Can someone tell me why?
Thread Starter
Senior Member
Joined: Dec 2004
Posts: 556
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From: my garage
Car: 84 firebird T/A
Engine: shinny 350
Transmission: slush box L65
Axle/Gears: Torsen "3.73"
Can someone tell me why?
My car has never hit the road as of yet and I keep experiencing the same problem while just running it in the shop.
When the engine is started it will run for about two minuets or so then start running rough then stall. During this time the fuel pressure regulator starts fluctuating then goes to zero...this is the point at which the engine stalls. I can go right back to starting the car and it will fire right up with good fuel pressure then once again fall to zero and stall.
This is happened in the past. I pull the fuel pressure regulator cover off replace the diaphragm even though there is nothing visibly wrong with it and everything is fine as long as I run the engine every day. Once I let it sit for a couple of weeks this problem returns.
I checked both voltage and amperage while this scenario of the fluctuating regulator then falling off to zero takes place and they are steady and correct.
Has anyone else experienced something similar? If so what is the course of action needed to eliminate this condition.
thx
jeff
When the engine is started it will run for about two minuets or so then start running rough then stall. During this time the fuel pressure regulator starts fluctuating then goes to zero...this is the point at which the engine stalls. I can go right back to starting the car and it will fire right up with good fuel pressure then once again fall to zero and stall.
This is happened in the past. I pull the fuel pressure regulator cover off replace the diaphragm even though there is nothing visibly wrong with it and everything is fine as long as I run the engine every day. Once I let it sit for a couple of weeks this problem returns.
I checked both voltage and amperage while this scenario of the fluctuating regulator then falling off to zero takes place and they are steady and correct.
Has anyone else experienced something similar? If so what is the course of action needed to eliminate this condition.
thx
jeff
Senior Member
iTrader: (1)
Joined: Sep 2005
Posts: 629
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From: RVA
Car: 89RS,89TBI FB, 91Z28, 89TPI FORMULA
Engine: 357 SBC TPI
Transmission: World Class T-5 (for now)
Axle/Gears: Strange 12-bolt 3.73
Re: Can someone tell me why?
I had a similiar issue earlier this year. My symptoms were that the car would be fine for the first half an hour and then I'd have trouble launching the car. Under a constant load it'd be ok, but getting out of 1st gear was tough. The car would buck and die and get going again. I think I had 30 or less PSI of FP upon start up.
Turns out my fuel pump had a pulsator on it that had, after 18 years, failed. I read all the pros and cons on what to do and decided to replace the pump (I do NOT want to do this chore again) and replace the pulsator with a piece of fuel hose. That cured my ills and have not had any more pressure issues.
Turns out my fuel pump had a pulsator on it that had, after 18 years, failed. I read all the pros and cons on what to do and decided to replace the pump (I do NOT want to do this chore again) and replace the pulsator with a piece of fuel hose. That cured my ills and have not had any more pressure issues.
Thread Starter
Senior Member
Joined: Dec 2004
Posts: 556
Likes: 0
From: my garage
Car: 84 firebird T/A
Engine: shinny 350
Transmission: slush box L65
Axle/Gears: Torsen "3.73"
Re: Can someone tell me why?
Thanks
My fuel pump is an in tank style and is a brand new GM unit. I keep the gas cap loose because since I converted to TPI if I have the cap tight the pressure build up was considerable.
Do any of these comments lead to any other reason why the pressure would flux so irratically. I pulled the car out of the shop an hour ago and shut it off. When I started it back up it barelly ran well enough to get it back in the shop due to low fuel pressure. When I pulled it out it had full power.
thx
jeff
My fuel pump is an in tank style and is a brand new GM unit. I keep the gas cap loose because since I converted to TPI if I have the cap tight the pressure build up was considerable.
Do any of these comments lead to any other reason why the pressure would flux so irratically. I pulled the car out of the shop an hour ago and shut it off. When I started it back up it barelly ran well enough to get it back in the shop due to low fuel pressure. When I pulled it out it had full power.
thx
jeff