Fuel Pressure problem perhaps?
Thread Starter
Member
Joined: Jan 2003
Posts: 46
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From: Texas
Fuel Pressure problem perhaps?
OK Here is the setup
'88 T3g Ls 5-speed
- ECU says MAP error (manifold absolute pressure)
- I replaced wires and plugs
- Drive in 1st works fine
- 2nd gear and up i get good bottom, but when i get to 4-4200 rpm I get serious hesitation then loss of power until i let go of gas. Then if i find a right spot on the gas it will slowly acelerate.
- if i press the clutch in while in motion and rev.. it revs fine, until clutch is engaged again then there is gas hesitation. It drove fine about 2 weeks ago and since i pulled ecu and interioir it does not drive properly.
- Trannny and clutch are not issue.
*** I am thinkinf loss of fuel pressure, but i also noticed a crack on the air intake where the Oxygen sensor is. Coudl the loss of pressure on the o-2 sensor do this or would it most likely be fuel pressure?????
I tried the spraying carberator cleaner on the hoses, but i am unsure where i mshould do this. The fluid should make the engine rev if it is sprayed over a crack in a hose. It revs fine in nuetral and not until moving does the as hesitate.
If there are any ideas please let me know, or if there are any questions you need answere to help me diagnose this please et me know.
AIM= Paymepunk
'88 T3g Ls 5-speed
- ECU says MAP error (manifold absolute pressure)
- I replaced wires and plugs
- Drive in 1st works fine
- 2nd gear and up i get good bottom, but when i get to 4-4200 rpm I get serious hesitation then loss of power until i let go of gas. Then if i find a right spot on the gas it will slowly acelerate.
- if i press the clutch in while in motion and rev.. it revs fine, until clutch is engaged again then there is gas hesitation. It drove fine about 2 weeks ago and since i pulled ecu and interioir it does not drive properly.
- Trannny and clutch are not issue.
*** I am thinkinf loss of fuel pressure, but i also noticed a crack on the air intake where the Oxygen sensor is. Coudl the loss of pressure on the o-2 sensor do this or would it most likely be fuel pressure?????
I tried the spraying carberator cleaner on the hoses, but i am unsure where i mshould do this. The fluid should make the engine rev if it is sprayed over a crack in a hose. It revs fine in nuetral and not until moving does the as hesitate.
If there are any ideas please let me know, or if there are any questions you need answere to help me diagnose this please et me know.
AIM= Paymepunk
Member
Joined: Jul 2002
Posts: 76
Likes: 0
From: san jose california
well the o2 sensor is in the exhaust for one but not your problem it does sound like you are not producing enough fuel pressure or maybe have a restriction. has the filter been changed? if not change it now then try again if still have same problem get a guage and check the pressure sometimes you gotta run the guage to the outside and drive the car while watching the pressure and see if it drops under a load. good luck
Wannabe yuppie
Joined: Dec 2000
Posts: 25,918
Likes: 0
From: Madison, WI
If you have a code for the MAP sensor, it probably means you have a bad MAP sensor. 
(Your MAP sensor is what tells the ECU how much air is going into the motor by way of comparing the pressure inside the manifold to the ambient pressure.)
(Your MAP sensor is what tells the ECU how much air is going into the motor by way of comparing the pressure inside the manifold to the ambient pressure.)