sschultze09

Hi, all
My car has always started with one try up until the start of this season. I thought it may have been old gas but that's not the issue as I've burned through the old gas. Even the second try is sketchy but it always starts on the second try. Any Ideas on where to start looking? I have searched is problem with very little luck.

TIA

sschultze09

Forgot to mention the problem only happens when the engine is cold.

DobermanDad

How old are your coils?

Mine was a hard starter cold, replaced them, she fires right up.

sschultze09

They are only a few years old. I replaced them when I did my plugs, wires, caps and rotors.

HalV

Might want to check your fuel pressure when cold.

sschultze09

Halv,
That's a thought. Do you know how and where to check the fuel pressure and the regulator?

911Jetta

More info please... Mine started on the first try all the time until the starter motor went bad.

Does it start to turn over, and then go silent? Or do you constantly hear the starter motor, but it won't start?
Everything feels good as you twist the ignition key, starter motor sounds good..then silence, and some clanging noises with a thud... see video.

sschultze09

Hi, Jetta
No it doesn't make the thud at all. It try's to start but its like the idle is very low. Sputters and try's to start then dies. On the second try it sputters and finally takes off and the idle steady's off. I just cant tell if its fuel related or electrical or even idle speed.

C24FUN

I find that as the season changes from winter to summer (and vice-versa) my cold start behavior often goes to "two-try" mode! The cure for me has always been an "adaptation" using my Scantool. It seems that the change in temp/humidity from season to season requires compensation in the ISV opening to get a good idle mixture.

Just my 2 cents worth.

Jim G.

Poli84

I've just had this problem cured on my 964 however a lot of work was done so it might be difficult to pin point.

I've owned the car for 9 months and every single cold start (first in the morning), would stall after first attempt and then start with the second.
- easy to stall when taking off
- kangaroo hopping in traffic
- rev drop when coming to a stop, often resulting in a stall
- huge rev fluctuation at idle, etc, etc

I tried cleaning the ISV and the AFM, didn't work so I changed to a new ISV and O2 sensor, didn't work.

Mechanic started with an AFM calibration which helped but wasn't the fix.
Reconfigured the Idle Micro Switch after a past mechanic had molested it, again helped but not it.
Checked for all air leaks, etc, nothing found.
Plugged in another ECU and the idle improved so they sent the ECU and some changes were made to match the test ECU and the result is now an even better car to drive with a strong idle, starts first go every time, etc, etc.

Worth while to note that in the last 20k km's I have had
New starter motor, alternator, plugs, leeds, dizzie caps and rotors.

As I said, can't tell which cured the problem but my mechanic is confident that it was the ECU changes.

Andy Roe

My guess would be the fuel pressure.

The next time you try to start it from cold, turn the ignition on and then wait a few seconds before starting the actual engine. This should give the fuel pump some time to build up some pressure in the system. If the engine then starts ok then it could either be the fuel pump, or the fuel pressure regulator. The fuel pressure regulator normally gives hot start problems when it starts to fail though from what I've read.

DobermanDad

+1

Yeah, I think a bad fuel pump regulator causes hot start issues too.

A dirty fuel filter will cause poor starting.

elbeee964

Is the Idle micro switch 'Off' while the accelerator pedal sits untouched?

That was messing up my 964 till a Scantool showed me the Idle switch was 'Off' just sitting there idling. (Albeit idling REALLY badly.) Backed off the throttle cable tensioning nut (under the car) till the switch showed 'On' -- and the car's idled beautifully ever since.

And while you've got it hooked up, check the WOT switch clicks 'On', too... with the engine off, of course!

You can check/do both adjustments with the engine off.

speedbagger

i'm experiencing a similar a issue to the op and just ordered two new coils. will install this weekend and report back.

i've gone through almost identical troubleshooting but i've also replaced my fuel pressure regulator and filter with no change. could it be the pump? maybe, but i've got records from the po that show this was replaced a few year back. i normally key to ignition pretty quickly so i'll try the suggestion of letting the pump prime the system.

what coils are you guys using? i've read through the threads here and am familiar with the silver bosch concerns but confused over compatibility of the msd offerings (which is what i ordered).

DobermanDad

I used Silvers. I immediately noticed a difference on start up once I installed them. I mean she fired right up.

I've also be going thru all my cars electrical contacts, spark plug caps, and grounds, cleaning, and using dielectric grease on them. Seems to be improving everything. Just did the ground behind the alternator while it's out.