no trottle response Qs?
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no trottle response Qs?
First of all, my truck is a B4000 4.0L 4x4 94 manual hubs...automatic tranny
when I press the gaz pedal (full trottle), the engine seems to die about 1-2sec and after that it rev to 5k but verry badly...I don't know what it is...
When I disconnect the MAF, Engine light is on, and the truck runs fine(well, rich but fine), is it because the computer ignore all the sensors when the MAF is disconected?
I cleaned the MAF and it helps a bit, but is there any ways I can test the fuctionnality of it before changing it? btw, Engine light is on when pluged but the code is for the canister sensor...
What can I check?
Thanks a lot guys!
when I press the gaz pedal (full trottle), the engine seems to die about 1-2sec and after that it rev to 5k but verry badly...I don't know what it is...
When I disconnect the MAF, Engine light is on, and the truck runs fine(well, rich but fine), is it because the computer ignore all the sensors when the MAF is disconected?
I cleaned the MAF and it helps a bit, but is there any ways I can test the fuctionnality of it before changing it? btw, Engine light is on when pluged but the code is for the canister sensor...
What can I check?
Thanks a lot guys!
Last edited by CoolSpot; Jun 30, 2004 at 06:05 PM. Reason: adding question icon
Post Fiend
Joined: Feb 2003
Posts: 6,940
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From: Eastern WA
Welcome to FTE!
I would begin by fixing the known problem then check for codes again. FYI, on a 94, you don't need special equipment to pull codes. At this point, I'm not convinced you have a MAF problem. How is driveability?
I would begin by fixing the known problem then check for codes again. FYI, on a 94, you don't need special equipment to pull codes. At this point, I'm not convinced you have a MAF problem. How is driveability?
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Thanks
well, when you try to accelerate (full trottle, cause if I go smothly it doesn't do that), the truck dies1-2 sec....look like not enought gaz...or to much...and after that it's better. But when I'm at full trottle in 1st gear at like 5000, the engine hesitate before the tranny switch in 2nd...
I've changed the plugs and wires and don't know what to do next...
well, when you try to accelerate (full trottle, cause if I go smothly it doesn't do that), the truck dies1-2 sec....look like not enought gaz...or to much...and after that it's better. But when I'm at full trottle in 1st gear at like 5000, the engine hesitate before the tranny switch in 2nd...
I've changed the plugs and wires and don't know what to do next...
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
I had a remotely similar problem last fall; idle was great but unable to accelerate to speed and almost undriveable. This only happened when hot. In the end it was, oddly enough, the IAC, yet pulling codes didn't directly show the IAC solenoid was bad. The codes (157 and 158 I think) indicated a MAF problem, but the IAC needed to be addressed first per the repair flow diagrams I was using. After the IAC issue was resolved there was no MAF problem.
As I recall, with the engine running you can pull the wire on the IAC and the idle should drop to maybe around 600. You can also run the pinpoint test on the IAC solenoid.
For the next step, I would still fix the known issue first, clear codes and take a drive. I assume you have looked around for loose/damaged vac lines and electrial issues. If the problem repeats itself, pull the codes again and post them here. If I HAD to guess, I'm suspecting TPS or IAC, but don't throw parts at things and hope for the better; it's potentially expensive. Do the diagnostics first. Do you recall what the # of the code was that you have now? BTW, do you know if that code you have now was there before this problem surfaced?
As I recall, with the engine running you can pull the wire on the IAC and the idle should drop to maybe around 600. You can also run the pinpoint test on the IAC solenoid.
For the next step, I would still fix the known issue first, clear codes and take a drive. I assume you have looked around for loose/damaged vac lines and electrial issues. If the problem repeats itself, pull the codes again and post them here. If I HAD to guess, I'm suspecting TPS or IAC, but don't throw parts at things and hope for the better; it's potentially expensive. Do the diagnostics first. Do you recall what the # of the code was that you have now? BTW, do you know if that code you have now was there before this problem surfaced?
Last edited by CowboyBilly9Mile; Jul 1, 2004 at 01:02 PM.
