Engine shudder, loss of power
07-07-2009, 01:55 PM
#1
4th Gear
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Engine shudder, loss of power
Hello,
I have been browsing the "rough idle" posts to see if I can diagnose the problem I am having with my '87 924. I recently had the head serviced, (replaced 2 valves, 4 guides and all seals). Replaced the Idle Control Valve, replaced all injectors, oxygen sensor has roughly 2k miles on it, new cap & rotor, new wires, new plugs, replaced all vacuum hoses. Once I put the car back together it ran beautiful for about 50 miles. I took the car out the next day and noticed that there was a lot of hesitation in 2nd gear between 1000-2000 rpm. As soon as the rpm's reach 3000 the car smoothes out and drives awesome. So, first I swapped the wires with old wires, no change. Adjusted the MAF as described on Clark's(awesome 924/944 website!) website with not really much change. I finally took the car into the local shop and they tested the compression(good), vacuum leaks(none found) and told me that the #1 cylinder is misfiring and that it was most likely the injector. So I took the car home and put my old injector back into the car with very little change in the performance. The odd thing is that if I baby the throttle in first then when I go into second gear the studdering is not that bad but if I stomp on the throttle in first gear the studdering seems to go on past 2000 rmp and well into 3500 rpm and alos thru the rest of the gears. I have no clue on what to do next, replace TPS or the MAF. I do not want to just throw money into the car as my wife is already at the end of her ropes with this car. Any info or suggestions will be greately appreciated.
I have been browsing the "rough idle" posts to see if I can diagnose the problem I am having with my '87 924. I recently had the head serviced, (replaced 2 valves, 4 guides and all seals). Replaced the Idle Control Valve, replaced all injectors, oxygen sensor has roughly 2k miles on it, new cap & rotor, new wires, new plugs, replaced all vacuum hoses. Once I put the car back together it ran beautiful for about 50 miles. I took the car out the next day and noticed that there was a lot of hesitation in 2nd gear between 1000-2000 rpm. As soon as the rpm's reach 3000 the car smoothes out and drives awesome. So, first I swapped the wires with old wires, no change. Adjusted the MAF as described on Clark's(awesome 924/944 website!) website with not really much change. I finally took the car into the local shop and they tested the compression(good), vacuum leaks(none found) and told me that the #1 cylinder is misfiring and that it was most likely the injector. So I took the car home and put my old injector back into the car with very little change in the performance. The odd thing is that if I baby the throttle in first then when I go into second gear the studdering is not that bad but if I stomp on the throttle in first gear the studdering seems to go on past 2000 rmp and well into 3500 rpm and alos thru the rest of the gears. I have no clue on what to do next, replace TPS or the MAF. I do not want to just throw money into the car as my wife is already at the end of her ropes with this car. Any info or suggestions will be greately appreciated.
07-07-2009, 02:02 PM
#3
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Thanks for the quick response! I unplugged it while the car was running last night and it sounded like it was goin to stall so I plugged it back in. Would you happen to know of any reputable place that rebuilds MAF units.
07-07-2009, 02:39 PM
#4
Rainman
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not to sound picky but it is not a MAF, it is an AFM...AirFlow Meter, not MassAirFlow...they work differently and you would be hard pressed to find a 944 MAF repair shop.
You can buy them new but you'd be better off just getting a known good used one for $50.
Also check your TPS, if the TPS and the other stuff is all working properly the engine should idle fine without the AFM plugged in. Throttle position might be off or the TPS is bad.
You can buy them new but you'd be better off just getting a known good used one for $50.
Also check your TPS, if the TPS and the other stuff is all working properly the engine should idle fine without the AFM plugged in. Throttle position might be off or the TPS is bad.
07-07-2009, 02:58 PM
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Not picky at all, thanks for the correction. Man, I should have signed up to this site the first day I had my car. Thanks again for the advice. I will start with the AFM and throttle position sensor. Will keep you posted. Thanks again!!
