FirstPorsche

I have a 1987 944S and have been fighting a cold start problem for a while. I took the car 2x to Auto Associates in Canton, CT. $700 later they did not fix the problem.

I took my car to another guy to have my new clutch installed and he immediately tells me it is the "5th injector."

It is located behind and underneath the intake.

Does anybody have knowledge of this?

Thanks in advance for all responses!

Jfrahm

Hmmm. Maybe he means the IAC? That's under the intake but not at the back. It's a controlled air 'leak' past the throttle for idle operation.

-Joel.

944Ecology

There is no fifth injector on your car...

Perhaps the second shop thinks that you have CIS on your car (and that it's a 924)...

:-)

gb

FirstPorsche

Thanks for the replies. Well, I cannot figure out why the darn car has problems starting when it is cold.

At least it always starts eventually!

944Ecology

Well, it could be a bad temperature sender... If the signal to the DME is that the engine is hot, it will not richen the mixture and will result in hard cold starting.

gb

FirstPorsche

What and where is the temperature sender? Is it easy to replace? Do you sell these things?

Thanks.

Also, I just spent a week in King Ferry, NY (just north of Ithaca). My in-laws' property looks over the lake. Where are you in NY?

Joe

944Ecology

The temperature sender for the DME is located between the intake runners for cylinders 1 and 2, and has a locking connector (similar to that on an injector).

We do have these in stock, and sell them.

We are located in the Hudson Valley, near Kingston and Poughkeepsie, nowhere near Ithaca.

FirstPorsche

All right. I am at wit's end.

The car started and drove perfectly last Friday (three days ago). I did not drive it this weekend.

This AM it would not start. I had been using the "trick" where I press the gas pedal slightly and then it would start and idle fine. That did not work today.

After about 12 tries and then giving the car a "time out" it did start but would not idle. It would die. I could get it to stay running by pressing the gas pedal. But, if I let it idle by itself it would vibrate like mad and then die.

I have gotten some great advice from all of you about what to check but have not yet done it (shame on me).

Just venting at this point.

Joe
944S For Sale!

hacker-pschorr

928's with L-jet (barn door) injection also have a 9th cold start injector. With the rarity of 16V 944's, it's safe to say not many shops know much about them.

FirstPorsche

Well, just for fun, I installed a new "engine temperature sensor" last night. 3 hours later the car still would not start.

One of my mechanics is suggesting that we install 2 items: 1) cold start switch and 2) cold start valve.

Anyone want to buy a 944S??? Anyone?

Joe

jeeper31

What exactly is happening? Does it crank a long time before it starts? Does the idle seem to pulse once it is started? After it starts and you turn it off does it start right up?

porsche924

This might sound odd, but if it is pretty cold around you, it might have to do with your ignition. Dunno if there are ones that will fit the porsche plug wires very well, but i have this little light thing that goes in between the spark plug and the plug wire, if you get a blue light, you get a good spark, if you get a red light, it is crappy. I have heard on some other cars that the distrib rotor is kinda warn and when it is cold and a little bit of condensation that it will arc and give either crappy or no spark at the plug. try unplugging each wire(leave the plugs in the hole) and put a plug on the wire, ground it to the block being very careful where your hands are(dont wanna get shocked, so dont touch the frame with your body, even if it is clothed) and have someone crank the engine when it is cold and look at the spark. i know it is a good test for the 924 and other cars, not sure about the 944s so you might wanna wait untill someone says whether or not it is a stupid idea. Also i have heard that a shot coil will make a car very hard to start also. also when is the last time the battery was replaced? also does it smell like gas when it is running or does it smell kinda like burnt metal?

porsche924

oh yeah, go and get a can of the aresol carb cleaner spray, squirt it on every joint of the intake after the air sensor all the way to where the intake manifold bolts to the head, if it stumbles when you squirt it on a joint, then hello vacuum leak. handy little trick if you ask me.

just remembered this too, if you disconnect the battery (at least on the 944s2) and leave it disconnected for like 15-20 min, then reconnect it, it will reset the engine computer.

also my car starts quicker since i put a heavier ground wire in. go to the local car audio store and get a foot(a couple $) of amp wire (i used 4 gauge because i had some lying around) and two ring terminals. cut the wire to fit, put the terminals on and run it from the negative on the battery to where the current one is(i am lazy and didnt feel like looking) or find another good spot for it. i did this just because i added a system and figured i had the stuff anyway, my gas mileage went up and the engine seemed to run smoother and started quicker, especially when cold. the stock ground wire is way to small if you ask me and it is also 17-18 years old.

hacker-pschorr

If the mileage is accurate, I may be interested this spring.

FirstPorsche

UPDATE: This AM I decided to try the car again. Lo and behold it started right up! Really lumpy, bad idle. It was around 1,000 RPM. Sounded almost like a drum set. But it did idle by itself and did not stall. I revved the motor and this time, instead of stalling like yesaterday, the car would rev and it sounded perfectly fine as it was revved. When I let off the gas it would "hunt" a bit, almost die, and then it would go back into the rough idle around 1,000 RPM. I turned the car off, waited a few minutes and then started it again. It started up again but still had the rough idle. I revved it as before and it sounded fine again. I drove it around the block. It drove fine but, of course, when I came to s STOP sign it would go back to the rough idle. I put the carin the garage, revved it a bit more, and then it hunted at idle and then died.

What has been done to the car for this problem?
9/27/04 new Engine Temp Sensor
8/6/03 cap and rotor, plugs, fuel pressure checked OK, flywheel reference sensor replaced
7/23/03 intake checked for leaks w/smoke machine (none found), cold start temp sensor checked OK, checked for dirty injectors by adding injector cleaner.

My ideas (please comment):
Engine revs fine so not bad fuel and no need to replace fuel filter or fuel pump.
Bad DME? Maybe I should replace the little "tower" in the fuse box under the hood. I should also check the actual DME box under the passenger footwell (maybe it got wet?).
Replace spark plugs and spark plug wires.
I checked the battery voltage and it was good.
Air filter is clean.
I did my best to check electrical connections and vacuum hoses and found nothing amiss.

Thanks for listening.

Joe