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TPI 350 cutting out at 3500 - 4000 RPM??

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Old Apr 2, 2005 | 03:19 PM
  #1  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
TPI 350 cutting out at 3500 - 4000 RPM??

Long story short, my Camaro is having some issues. When you get on it, it cuts out at 3500-4000 rpm. Sometimes it will rev up to 4500-5000 but if it starts to cut out, you can hear a pining (not timing) in the exhaust. I have headers, cat back exhaust, K&N filters, and Accel 24lbs fuel injectors. The car has been doing this before most of the mods, does anyone have an idea on what this could be?
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Old Apr 2, 2005 | 04:05 PM
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
I think its your fuel pump. My car had the same problem. I'd get on it, and if the thing was at operating temp...it would hit 3500-4000 in first and bog and act like it was going to die until I let off and let it shift. I originally thought it was the tranny, but thats because I was green still. I say check your fuel pressure under load. If your car can redline when its cold and the engine is still under 120 or so, and then when it gets hot it begins to cut out, I'd say your fuel pump is on its way out. You also may want to check your fuel filter.
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Old Apr 2, 2005 | 05:15 PM
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
I just replaced the fuel filter cause I thought that might be it. How hard is it to replace the fuel pump? I have heard that once you break the factory seal on the tank they never quite seal right again, any truth to this? Also any fuel pumps you would recommend like Holley or Venom?
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Old Apr 2, 2005 | 05:19 PM
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
Don't know anything really about that not sealing right crap and all that. All I know is that you have to remove your muffler, drain the tank, drop the tank, and the fuel pump is on top. I replaced mine with a stock one from GM. I've heard that the stock ones are fine unless you're pushing upwards of 400 hp, which I'm not nor do I plan to.
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Old Apr 2, 2005 | 05:26 PM
  #5  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
How much did the GM fuel pump cost?
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Old Apr 2, 2005 | 05:32 PM
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
Don't remember really. Something along the lines of 125-150.
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Old Apr 3, 2005 | 12:41 AM
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hey if you figure this out let me know I have the same prob on my new 383 in my vette.
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Old Apr 3, 2005 | 12:56 AM
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From: Salem, NH
Car: 1999 Z28
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23 10 Bolt
plugs, wires, cap, rotor, or coil.
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Old Apr 3, 2005 | 12:57 AM
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
I still say check your fuel pressure. If it drops under load under operating temp...your fuel pump is taking a crap.
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Old Apr 3, 2005 | 07:29 AM
  #10  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
Originally posted by SLP IROC-Z
plugs, wires, cap, rotor, or coil.
All brand new stuff. Using Accel 8.8 wires and I just bought a brand new distributor with cap and rotor. Next is the fuel pressure test!

Thanks guys!
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Old Apr 3, 2005 | 12:39 PM
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From: Salem, NH
Car: 1999 Z28
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23 10 Bolt
Originally posted by GM Man
All brand new stuff. Using Accel 8.8 wires and I just bought a brand new distributor with cap and rotor. Next is the fuel pressure test!

Thanks guys!
is the coil new?
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Old Apr 3, 2005 | 01:16 PM
  #12  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
Originally posted by SLP IROC-Z
is the coil new?
Nope, but I just swapped it with another that is known to be good. Hopefully the pressure test will tell me what I need to know. Thanks!
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Old Apr 3, 2005 | 05:33 PM
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From: Salem, NH
Car: 1999 Z28
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23 10 Bolt
let us know
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Old Apr 3, 2005 | 06:03 PM
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From: E.B.F. TN
Car: Tree Huggers
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Test the fuel pressure first. I'd test the ignition module as well as going over the dizzy and components again.
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Old Apr 3, 2005 | 06:34 PM
  #15  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
Oh I'll let everyone know what the pressure is when I get a chance to test it. Thanks everyone for your input!
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Old Apr 4, 2005 | 09:11 PM
  #16  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
Well I put a fuel pressure guage on the Camaro and it was all over the place from 38-42lbs. The guage would flicker the whole time, never staying in one place at a time. So what do you guys think?

Thanks.
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Old Apr 4, 2005 | 09:14 PM
  #17  
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
was this at idle or under load? i think at idle the thing is suppose to be at 42.
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Old Apr 4, 2005 | 09:16 PM
  #18  
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
oh...make sure your fuel filter isnt installed backwards...my auto tech teacher had a complaint when he worked for BMW that was like this...and when he drove the car with the fuel pressure gauge taped to the windshield...and at WOT itd cut out up top because the fuel pressure would fall...the filter was installed backwards from the factory...just be sure.

i think this is definitely fuel relate dbut thats me
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Old Apr 4, 2005 | 09:28 PM
  #19  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
I double checked that the fuel filter isnt backwards, and it is a new Fram filter. The guage was all over the place no matter what the RPM was. The only time it would kind of stay fixed in one place was when I would put it in neutral coasting to a stop. Thanks Dan.
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Old Apr 4, 2005 | 09:39 PM
  #20  
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
no problem.

by the way i checked my bill for the fuel pump replacement. i got some tru flow pump or somethin...106 bucks...then all the other little stuff like wiring harness and crap for it and it came to like 150 bucks for everything.

i remember my car did that...then i let it sit in the heat for a while when the exhaust was being put in...then they tested it and said the problem was still there (i was thinking i had a clogged cat)...yea so they told me to go take it for a test run...i tried, but the thing wouldnt move anymore if i stepped on the gas, it would just creep. the tow truck however jossled (is that a word) some fuel in the tank and i guess juiced up the pump for a little while so the next shot that had it kept saying the car was fine until they floored it. do you hear the pump priming if you just turn the electric on the car on?
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Old Apr 4, 2005 | 09:54 PM
  #21  
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From: Denver CO
Car: 1986 2.8 Camaro
Engine: TPI 350
Transmission: Tremec TKO
Yeah I can hear the fuel pump prime up when I turn the key to the on position.
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Old Apr 4, 2005 | 09:57 PM
  #22  
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From: Vineland, NJ
Car: 1987 IROC-Z
Engine: 350 TPI
Transmission: 700R4
that was a dumb questioni asked...its not completely dead then if you hear it, but then again if the car is running it wouldnt be dead anyway...fuel pump relay maybe? i dont know we are going into uncharted land for me...im not too too knowledgable...

it was determined my fuel pump was bad when the car was hooked to an injector cleaner...which had an on board fuel pump...everything smoothed out when running off that.

Last edited by IROCZ28dan; Apr 4, 2005 at 10:00 PM.
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