1992 starting issues
I picked up a 1992 6 speed coupe off a member in here a few weeks ago. I knew it didn't run and the owner just wanted it gone. I can't blame him for all the issues it has given him.
First things first, I replaced the dead battery. What else did I find? Well, the computer rattled and I pulled the cover off the back and a Hypertec chip was installed but not fully pressed in. I also noticed the stock chip was inside rattling around. Took the hyperjunk out and replaced it with the stocker. I found a plug wire not connected and two other plug wires swapped! I jumped the pins and turned the key on and saw a single code, H74. Looks like from the radio replacement they fugged something up???
When I turned the key the fuel pump primes so I figured I would pull the jumper and try to fire it up. Low and behold it fired! It revved to about 1200 RPM and died. Hrm... With the paperwork in the folder the prior owner gave me I found that the fuel filter was changed some 13 years ago and 20k+ miles. I changed that and primed the system a few times and BAM! It fired and ran for about 10 seconds and died. It fires to about 1500 rpms and the idle had come down to about 900 and was smoothing out before it died. I tried to start it again to no avail. A tad of starting fluid saw the thing start again but died. I am not one to use a lot of starting fluid but it will run on it. Issue is this, if you try to modulate the throttle at all the pedal kicks back as if the ASR is activated. So while cranking it over I turned the ASR off and it fired up but died again within a moment. Each time oil pressure would shoot up to about 40-60, so I believe the sending hnit is functioning correctly. I also would say the relay is working for the fuel pump as it primes when you turn the key. It stays on for about 2-3 seconds each time. I did notice that once in a while after I try to start it the pump will reprime the system if I turn the key back to the "ON" position from the "Start" position. Other times it won't reprime. A few times I tried to see if the pump would prime the system 3 or 4 times in a row and a few times it wouldn't. Not sure if either of those are related to a bad pump or not.
Having searched, a lot, I have seen multiple issues that sort of fit this. As I ran out of time yesterday (I have a 4 month old) I will get back in the garage tonight and do a fuel pressure test. Also planning to test a NOID Light and check for pulsing, but my gut is that they are not.
As I am of the position that if it ain't broke don't fix it, I still am going to swap out some little things that cause issues. The car is reaching its golden age and for piece of mind I plan to replace some smaller dollar items such as the TPS and COIL. Even thinking the ICM might have something to do with this.
From what I gather the VATS system is not the issue because the starter engages and the fuel pump primes, and well, it has started on its own a few times.
Here is a rundown of what the prior owner had done.
New fuel pump, new injectors, new opti spark, new water pump, remanufactured ECM, new plugs, new wires (I found one that the casing has a small rip, though not down to the wiring), and they traced all the grounds.
So yeah, I am knee deep in this car but I believe it's an issue that can be resloved if I am persistent.
Any help/advice is greatly appreciated. I am not too far from Tampa, FL so if anyone ever wants to lend a hand in person, I would not object. I usually pay with food and perhaps an adult beverage or two.

I am accountant by trade so please, be gentle if I am messing something up or not on the correct path.
Last edited by TLS_Addict; Jul 28, 2015 at 08:24 AM.
I will pull the vacuum from the regulator and smell for fuel. What is a bad sign, if I smell or do not smell fuel? I will hook up the fuel pressure tester tonight and cross my fingers.
Thanks for your help. Can't thank you guys enough.
Last edited by TLS_Addict; Jul 28, 2015 at 08:25 AM.
After 2 minutes it dropped to 38 psi.
After 5 minutes it dropped to 35 psi.
After 10 minutes it dropped to 32 psi.
When trying to start the car fuel pressure goes to 42 psi and the car fires and the pressure drops to under 35 psi and the car dies.
I pulled the vacuum hose on the fuel pressure regulator and sure enough I smell gas in the vacuum line.
So a fuel pressure regulator is on the agenda for tomorrow night.
Does it sound like I am on the right track?
After 2 minutes it dropped to 38 psi.
After 5 minutes it dropped to 35 psi.
After 10 minutes it dropped to 32 psi.
When trying to start the car fuel pressure goes to 42 psi and the car fires and the pressure drops to under 35 psi and the car dies.
I pulled the vacuum hose on the fuel pressure regulator and sure enough I smell gas in the vacuum line.
So a fuel pressure regulator is on the agenda for tomorrow night.
Does it sound like I am on the right track?
Last edited by antfarmer2; Jul 27, 2015 at 10:49 PM.
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I am in luck, my father has a 93 with a spare (new) computer back in PA. I'm sure I can get that from him.
My top is cracked, maybe I can take the other glass top he has. Yes, he has two. He does that stuff. Lll
One thing, the H74 shows up in the code 1 when it pops up, in all the other numbers (4 & 9????) There are just three hashes.
Since the H denotes a history cods, wouldn't that keep the C12 from showing? Just typing what I am thinking. I also am thinking of cheese cake.....with cherries, and maybe some chocolate sauce, and perhaps a beer, and Dallas Cowboy cheerleaders.
One thing, the H74 shows up in the code 1 when it pops up, in all the other numbers (4 & 9????) There are just three hashes.
Since the H denotes a history cods, wouldn't that keep the C12 from showing? Just typing what I am thinking. I also am thinking of cheese cake.....with cherries, and maybe some chocolate sauce, and perhaps a beer, and Dallas Cowboy cheerleaders.
your fpr is bad if your sniffing gas.
Happy for you,
Lee
I was thinking ICM. I have a coil ready to go on as well if it seems to have a spark issue.
The thing.is, this one fires just fine and starts but dies. Verified fuel pressure and a faulty FPR.




The diaphram has a hole in it and sucking the gas in the vaccume system instead of regulating the pressure


