odd problem
 

Occasionally (about once every couple weeks or so) when I shut my car off it stops momentarily then turns over a few more times then dies. When I go to turn it back on it is difficult to start but always does after a few seconds.

It usually doesnt bother me but it seems to be getting a little more frequent.

Does anyone have any ideas? Thanks.

ok, shawn wanted me to post this:
"using cheap grade gas, like 87, can cause your car to diesel when shutting off, causing it to sputter a bit. the taking a lont time to start back up has to do with the check valve in your fuel pump. different problems, same cause, FUEL.

i agree with shawn..it's prolly just cheap low grade gas... add a can of octane booster if u can't get better gas.

I was thinking leaky injectors...

carbon buildup in the cylinder head can serve as an ignition source that can cause dieseling. try running a bottle of techron through.

<img src="http://home.pacbell.net/nirky/turbo_120usa.jpg">

Inproper mixture setting. Unburnt fuel in the head like Blackfoot stated.

hmmmm... yes I do use 87. I'll probably use a bottle of Techron, and if it still does it I will upgrade my gas. 110 octane, oh yeah! no, not really just 89/92.

i have that same problem but i use supreme gas, it only does it once in awhile, when i change my wires from oem ignition system to my aftermarket ignition system it helps for a little bit then it does it again then i have to change igition system back to oem. it also jerks a bit while driving. any help???

So does everyone here swear by Techron? My mechanic who is very familiar with 944s told me to try using it to clear up some of the cold running problems I have had, because he thinks its related to drity injectors. Also, has anyone had good luck with physically cleaning the injectors?

Kenne944..........

I would look at the rest of your ignition system as well. I am venturing that there is something else loose in that area. When you are swapping wires something is being affected. Check your distributor/rotor as well. I also had a hell of a time with an injector harness that was shorting that was giving me similar issues as well. Just don't start throwing parts at it..........systematically check each one.

NKN.......... Techron... It wont hurt. To be honest I have never used it. I have always tried to use good gas and never let the tank go below 1/4. I am sure dirty injectors would benefit but to what extent probably depends on the contaminant. They do have a screen in them that is meant to catch particles wether the techron will be enough to remove any foreign bodies within the injector/fuel lines I am sure its hit and miss...

In regards to cleaning injectors yourself Socal (uhmmm haven't seen him in a while??) swears by it. IMO I dont think its a do it yourself project but if you know what you are getting in to......... then go for it. I wont explain the procedure (search) but it involves flammable liquid and compressed air. :) RCengineering will also do the service for you if you dont want to tackle it.

Carbon build-up. You need to go drive the car hard to burn it out.

"Italian tune-up" time.

Your car is telling you it wants to spend a day at the track. Repeat as neccessary.

hmm i guess all that 93 Ive been running doesnt help LOL. Cept that the last 10-15 minutes to work I beat the hell out of my car..and it doesnt diesel like other times where I would just cruise to work.

Its kinda a love hate relationship. A Euro-rebuilt motor like mine with 10.6:1 compression doesnt seem to like anything else than 93, because it will knock, yet the car diesels if I just drive it normal. I have a small leak in one of the o-rings..I should get around to replacing all of them and cleaning the injectors.

My advice? beat the hell out of the car and wind it out and burn all that crap out. I forgot how many times between shifts my car would belch black smoke out the pipe. I wonder if the wilks chip will cure the over richness between shifts...or just make me blow smoke all the time under hard acceleration LOL.

I can get 114 octane where i live. Would the car like it, or would it be a waste of money?

Waste of money. Unless you are running really high boost, you don't need above 89/92. I run 87 octane in mine, never had any dieseling problems, however I do have a tendency to let it rev up sometimes. Sees 5k on a daily basis.

I swear by techron. I use it in all my vehicles, one bottle, twice a year. It cleared up a bad ping problem I had in the Mustang and increased by gas mileage significantly in the Tahoe and Porsche.

If anyone remembers my non-famous post on injector cleaning, I did do it when I resealed them. It involved a bicycle pump, carb cleaner, a 9V battery, and way too much time. Lemme find the post...

And I did notice a smoother idle after doing it.

Here you go- see my contraption here.

http://forums.pelicanparts.com/showthread.php?s=&threadid=146102&highlight=fool+m anaged