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Getting Irritated

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Old Sep 29, 2006 | 12:13 AM
  #1  
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TPI
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Getting Irritated

Hey Guys,

In the Electronics forum.. Ive had 2 threads going on
about a faulty fuel pump and trying to trouble shoot it.

Ive finally solved the issue, the pump primes and operates
normally, however the engine doesnt anymore. I havent done
anything to the engine, I havent touched a single thing..

The motor fires up Immediately, hesistates.. runs sluggishly
and when I try to give it gas.. It dies.

When I dont touch the gas, the motor flucuates for a
a few moments, then dies out shortly afterward.

I searched here for some similar threads, thinking its
a bad ICM.. but how? The motor is cold, and the car
hasnt ran on the road in 2 weeks + ..The motor basically
runs with a mind of its own after I turn the key, if I touch
the gas, it chokes it.. and all after the fuel pump swap.

I have fuel pressure, and I have spark.. Injector fuses are
good, grounds are good.. TPS is normal

The only thing I dont know is if the fuel pump keeps the
fuel pressure at 40+ PSI after start-up, I need a gauge..

If it doesnt, What would cause this?

.. or Does this sound like a ICM or ECM problem?

Last edited by TPI; Sep 29, 2006 at 12:16 AM.
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Old Sep 29, 2006 | 12:30 AM
  #2  
DENN_SHAH's Avatar
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From: houston
Car: 83 POS monte carlo 2015 chevy P/U
Engine: 92 5.7 tpi 5.3
Transmission: 700r4 6L60E
Axle/Gears: 2.42 too high
they may have given you the wrong pump. i have seen TBI pumps dead head 25+ PSI.
a TBI pump looks just like a TPI pump.

at around 20~25 PSI a TPI motor will start & run, but it will run poorly.
much more than a light touch on the gas petal & it dies, sometimes it will backfire some & then die.
get a pressure gage on it & see what it is & then post back.
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Old Sep 29, 2006 | 01:27 AM
  #3  
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TPI
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Wow, That could seriously be the problem

I will grab a pressure tester tommarow, It has fuel at the rail (I got blasted in the eye checking the schraeder valve, haha)

I just dont know how much it has on it.. and
25PSI will sure make a TPI motor puff and fart ..
or barely run at all!!


Thanks for the heads-up!

Last edited by TPI; Oct 2, 2006 at 03:24 PM.
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Old Sep 29, 2006 | 10:35 AM
  #4  
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From: New Hampshire
Car: 86 MCSS-87 Z28
Transmission: Auto OD-5spd
Axle/Gears: 3.73 both cars
Try replacing your fuel filter. Sounds like the problem. You will get 40lbs at start, then pressure will slowly drop and you won't be able to rev and it will die.
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Old Oct 2, 2006 | 03:28 PM
  #5  
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TPI
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
Originally Posted by DENN_SHAH
they may have given you the wrong pump. i have seen TBI pumps dead head 25+ PSI.
a TBI pump looks just like a TPI pump.

at around 20~25 PSI a TPI motor will start & run, but it will run poorly.
much more than a light touch on the gas petal & it dies, sometimes it will backfire some & then die.
get a pressure gage on it & see what it is & then post back.

Sorry for the Delay.. Work tends to take ahold of you

Denn-Shah hit the nail right on the head, I called up the part store and confirmed the PSI rating of my pump without a pressure guage.. I now have
18-25 PSI rated fuel pump in my TPI car, haha

Its not entirely my friends fault for buying
the wrong one, I should have went with him
to ensure I got the correct pump.

Anyway, thanks Denn for the Heads up.. Ill be
up and running in a day or two
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Old Oct 4, 2006 | 02:34 PM
  #6  
D's89IROCZ's Avatar
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From: Ontario, Canada
Car: 1989 IROC-Z
Engine: 5.7L EFI LTR setup
Transmission: T-5 World Class
I had one bad injector do that to me. I could get it too run ( with some peddle) then it would barely hold an idle . Any throttle input and the car would die.

Just to toss in a guess........ good luck man !
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Old Oct 4, 2006 | 03:55 PM
  #7  
MikeH's Avatar
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From: Fla
Car: 90 IROC
Engine: 406
Transmission: GMPP 93/4L60
Axle/Gears: 9 bolt 3.27
Thats sucks glad you figured it out though.

I helped my brother replace the pump in his blazer. we couldnt figure out why the gauge didnt read right after. Found out later they gave us the wrong pump. Everything pluged in and looked right too.
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Old Oct 7, 2006 | 12:47 PM
  #8  
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TPI
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Joined: Aug 2004
Posts: 1,214
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From: Norwich, CT
Car: '89 Trans AM/'88 GTA
Engine: (2) Tuned Port L98's
I happened to exchange, replace and install
the right pump with the wrong one.. I got a
rated 50psi+ electric in-tank with a nice
warranty.. and boy! Does my car purr like
a kitten

I dont know if my old pump was slowly going
to die or what, But one thing for certain.. My
car didnt idle/run/drive the way I have
remembered it..

She idled/ran 4x times better than I remember!!
So all and all after the heartache and trouble,
..the car rewards me

Again, Thanks for all the input gentlemen

Last edited by TPI; Oct 7, 2006 at 12:50 PM.
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