More on "The Problem"
 

Ok, the Fuel Filter and Spark Plugs are on the way (should arrive tomorrow or Tuesday). Yesterday I cleaned out the throttle body and cleaned/oiled the K&N filter. It helped a little, but the accelleration problem is still there. The car pulls like hell at about 3200-4500RPM as long as the upshift/downshift drops the revs right in that area. If I accellerate from low RPMs, the car accellerates slowly, and also accellerates (and Revs) slowly after about 4500RPM. If I mash the throttle at 5000RPM, there is NO difference in accelleration or rev climbing than if i was only gradually pushing the throttle.

Do we still think it's the fuel system?

Is the stock chip in there for sure? I didn't read the first post, maybe it's electrical.

yeah stock DME

CJ I dont remember the original post to well did anyone suggest the TPS?

well, your car should definitely be pulling hard at 5000, that much I know. If you hit the gas at 5000, the response should be the car 'takes'. then as the turbo spools, the thrust should push and push quickly to redline. Hope you work out the problem, and for little $.

um 944NA, not Turbo. 1983 model.

Yes the TPS was suggested. It seems that the only way to test the TPS is with an ohmeter (sp?), which I don't have. If someone could recommend a way to 1) get to the TPS, or at least the part of the TPS I need to adjust, without removing the throttle body, and 2) tell me how to adjust it, then I would be most appreciative.

FYI, here's a list of my approaches to remedying the problem:

THROTTLE CABLE: Cable was a little loose on new throttle cam. I adjusted the cable with the screw that connects the cable to the firewall, as well as the small screw underneath the cam. This made the throttle ultimately more responsive, and therefore improving accelleration, but didn't correct my problem

THROTTLE BODY: Removed main hose (the big black thingie that connects the body with the MAF), and cleaned the inside of the throttle body with the butterfly valve closed. I made sure that all the vacuum lines were clean by inserting a needle into each one. Throttle body wasn't dirty/clogged to begin with, so difference was not noticable.

AIR FILTER: Cleaned and oiled filter. Difference was negligable.

FUEL FILTER: Being delivered sometime this week, after which I will replace.

SPARK PLUGS: Being delivered sometime this week, after which I will replace.

THROTTLE POSITION SWITCH: Nothing attempted yet; not sure what to do... will attempt tomorrow morning if someone can help me figure it out.

FUEL PUMP: Nothing attempted yet.

FUEL INJECTORS/FUEL RAIL: Nothing attempted yet, other than running injector cleaner.

CLUTCH: Nothing attempted yet.

DME: Nothing attempted yet.

Thanks, all, any info/opinions/ideas you can give would be much appreciated.

IIRC my vote was for fuel filter replacment. Try it and see what happens. If nothing else its good PM.

Sorry but I have no insight on the TPS procedure.

but of course Clark has:

http://www.clarks-garage.com/shop-manual/fuel-06.htm

Oops- I don't know what made me think turbo. Its not me, its the LSD I ordered;)

Disconnect the O2 sensor and see what happens also.

Does your car still have it's catalytic converter? Does the console area and floor feel really warm when you drive it? If so, maybe your converter is plugged.

Rob

"Does the console area and floor feel really warm when you drive it? "

YES! Especially during the day, there is constantly HOT air blowing out from under the dash.

Any recommendations? I have a spare exhaust set-up... should I swich over to that one and see if it makes a difference?

Also: how difficult would it be to install my spare exhaust system on my car? Is there a way to simply swap out the cat?

new plugs and wires probablly.... maybe even a cap and rotor, might as well... good luck..

Frank B

if you replace everything rear of the the manifold back it would just be a matter of trying to loosen super rusty bolts. the cat is unfortunately welded in

"new plugs and wires probablly.... maybe even a cap and rotor, might as well... good luck.. "

I doubt it. I just got a set of Jacobs wires about 1 year ago, and the plugs don't look too fouled (just normal wear). I am changing the plugs as soon as they come in (they were backordered).

OK here's a list of things I have checked, and the diagnosis:

AIR FILTER - Cleaned and re-oiled with K&N kit.

FUEL FILTER - replaced with new item. Saw an improvement in response and an elimination of hesitation, but no cure to "the problem."

FUEL INJECTORS - ran fuel injector treatment/cleaner. No discernable difference. Injectors/rail are not leaking, hissing, or bubbling.

FUEL PUMP - nothing done yet

DME -nothing done yet

SPARK PLUGS - going to be replaced with new items

SPARK PLUG WIRES - wires aren't that old (1 year max)

DISTRIBUTOR - nothing done yet

ROTOR - nothing done yet

CLUTCH - needs to be replaced, has needed to be replaced since I bought the damn car. Clutch is not slipping, only makes 'whining' noise on decelleration and doesn't quite 'grab' like it used to.

EXHAUST/CAT - nothing done yet

THROTTLE WIRE/CAM - tightened wire so that cam/TPS clicks as soon as the throttle is touched.

THROTTLE POSITION SWITCH - tested with an ohmeter. functioning properly.

THROTTLE BODY - cleaned out. spotless.
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perhaps I should get a new distributor and see where that goes? Or maybe I should just wait until i get my clutch replaced under the assumption that the clutch is the problem?

Well, that is not really what I meant, typically when a conveter gets clogged, the floor and console area will get very warm from the converter heating up. Drive the car for a little while and feel with your hand to determine if the tunnel under the console is getting warm in any section more so than another. If so, I would replace the cat with either another one or a muffler/glass pack if you don't car about emission/car inspections.

The constast hot air blowing is a completely different problem. Possibly a bad heater valve. Do the early models have the notorious heater clips like the late models?

Get a can of PB blaster (This stuff is really amazing for old rusted bolts) from your local Autozone or simular auto chain and spray all the bolts a couple times, then let it soak in for a few minutes before attempting to loosen them.

Rob

Good idea its easy and wont cost anything.

Have you had the CO level checked?

I am not sure about the 944 but in addition to the TPS I would check any sesnors on the fuel injection and airflow. Also I remember some posts about the air intake having a flap that could get stuck or not function properly.

The cat could be replaced with a test pipe. However emmisions testing would be a problem if its required in your area. Sometmes when a cat gets cloged it will glow red hot. Run the car hard for about 30 mins then look underneath if the cat is glowing then its definatley cloged.

I have never worked on a 944 so I am just guessing but it does sound like a fuel mixture issue not a bad cat. I also would not buy a new distributor unless you have the old is bad. Throwing parts at the car gets expensive and frustrating.

Yes...Rich/lean adjustment may be needed. These cars with high mileage need readjusted at the MAF to reset the correct mixture. Over time and miles the DME is still set at new mixture. There is a cap on the MAF, drill and tap the plug and remove it with a screw-thats what the tap is for. There is an air mixture adjustment screw under the plug. You will need to have the O2 measured at the exhaust, most shops will be able to do this and get a reading of rich/lean and adjust accordingly. This will get the air mix closer to what the worn motor needs now and will run a bit better! The DME can only read the mixture not adjust it if too lean or rich. Sman

924Sman - could you go through the MAF procedure again in detail? i am not as mechanically-versed as many on the board, and therefore need more help finding the right things and a lot of detail in checking/fixing them...