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Fiero wont start

Printed From: West Coast Fieros
Category: Technical Topics Forum
Forum Name: Technical Questions and Discussions
Forum Description: Got a technical question about your fiero? ask it here.
URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=2823
Printed Date: 22 November 2024 at 10:58pm
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Topic: Fiero wont start

Posted By: killscreen123
Subject: Fiero wont start
Date Posted: 08 February 2012 at 8:39pm

Hello Everyone,

I just had a quick question, my father's 85 Gt im
working on wont start. The fuel pump wasn't running, so I
replaced it and the tank. I now have a working pump, but
it still wont start, just keeps cranking and cranking.
When i squirt fuel into the Throttle Body the engine
starts and runs until I stop squirting fuel in it, the
spark plugs have a spark as well. What could be the
problem?

Thank you for your time

Replies:

Posted By: Capt Fiero
Date Posted: 08 February 2012 at 8:45pm

When you first hit the key do you hear the pump fire up? If not the first thing to do is replace the fuel pump relay. Its just behind the air filter box. If the car is an A/C car, you can swap the fuel pump relay and the A/C relay to test. They are right next to each other.

If you DO hear the pump but the car won't run without spray, then replace the fuel filter.

Next up check the fuse's. There are 2 fuses for the V6 fuel injection. Its dumb but true. Its a batch fire system, but there are 2 fuses one for the left bank and one for the right bank.

After that, if it still won't start, you got me.

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Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.

Posted By: killscreen123
Date Posted: 08 February 2012 at 8:48pm

Hey Capt,

The pump does fire up i can hear it. The car has been
sitting for maybe 10 years, do you think the fuel filter
could be so clogged and screwed that barely any fuel could
be pumped through?

I never thought to replace the filter I'll have to take a
look at it soon.

Posted By: Capt Fiero
Date Posted: 08 February 2012 at 8:58pm

Yes that filter can be plugged solid with crap in the bottom of the tank from sitting that long.

You did not mention that the car had sat that long. It is very possible that the injectors are seized up. The 85's used needle type pintels. Imaging something the size of a sewing needle that needs to spray the fuel. It can become plugged even with regular day to day use, let alone sitting for that long.

I'll warn ya know, the last time I priced a new set of injectors, it was in the Two Thousand dollar range. I typed that out just so you know it was not a typo. However used injectors / rebuilt ones are only $200-$300 for a set of 6.

P.S. the fuel filter is under the car, on the bottom kinda in between where the base of the passenger seat is and below the battery. Its a large silver can with 2 threaded pipe fittings going into it.

-------------
Capt Fiero
88 Fiero GT 5spd V6
Eight Fifty Seven GT V8 5spd.

Posted By: CFoss
Date Posted: 09 February 2012 at 10:31am

Obviously a fuel issue. The best thing you can do is go down and get a fuel pressure guage from where ever for about $50 (I have a cdn tire one, works fine). It'll tie into a schrader port on the fuel rail on the passenger side, under a cap.

Assuming your pressure is ok (30+ should start fine), and the fuses are ok, break and check for +12V at the injector harness connector if you can get to it. I can get at mine, but my intake is non stock.

If all checks out there, the issue is on the ecm side, or all you injectors are plugged (unlikely). It could either be the ecm itself, or the ecm's ground. Has the ecm been messed with??

I really suspect a fuel pressure issue (Good advice to look at the filter), because even when my injectors weren't working, the start injector provided enough fuel to fire the engine for 1 second or so. There is no ecm control of this injector, which points back to fuel pressure issues.

Chay

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86 SE 3.4