocket
is fully seated against the crank and the harmonic
balancer is fully seated against the sprocket-if the aren't
the sprocket may start to"work"on the crank and wear
that area Also best not to use a hammer to install the
harmonic balancer,use install tool or longer bolt to draw
it on

 

ericnelsen,
It's a ton of info., but y84pauloflondon is right. Check out that thread...it lead to the eventual "cure" for my camaro.
Check the resistance on each injector. (With your OHM meter on the lowest setting) The injectors should read above 10. Since I've replaced my injectors, I haven't had any problems.

Hope this helps you out!

 

"A little over a year ago, I had to haul it home because one of the small wires in the key cylinder sheered off. I bypassed this with resistors under the dash."

Please, for the love of GOD, explain to me exactly how you accomplished this. The dealership says I can't get a new VATS box for my '90.
I also sheared and shorted a wire when my tilt steering pins failed, had it towed home, and there it sits. thanx in adv.

 

I realize there are other threads that describe this procedure such as the following:

https://www.thirdgen.org/forums/elec...tor-value.html

but here is what I did.

In the steering column there are two small white wires in an orange casing. I clipped the unbroken white wire near the key cylinder and pulled both wires down under the dash. I measured the resistor in my key with a multi-meter and matched it up to one of the ranges in the following table that I found at this site.

http://tpiparts.net/vehicle_anti_theft_system__vats_/

There are 15 possible resistance values that were used by GM.
402 ohms (acceptable range 386-438)
523 ohms (acceptable range 502-564)
681 ohms (acceptable range 650-728)
887 ohms (acceptable range 850-942)
1130 ohms (acceptable range 1085-1195)
1470 ohms (acceptable range 1411-1549)
1870 ohms (acceptable range 1795-1965)
2370 ohms (acceptable range 2275-2485)
3010 ohms (acceptable range 2890-3150)
3740 ohms (acceptable range 3590-3910)
4750 ohms (acceptable range 4560-4960)
6040 ohms (acceptable range 5798-6302)
7500 ohms (acceptable range 7200-7820)
9530 ohms (acceptable range 9149-9931)
11800 ohms (acceptable range 11328-12292)

I purchased resistors from RadioShack to match the value I found from my key, soldered them together and measured the combined resistance to make sure it fell within the range stated above. I soldered one end of the resistor pack to one of the wires I removed from the steering column, slid a shrink tube over this and soldered the other end to the remaining wire. I wrapped it all up, tied it off under the dash and that was it.

Hope this helps.

Eric

 

thank you. if this works, you just made my Christmas Card list, my friend.

 

Wholy Crap. dip me in mustard, and call me hotdog... IT WORKED!
thank you !!!!

 

OK...
I am finally back and it is running again.

I replaced the timing chain and gears since they were original and it looked like the chain had indeed jumped. It was pretty sloppy. I was able to get the timing cover off, but I had to drop the oil pan to get it back on. What joy! :-(
Remove the distributor cap to prevent it from running into the firewall. Removed the through bolt from the motor mount, jacked the engine and put blocks of wood between the motor mount and the engine bracket. Since I had to drop the oil pan anyway, I decided to replace the oil pump since it didn't seem to have the pressure it used to, though it was difficult to tell since it wasn't actually running. While removing the old pump, the nylon connector that holds the shaft onto the oil pump snapped so I had to go get the part. Forty-mile round trip for a 99 cent part. Ouch! I also put on a new harmonic balancer, since the old one looked pretty tough.
I put it all back together and still a no go. It sounded like it wanted to start now, but couldn't.
Someone here suggested checking the compression on the cylinders and here is what I found.

Cyl Dry Wet
1 90 120
3 120 150
5 120
7 120
2 15 30
4 110
6 120
8 120

Yes, that was 15 on cylinder number 1. I did not check all of the cylinders wet since I needed to pull the heads anyway. Fortunately the exhaust manifolds had been off in the last few years and so went well. The heads were a challenge to remove since the metal gaskets chose to stick to the heads in spots and to the block in others.
I took them to Tesar Engineering in Long Lake, MN and they said that it looked like some chunks of carbon had come loose and got stuck under the valves preventing a good seal. They cleaned them up, drilled out two broken bolts from my initial removal of the exhaust manifolds and I picked them up. Nick, a friend of mine came over to help install them. I purchased new head bolts and as luck would have it, one of them broke off while we were doing the second round of torquing. Of course it was on the crowded passenger side of the engine. We installed the one on the drivers side with no problems. The next day, we drilled it out and replaced all of the bolts with a new set. Basically, everything went back together smoothly, except of course a few times when I installed some pieces in the wrong order and had to back up a try again.
I replaced the ignition coil and the fuel filter and you guessed it. It started!!!!!

I adjusted the timing a bit and just smoothed it out, hopefully I can talk Nick into coming back to check the timing.

Thanks to all of you for your advice and suggestions. Not just on this thread, but on all of the ones I read through.

Eric

 

One more note...
The carbon chunks in cylinder 1, I assume, came from a couple of years ago when the injector was stuck open for quite a while. That cylinder, by far, looked the worst.