Total power loss while accelerating?

D944 · 05-19-2008, 09:50 PM

Hi, any advice on my 87 944's latest issue would be greatly appreciated!

While accelerating, the engine will occasionally lose all power, for a split second before jolting forward and driving normally until this happens again. I have taken the car out and returned soon after due to the frequency of the "attacks," but have had entire afternoons without a glitch. I'm guessing it's electrical, but don't no where to start.

Thanks for any ideas.

rudidelange · 05-20-2008, 10:23 AM

If it happens at a specific throttle opening, irrespective of the gear, it would be my guess to look at the air flow meter. A full description how to test is available at:
http://www.clarks-garage.com/

D944 · 05-20-2008, 11:38 AM

I hadn't thought of the air pressure meter, will look i nto it. It seems as though the engine loses power at random throtle openings. Would this make any difference?

Thanks for the reply.

bud9344 · bud9344's Garage

Check your intake boot for leaks. any crack on the boot will prevent the door on the metering to open. Too much air not enough injector time to open

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Bud

bud9344 · bud9344's Garage

Remember the engine doesn't move or shake the same time to the the air filter box The engine sit on an engine mount and the air filter box sit on the frame.

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Bud

Aufenbahn · 05-20-2008, 12:14 PM

Also check your throttle position switch. If it's telling the ECU that the throttle is closed and you're above 1200 RPM I think it triggers the fuel cut off. I haven't proven this but I'm in the middle of trying to fix mine. When mine did it - it happened at wide open throttle only and it was repeatable, although I didn't particularly like doing it too often. It hasn't done it since but I have a replacement TPS that I'm going to install. Let us know what you find. Good Luck

D944 · 05-20-2008, 07:56 PM

thanks guys, I'm going to work at it tomorrow. I and will let you know the outcome. I'm wondering if the fuel pump relay could have a hand in this as welll, and how much attention it deserves... welll, will find out.

Physedfailure · 05-21-2008, 04:50 AM

keep us posted I have the same issue going on

rporzio · 05-21-2008, 07:17 AM

Me too...! I have an AFM waiting in the wings to replace mine. I had terrible pulsating idle issues until I resealed the units top cover. I did notice that condensation had built up inside and left a white residue all over the place.

I've cured the idle issue so I'm curious to see if its time to put in the new AFM to help with my "sometimes while accelerating cut-off."

JustinL · 05-21-2008, 12:31 PM

Pull the connector off the throttle position switch. It's the square plug underneath the throttle body. This will force the engine to use part throttle maps all the time. Fuel consumption will go up a bit if you drive like this, but this may tell you if the TPS is the problem.

cauzomb · 02:49 PM

Mine was the airflow meter, intermitten connection on the center wiper contact, as well as a worn carbon contact just off idle. I had the problem a while back on my first AFM, got water damaged and had carbon traces to ground on the ceramic surface from the water damage. Since I replaced that AFM I forgot to have a look at the current one for the update wire and carbon track wear, last couple of weeks it started bucking real bad and refused to idle.. I performed the repair's last night according to what was listed at frwilk's site, as well as clarks garage. Did the wire update too cause it's an older afm.. The repair and update fixed the off idle acceleration cutout and rough idle as well. Thank's to those guys for having the info available.