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Old 04-06-2011, 10:24 PM
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TBI problems

I'm new here and I dont know too much about about fuel injection but I'm in the process of getting an 88 firebird with a tbi 350 and it wont start. The owner says he hit some ice slid sideways then hit a dry spot and it jerked the car. When it jerked the car died and wouldnt start, he says he has replaced the fuel pump and now its getting fuel to the tbi but nothing is coming out the injectors. Would that just be injectors?
Old 04-06-2011, 10:40 PM
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Re: TBI problems

doubtful its the injectors themselves. Check to see if you have power to them.
Old 04-06-2011, 10:57 PM
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Re: TBI problems

I'll give that a shot
Old 04-08-2011, 02:58 PM
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Re: TBI problems

All the wires/connectors are good, they have good power to them
Old 04-08-2011, 03:14 PM
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Re: TBI problems

First - so you know ... no 3rd gen car was offered with a 350 TBI - they were all 305 TBI cars. So - if it's really a 350, it's been swapped in. You'll have to get the block ID numbers off the engine block to verify.

IF it is in fact a 350 TBI - then there would have to be a 350 computer chip installed, as well as a 350 knock sensor, and 350 fuel injectors in the TB in order for it to run decent at all. So, if the seller is insisting it's a 350, better get confirmation that all these things have been upgraded when the 350 was swapped in.

IF it has a 350 that was swapped in, along with a 350 prom, and that prom is a 1989 or later chip - has the VATS been bypassed in the chip (or rather has a bypass module been wired into the ECM)? VATS disables injector firing - maybe if there's a VATS bypass module installed for that 350TBI chip a wire came loose.

OK - assuming it's a 305 factory car ...

1) Are we 100% sure it's a 1988, and not a 1989. Get the production date off the drivers door sticker. 1989 has VATS - again - VATS disables the injectors in the chip itself. Does the key have a pellet in it?

2) Was fuel filter replaced? Maybe it's clogged.

3) I assume the starter turns, but the car won't fire right? What about if you spray carb cleaner in the TB - will it fire then?
Old 04-08-2011, 09:48 PM
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Re: TBI problems

He said it was a 350 crate motor put in a couple years back it is an 88, it was a 305 and the fuel filter and pump were replaced. I never asked him about the computer. Yes it does start as long as ur spraying carb cleaner/starting fluid into the tb
Old 04-09-2011, 03:55 PM
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Re: TBI problems

Originally Posted by ROADKILL76
The owner says he hit some ice slid sideways then hit a dry spot and it jerked the car. When it jerked the car died and wouldnt start
Inertia switch???
Old 04-09-2011, 05:56 PM
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Re: TBI problems

These cars dont have intertia switches..well if they do I never knew about it.

Original poster. You will have to check injector pulse. If no injector pulse could be a vats problem. more likely failed ignition control module.
Old 04-09-2011, 06:27 PM
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Re: TBI problems

I thought 88s didn't have VATS, would the ignition control module stop the injectors from pulsating?
Old 04-09-2011, 08:56 PM
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Re: TBI problems

1988 shouldn't have VATS. But like I said - IF a 350 chip was installed due to the 350 swap, and it's a VATS chip, and wasn't properly bypassed, then that would stop injector pulse.

Ignition module has nothing to do with injector pulse.

You really need to find out EXACTLY what you have, and what's been modded and changed, and exactly how, in order to be able to solve this and other issues in the future. You need specific details from the previous owner on the swap, what was added, what was done, etc. or your going to have endless unanswerable problems (since you and thus we don't know exactly what you have).

Like I said - if a 350 TBI was swapped in, there would have to be a 350 TBI chip, a 350 TBI knock sensor, and 350 TBI injectors at a minimum. You need to know what year 350TBI chip was used to start with.

You also should get a block ID off the block itself, and make sure it's a 350 - sellers lie about 350's all the time with these cars, either to get more cash, or because they just don't really know better themselves.
Old 05-11-2011, 03:09 PM
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Re: TBI problems

Ok so I just got the car home last night so now I can work on it more often but replaced the ignition control module just to see if it'd change but nothing different. No power to the injectors at all. It has spliced wires going to the tps sensor for some reason. The computer wasn't bolted down anywhere, it was just hanging by the wires under the kick panel.
Old 05-12-2011, 01:21 AM
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Car: 1988 T/A
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Re: TBI problems

I was told its most likely the computer?
Old 05-12-2011, 04:33 AM
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Re: TBI problems

Probably everything is working, but someone did a garbage hack job engine swap.

You can try to put all the wires back, as it came from the factory, this makes diagnosing alot easier.
Old 05-12-2011, 09:41 AM
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Re: TBI problems

Are all 4 wires to the injectors supposed to have power? I didn't have the ignition on earlier
Old 05-12-2011, 10:25 PM
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Re: TBI problems

That dirty lil mother######......its a 305
Old 05-13-2011, 01:00 AM
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Re: TBI problems

did you see the 5.0 casted on the back of the block or something?
Old 05-13-2011, 01:15 AM
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Re: TBI problems

No the serial # on the front and it has the 305 heads
Old 05-13-2011, 04:17 AM
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Re: TBI problems

What casting # heads?
Old 05-13-2011, 05:31 AM
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Re: TBI problems

mine done that one day . i have a 92 .i unhooked the fuel line to the tbi an made sure the fuel pump was working an after i hooked it back up it fired right up .mine got vapor locked somehow ,it's worth a try
Old 05-13-2011, 10:04 AM
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Re: TBI problems

Yea that was one of the first things I tried. I didn't check the casting # on the head they're high rail heads and instead of having the normal 2 post design on the side, which would make it a 350, it has a triangle, which is a 305. The little things you learn when you work at a machine shop are awesome.
Old 05-13-2011, 10:50 AM
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Re: TBI problems

Well hell machine up a 350 for that sucker!
Old 05-13-2011, 03:31 PM
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Re: TBI problems

I will be but in the mean time I still need to get the car going
Old 05-13-2011, 11:57 PM
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Re: TBI problems

I grounded the injectors while cranking it over and they fired very well
Old 06-18-2011, 06:27 AM
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Re: TBI problems

Were you ever able to fix the problem? I'm having somewhat the same issue.
Old 06-18-2011, 01:29 PM
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Re: TBI problems

i had to replace computer when I had same symptoms.
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