No power, engine bogs down

Tiny
NICKL
  • MEMBER
  • 1988 OLDSMOBILE CUTLASS
  • 2.8L
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 88,000 MILES
Engine developed problems about one hour into a 2 hr highway ride. Engine loss power and rolled to a stop while engine remained running, but as soon as throttle was pressed, engine began to bog down again and was unable to continue. Towed it home where I checked the following items. Fuel pressure is ok, within pressure range, 40lbs with engine off, 35lbs
at idle. With vac removed from fuel reg, pressure went to 43lbs, so assuming pump and regulator and filter are ok. When car is shut off, pressure holds for at least 30 min before starting to drop, so I think fuel reg and injectors are ok. I checked the map sensor, get 4.8v with key on engine off. If I create a vacuum it drops to 2.8, so that seems ok as well. Do not have test equipment to check mas air sensor, so I replaced it with no improvement. I also loosened the exhaust manifold to check for clogged cat, but that did not help. So I'm out of things to check. Any help would be greatly appreciated.
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Wednesday, August 31st, 2016 AT 7:24 AM

8 Replies

Tiny
HMAC300
  • EXPERT
Fuel pressure is to low should be 41-47 psi key on only regulator is ok but fix pump first. And replace fuel filter as well.
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Wednesday, August 31st, 2016 AT 7:49 AM
Tiny
NICKL
  • MEMBER
Is the range of 41-47. Where the pressure should be regardless of if car is at idle, or high throttle?
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Wednesday, August 31st, 2016 AT 12:44 PM
Tiny
NICKL
  • MEMBER
Checked pressure again, I get 40-41 key on engine off, when I give it throttle, I get 42-43 when it blogs down and when it runs normal. When I first start car it will run normal (in park, ) for the first 2 or 3 times I give it throttle then bogs down every time after that.. At idle its something less than 40. (35-38). Thats why I asked about what the range means in my earlier response. Thanks Nick
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Wednesday, August 31st, 2016 AT 2:49 PM
Tiny
HMAC300
  • EXPERT
It has to be a minimum of 41 psi with key on only or engine off. 40 psi is not enough. It will climb as you give it more gas it should reach max when off idle it's more than likely your fuel pump make sure to replace fuel filter as well.
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Wednesday, August 31st, 2016 AT 3:40 PM
Tiny
NICKL
  • MEMBER
Thanks, Be back after replacing it.
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Wednesday, August 31st, 2016 AT 4:28 PM
Tiny
HMAC300
  • EXPERT
With you saying it loses pressure that is a good indication of a bad pump it should not lose any pressure time after time.
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Wednesday, August 31st, 2016 AT 4:52 PM
Tiny
NICKL
  • MEMBER
I pinched off fuel pump return line and got 85lbs at manifold, so started looking other places. One of the injectors I could get at read.04 ohms, so I replaced all 6. That was the only one with very low resistance, but fixed the problem. Running fine. For now. :) Thanks again for your help.
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Friday, September 9th, 2016 AT 1:01 PM
Tiny
KEN
  • ADMIN
Glad we could get it fixed please use 2CarPros. Com anytime we are here to help

Best, Ken
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Wednesday, September 14th, 2016 AT 5:25 PM

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