91 running very bad
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
91 running very bad
Hope somebody on here has some ideas?
91´ Coupe, Aut. All of a sudden the care runs very bad, and cannot idle anymore. When you try to keep it alive, it runs very rough, or not at all.
Changed the fuel filter, and fuel pressure is OK.
I have never worked on a MAP car before, could the MAP sensor be at fault, causing this?
91´ Coupe, Aut. All of a sudden the care runs very bad, and cannot idle anymore. When you try to keep it alive, it runs very rough, or not at all.
Changed the fuel filter, and fuel pressure is OK.
I have never worked on a MAP car before, could the MAP sensor be at fault, causing this?
Last edited by Lars87; Nov 1, 2011 at 03:17 PM.
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
Hope somebody on here has some ideas?
91´ Coupe, Aut. All of a sudden the care runs very bad, and cannot idle anymore. When you try to keep it alive, it runs very rough, or not at all.
Changed the fuel filter, and fuel pressure is OK.
I have never worked on a MAP car before, could the MAP sensor be at fault, causing this?
91´ Coupe, Aut. All of a sudden the care runs very bad, and cannot idle anymore. When you try to keep it alive, it runs very rough, or not at all.
Changed the fuel filter, and fuel pressure is OK.
I have never worked on a MAP car before, could the MAP sensor be at fault, causing this?
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
Check engine light?
If no, IAC (Idle Air Control valve) mounted to bottom of throttle body is possibility or you could have a clogged catalytic converter or base timing is wrong. Check for check engine light first and see if that points to anything.
If no, IAC (Idle Air Control valve) mounted to bottom of throttle body is possibility or you could have a clogged catalytic converter or base timing is wrong. Check for check engine light first and see if that points to anything.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Racer
Joined: Sep 2011
Posts: 352
Likes: 6
From: Centreville Maryland
Rather than "try this, try that" expensive trouble shooting technique, why don't you take it to a well equipped, competent shop and have them put an advanced computer scope analysis on the engine. They should be able to isolate the problem quickly (saves money) and then replace only the parts needed. (saves money)
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Former Vendor
Joined: Aug 2011
Posts: 101
Likes: 0
From: Cincinnati OH
My off-topic GM vehicle did the same thing recently. The "all of the sudden" was the car going into closed loop, and wound up being a dead coolant temp sensor. Just some food for thought!
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
Here is the status:
Car can not run, at all. Pressing the throttle while trying to make it idle does not change a thing. Turnds over fine, then dies.
No codes. I did the papir clip thing, and no codes. No SES light.
Fule pressure is perfect. Filter is changed.
All injectores are a 16ohms
While I turned the engine over, my buddy held a can of "engine start spray" into the intake. Then the car ran just fine, on the start spray.
So Ignition is there. But no fuel I guess.
I am pretty frustrated that the car does not set a code
Car can not run, at all. Pressing the throttle while trying to make it idle does not change a thing. Turnds over fine, then dies.
No codes. I did the papir clip thing, and no codes. No SES light.
Fule pressure is perfect. Filter is changed.
All injectores are a 16ohms
While I turned the engine over, my buddy held a can of "engine start spray" into the intake. Then the car ran just fine, on the start spray.
So Ignition is there. But no fuel I guess.
I am pretty frustrated that the car does not set a code
Instructor
Joined: Jun 2010
Posts: 131
Likes: 0
From: Shreveport Louisiana
I'm gonna say it again, clean out the tank and put on a new in tank fuel pump pick up filter.
I had the exact same problem and when I did this it solved it all. The pick up was ripped and gunk was getting in and clogging the lines and eventually the in line filter.
I had the exact same problem and when I did this it solved it all. The pick up was ripped and gunk was getting in and clogging the lines and eventually the in line filter.
Team Owner
Joined: Jul 2004
Posts: 28,431
Likes: 3,285
From: Hartford WI
Here is the status:
Car can not run, at all. Pressing the throttle while trying to make it idle does not change a thing. Turnds over fine, then dies.
No codes. I did the papir clip thing, and no codes. No SES light.
Fule pressure is perfect. Filter is changed.
All injectores are a 16ohms
While I turned the engine over, my buddy held a can of "engine start spray" into the intake. Then the car ran just fine, on the start spray.
So Ignition is there. But no fuel I guess.
I am pretty frustrated that the car does not set a code
Car can not run, at all. Pressing the throttle while trying to make it idle does not change a thing. Turnds over fine, then dies.
No codes. I did the papir clip thing, and no codes. No SES light.
Fule pressure is perfect. Filter is changed.
All injectores are a 16ohms
While I turned the engine over, my buddy held a can of "engine start spray" into the intake. Then the car ran just fine, on the start spray.
So Ignition is there. But no fuel I guess.
I am pretty frustrated that the car does not set a code
Team Owner
Joined: Jul 2004
Posts: 28,431
Likes: 3,285
From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,431
Likes: 3,285
From: Hartford WI
Thread Starter
Melting Slicks
Joined: Jul 2004
Posts: 2,295
Likes: 14
From: Grand Sport #82
UPDATE. Now this is getting really weird.
The in tank filter is fine. Since the Fuel pressure is good, and the pressure does not drop when cranking it, that was is suspected.
Car does still not run at at, it cranks fine, but it dosent even sputter or try to fire, just cranks.
O2 disconnected, no change.
MAP disconnected, no change.
TPS voltage fine.
Injector fuse for bank 1 and 2 OK
Tried to hook up spare injector to one of the connectors, and cranked the engine whine by buddy held the injector. We do not feel any ticking or similar, as I would expect.
we measured the volt on the injector wire. They are constant battery voltage, and does not change as you crank the engine.
To me this means that differently the car does not get any fuel, sine the injectors are not opening. As mention Fuel pressure is fine, and does not drop.
Also the car runs fine when spraying start spray directly into the intake. So ignition is fine too.
So, could this be the ECU?? Or is there more we could check here?
The in tank filter is fine. Since the Fuel pressure is good, and the pressure does not drop when cranking it, that was is suspected.
Car does still not run at at, it cranks fine, but it dosent even sputter or try to fire, just cranks.
O2 disconnected, no change.
MAP disconnected, no change.
TPS voltage fine.
Injector fuse for bank 1 and 2 OK
Tried to hook up spare injector to one of the connectors, and cranked the engine whine by buddy held the injector. We do not feel any ticking or similar, as I would expect.
we measured the volt on the injector wire. They are constant battery voltage, and does not change as you crank the engine.
To me this means that differently the car does not get any fuel, sine the injectors are not opening. As mention Fuel pressure is fine, and does not drop.
Also the car runs fine when spraying start spray directly into the intake. So ignition is fine too.
So, could this be the ECU?? Or is there more we could check here?
Team Owner
Joined: Jul 2004
Posts: 28,431
Likes: 3,285
From: Hartford WI