944 hesitation after startup

josh912 · 10-21-2001, 03:40 PM

I'm driving a 944 which gives hesitation a minute or so after startup and it only lasts for about a minute or 2. During this time of hesitation the car is absolutely guttless. If you give it more throttle and it just surges, not going anywhere. The only thing you can do is give it minimal throttle for a minute or so, then it clears up and runs absolutely fine for the rest of the time you drive the car. It only happens when the car is cold or has been sitting for a while. The engine is in perfect mechanical condition and has 314k miles. This problem has been occuring for the last 100k. Any ideas?

------------------
Joshua Harrison
Porsche owner at heart

Cebu · 10-21-2001, 04:33 PM

I would Suspect the fuel Pump.Fuel pump check valve. I suspect fuel is draining back to the fuel tank and it takes a bit to get sufficient pressure back to the fuel rail. Check fuel rail pressure after overnight shutdown. I have this intermittrently and turn the ignition to "on" so that the fuel pump is running,count to 20 and start the engine it runs smoothly. Fuel system/Injector cleaner has lessened the problem considerably.

Blackfoot · Blackfoot's Garage

314k? are you that desperate, or is it selling for something like $1500? you might want to look at one with...normal miles.

AFJuvat · 10-21-2001, 05:10 PM

How does it start/run with the engine hot?

AFJuvat

T86951 · 10-21-2001, 06:01 PM

I have 205,000 miles on my NA 944 that I drive every day. Could be your throttle switch or a bad plug. Thats a hard one to figure out I have a rough idle cols start problem for a year now and when it warms up its fine. I have no answer for you problem but just wanted to let you know others have problems that are hard to figure out too. Miles on a well kept 944 mean nothing. I know of one with 400,000 and it runs great.

Britwrench · 10-21-2001, 07:54 PM

It could be a defective coolant sensor.

Probable cause is poor injector spray pattern ir excessive carbon on the intake port causing lean-run condition. Needs proper diagnosis before replacing any parts!

josh912 · 10-21-2001, 08:07 PM

I'm not buying it, I'm driving it. I also know this car very well. The car has been a 1 owner (also owner of a 928 and Boxster S) and has been well serviced, with all the records. The car was imaculate, until he let his son use it for college. 4 years later, its trashed, paint and interior. Otherwise great car. As for me, I'm saving up for a 86 or newer 944 N/A.

As for the car, it only does it when cold. It also idles lower and serges at idle at about 600 rpm. When it clears up it idles about 900 rpm, with no vibrations, and runs great from then on. Also if you gun it during its hesitation stage it will miss, sometimes.

------------------
Joshua Harrison
Porsche owner at heart

944jeff · 10-23-2001, 10:42 AM

I would not rule out the DME relay. My car was doing EXACTLY what you described and then eventually got worse to where it would quit running going down the road.

josh912 · 10-23-2001, 03:34 PM

Ok, I tried letting the fuel pump run for 20 seconds, didn't help. I did however pay close attention to how it ran, and what the exhaust sounds like. I think its running on 3. I'm not use to all this electronic stuff, so thats what I thought. I've been running chevron so the injectors should be clean? As far as the coolent sensor or the dreaded DME relay, how can I go about checking them. Thanks

------------------
Joshua Harrison
Porsche owner at heart