crowz

If your fuel pressure gauge is working right and showing nothing it kind of has to be the regulator or the pump but you changed the pump already so that leaves the regulator.

Though Ive never seen a bad regulator read 0 psi. That's usually the pump.

C4SS

One more thought; I've owned and driven this '88 for
over 7 yrs.; It has the org. security system, but it worked
erratically, so I disconnected the horn. I know it works
in relation with the doors, but does it also have the ability
to shut the engine down?
Is there a reset button or procedure?

crowz

Factory security measures will keep it from running at all.

Aftermarket? Who knows.

Cliff Harris

The only thing it does is honk the horn if the door is opened while it's armed.

crowz

I was thinking about the key chip not the door opening part. But that makes sense.

J H

Did you put the "heat grease" under the ignition module? Without that, the module will overheat rather quickly.

C4SS

I did some internet searching of 1988 GM security system reset,
and found some very interesting facts about GM's TDM; theft
deterrent module. Says the life span of the system of chip is
maybe about 6-10 yrs. One of the symptoms is the engine only
runs 1-5 sec. It can be set off by changing out of various parts.
There is also a youtube video showing how to repair the system
to fit a worn key chip. Measuring of ohms of the key chip, buying
resisters that match that amount, and putting them inline of a
certain orange wire under dash that goes to ignition. Cheap.
For GM to replace components, $700. +
Anyone familiar with this solution? Sound Plausible?

If so, I need to know where and how to find that orange wire.

crowz

If the chips not being read right or the system isn't working it wont crank to start with so no that's not your problem.

C4SS

One of the TDM results, is stated that it will only run 1-6 seconds.

Do you know of a reset of the system, once tripped?

crowz

The chip went bad on one of the keys for my 86 coupe. Wouldn't crank period. Was like the starter was dead from what I remember but it has been years ago. Same with several Camaro and other fbodies I fixed for people around here. Bad chip or vats problems = no start. Ive never seen one run at all with a bad chip or vats problems.

If someone else has they can chime in. Wish the car was closer Im sure I could fix it in 5 minutes if I could get my hands on it.

J H

When you are in a no-start situation, are you getting fire to the plugs?

crowz

From what he says he never has a "no start" problem. Its starts fine just runs a few seconds and then quits.

Cliff Harris

The VATS system replaced the TDS system as far as starting and running goes. As far as I know the TDS only controls the starter enable relay. I don't think it has anything to do with the running of the engine.

You reset the TDS system by unlocking the door. You set it by locking the door. After 1985 the only thing the TDS system does is honk the horn if the door is opened without disarming the system.

If VATS is not disabled the engine will not crank (assuming the starter enable relay hasn't been bypassed). If VATS is not disabled the injectors will not pulse and you will get an error code 46. The engine will not run at all. The ECM only does the VATS check when the ignition is first turned on, so it is not possible for VATS to kill a running engine. I have heard that is later years (like 1994 or so) that VATS CAN kill a running engine. Doesn't seem very useful...

C4SS

Thanks for all the help. I'm pulling the fuel regulator tomorrow, the new one is not
stocked, nor are the rebuild kits. What's the best way to go? Will I be able to tell
by removing it if it's bad? or by opening? I'm guessing that if bad, there will be fuel
on both sides of diaphragm? Or a broken spring?

One curious thing, when using my wife's key, it'll will run a few sec. longer.

Removed, and photographed, if it helps any. Don't see thing torn
and the spring valve works freely.

Also found vacuum lines missing from junction where Fuel reg.
vacuum line goes to. Could that be my problem?
There seems to be many changed or deleted parts on this car.
They were that way when I got it, and has worked fine for 7yrs.

woodstock

Did he ever find the problem?
edit:
Probably gave himself the bullet, no activity since

pecosbilly

I had to remove the Schrader valve from fuel rail in order for my fuel pressure gauge to read the pressure. My problem similar, but I've 45+ lbs fuel when engine starts. Will run with 2 injectors unplugged (electric plug) but quits running when those are reconnected. New fuel pump really wasn't necessary, it had the same pressure before, but had been replaced in 01, thought it was time for a new one. Hose from pump to pickup line was shot, so it was overdue to be replaced anyway. Why would it run on 6 but not on 8?? Call me stumped!

pecosbilly

More on my 87 with start but quits after a few seconds...Does the 87 have such a security system? If the key chip is the original and causes the engine to shut down, would it still run on 6? Some sort of "limp mode" Incase the chip failed you could still get to a garage for service?

pecosbilly

So I need to watch that YouTube video myself and find that orange wire? TDM used on my 87?

woody41

My 91 did the same thing I replaced the same parts, issue ended up being one collapsed cat and one clogged cat. Had the system replaced with a single high flow cat. No issues since runs great with all the new sensors, fuel pump, injectors, ignition, etc. A Corvette shop did a flow check on the exhaust system and found the issue. Worth a try....

aklim

Nope. It won't crank and won't allow you to crank if the VATS system is not sending the right info. I taped up mine on the key and it pressurizes the fuel rail but will not crank nor will it allow you to crank for a few minutes after that "failure"