Fiero stopped running suddenly. (Page 1/3)
iboesen APR 08, 07:44 PM
Hello all,

So I have been doing some research on this topic and think I may have pinpointed the issue but I am not sure.
I was driving my 87 Gt yesterday and all the sudden my engine started sputtering and then died. I pulled over and tried to start it, it was crank over fine, then start up for a little bit (maybe 3 seconds) then sputter and die. I dont believe it to be electrical since it the car will fire and run for a little while before dying. My guess is that it is the fuel pump?
When I start that car I can hear the fuel pump for 2 seconds and then when I start it I get the same thing. Starts, sputters dies. I was not sure if it was a bad fuel pump relay to I tried plugging it into the AC Relay and got the same result.

Is this a sign of a bad fuel pump or something else? Today it ran for 10 seconds then sputtered and died. (By the way the fuel tank is full)

Thanks for the help
Gall757 APR 08, 09:09 PM
Welcome to the Forum!

You need to check the fuel pressure. Let us know if you need help with that. If the pressure is OK, the next thing to check is the ICM.
iboesen APR 08, 09:39 PM
Thanks!

I will go ahead and try that. I will let you know what I find. Any quick tips for checking the fuel pressure?
Dennis LaGrua APR 09, 05:15 PM

quote
Originally posted by iboesen:

Thanks!

I will go ahead and try that. I will let you know what I find. Any quick tips for checking the fuel pressure?


Its like taking tire pressure but you'll need a fuel pressure gauge that screws on the fuel rail at the schrader valve fitting. You should have around 43 psi. with the key on. if you have fuel pressure then check for spark. The most common problem is usually fuel or spark. Also check for trouble codes.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

iboesen APR 09, 08:36 PM
So I went to my local harbor freight and picked up a fuel pressure gauge and followed the instructions of a youtube video. Checked the fuel pressure on the schrader valve on the fuel rail.

I recorded what I got with my Fiero, here is a link the the video I just took.
Here is a link
Here" TARGET=_blank>https://youtu.be/_PYLDGQLg5UHere

As you can see I am getting about 44psi when primed then then it goes to about 38 when the car is running. Just before it dies.
Is this okay? Could it be a fuel filter issue?

Next step is the ICM?
Patrick APR 09, 08:59 PM

quote
Originally posted by iboesen:





You appear to have one heck of an exhaust leak. Sounds like a cracked exhaust manifold or two.

IMO your fuel pressure is dropping too fast when power to the fuel pump is cut.

[This message has been edited by Patrick (edited 04-09-2019).]

iboesen APR 09, 09:17 PM
Do you think I have a bad fuel pump?
Patrick APR 09, 11:14 PM

quote
Originally posted by iboesen:

Do you think I have a bad fuel pump?



No, but you might have a leaking injector (or two or more)... and/or the short length of hose inside the gas tank may be starting to rot.

The drop in fuel pressure might not necessarily be the cause of the engine now not starting... unless the plugs are getting soaked from leaking injectors. Pull the three "easy" plugs (for now) and have a look at them. See if they're crudded up.

[This message has been edited by Patrick (edited 04-09-2019).]

iboesen APR 10, 12:20 AM
I will check back with you guys this Thursday and let you know what I find. If anyone has any other suggestions I’d be happy to try those as well. Just trying to get this figured out so I can take her out this weekend.
85 SE VIN 9 APR 10, 07:45 PM
Does your tach work when cranking? Could be your module. Very common problem.