89magic98

I thought that on fuel-injected cars you did not need to depress the accelerator before/when starting the car.

Recently, it seems that depressing the accelerator while cranking is needed to start the my 924s. Not all the time, only occasionally. Total cranking time is pretty short - maybe 1-2 seconds.

Any thoughts on this? Do you need to step on the gas to start your car?

Thanks!

Yabo

from my experience, it should not effect it. Fuel injected cars, when you turn the key (cranking) the injectors squirt full blast until the dme kicks in and regulates it (once the car is started). That is why when you start the car, the firs second of running is high, then it settles down. The only thing holding the gas down should do, is perhaps help it catch after that second, keeping more gas entering the cylinders.

Henry964

From my experience when the engine is cold (more than 2 hours off) you should start it without pressing the pedal, when it is hot is better to accelerate about midway on

seb928s

Hmm check valve at the pump or FPR. When does this problem occur? Is it right after running the car when it's hot or over night then try to start it again? Does it happen no matter what the conditions are? Please give more information.

89magic98

It seems this problem is worse when the car has been shut off for 5 minutes. It seems to get better again when the car is cold again (20 minutes after shutdown with the hood open). I don't always have a hot start problem.

The check valve (and fuel pump) are less than 1 year old. The FPR is original. I have a new damper and FPR on the way (thought it was time to change them).

EDIT: Fuel filter changed less than 1 year ago. New DME relay. Fuse for the fuel pump has also been changed less than 1 year ago.

83na944

Shouldn't have to depress the accelerator pedal to start the car. If you had a car with a carbeurator, depressing the pedal would set the choke and make the accelerator pump squirt a little extra fuel.

I agree with seb928 that the FPR or check valve is defective causing low pressure in the fuel rail. But why its more of a problem when its warm is difficult to understand.

Sounds like a fuel pressure test is called for.

89magic98

On an N/A, when you depress the gas pedal at all, there's a contact switch on the throttle body that goes from ground (0 ohms resistance to ground) to open (infinite resistance to ground), right? This signal goes to terminal 2 on the DME.

Would the DME seeing this transition have anything to do with it? Just brainstorming here.

I need to find a M12x1.5 hose fitting to adapt my fuel pressure gauge to work with our fuel rail. Does anyone have a suggestion of where to source this?

Thanks for the feedback everyone!

Baron009

My manual says DO NOT (bold lettering and all) depress the accelerator when starting the car. It goes on to say that the computer automatically adjusts the amount of fuel as required or something.

That's about all I know haha. Sorry

bearone

same story on mine.

inactiveuser92616

today, after driving my car pretty hard for over an hour (pushing my way through Denver) I stopped for about 20 minutes. When I went to restart, I had to nurse the gas to keep it running, without supervision it was running down to 500RPM and misfiring. I think there is something in the DME or the equipment it governs that is affected by heat. Perhaps the high reading on the temp sender?

89magic98

Now, this happened to me last year, and it was driving me nuts.

In my case, there was a glass "bullet-style" fuse for the fuel pump, it separated just enough inside the glass to be intermittent. The funny thing was that the car would run if it started. Then it got harder to start. Then it started doing what you describe above. Finally, it would not start or run once started (unless I was connected the fuel pump power directly to +12v at the 9-pin connector in the engine compartment - on the other side of the fuse). I had been doing the same jumper trick to start the car.

DISCLAIMER - connecting the fuel pump to +12v inside the engine compartment is even more dangerous than replacing the DME relay with a jumper wire. In the event of an accident, the fuel pump will keep running (could start/fuel a fire), and you may not be able to disconnect the jumper wire in the engine compartment.

Early on, I had checked the fuse and ruled it out. It was the only glass-type fuse in my entire panel - the traditional red/white/blue ones are much easier to visually inspect. Please change the fuse (don't check it, change it) and let me know if your problem goes away.

jonnybgood

Mine starts without depressing the accelerator at all, hot or cold.