'82 928 Starting Problem

[Ramzel]

I am the owner of a 1982 928. On Friday, I thought that I had got bad gas. There was terrible hesistation when in park or at slow speeds. I did use the some type of gas treatment and it did improve the performance immediately. I then drove the car 250 miles, filled the car up again and parked the car for 2 hours. During the 250 mile drive I had NO problems with hesitation. When I tried to start the car after the rest, the car WOULD turn over, but would never start. I then let the car sit overnight. When I turned the car over on Saturday, it started with no problems. However, the hesitation had returned. Yesterday (Saturday), I had the fuel filter changed, and then put another tank of gas (premium of course), and more gas treatment. The car ran great last night (lots of power and no hesitation)! This morning I went out and the car WOULD turn over, but would never start. I have had this car for 3 weeks, and it has had a gas smell from the exaust since I have had it. I guess the smell might or might not be related to the starting issue. Could this be a bad fuel pump? Need new injectors? I will try new plugs in the morning. Any suggestions for me?

Thanks!

[MixMasterK]

Check the spark plugs for fouling, fuel pressure, fuel injectors.

[drew1]

Ramzel,

Is this CIS or L Jetronic injection?

drew1

[Ramzel]

FYI--I am a female. Don't rag me...but, I don't know. How can I find out?

Thanks,

Christina

[Bob's944]

should be L-jetronic

[Ramzel]

I just found it. Yes, it is L-Jetronic.

[Bob's944]

I can't claim to know the LJetronic sys at all, but it is electronic, so there might be a relay involved that is going bad. I'd look for that first, should be in your fusebox, hopefully labeled well for you to find easy, should be relay #8 in your car.

You also have a fuel pump relay that may also cause this, it's #19 in your car.

[This message has been edited by Bob's944 (edited 11-05-2001).]

[drew1]

Hi Ramzel,

Wasn't trying to make fun asking about CIS or L Jetronic. Some things are similar and some different between the two types.

The way the car won't start when hot, runs good in the evening, misses when warmed up, & smell of gas makes me think it might be running rich. But, it did not start one morning after sitting?

Since the system is electric, it is good to check connections when working on it. On a boy's 914, that wouldn't run right & he had a couple of shops look at, I lucked up into finding a bad connection on an injector. Bad vaccum hoses cause problems with injection, too.

One thing good to have when working on injection is a pressure gage. The fuel pressure has a lot to do with how much gas is mixed with air for the motor. On electric systems the pressure should be around 40 PSI so you have to be careful when working on it. A lot of gas can spray out hard & quick.

Checking fuel pump - One of the other responces said the relay was #19. Hook up the guage, & jump relay terminals 30 & 87 in socket to turn pump on. The guage should read a steady pressure above 40 PSI , I think. If not the pump may be bad. Cut the pump off for about 15 minutes. If the prssure has dropped to nothing in this time the check valve (on pump outlet) is bad.

Pressure regulator - close off the return line to the gas tank. Run the pump & pressure should be a few PSI higher than before if OK. If now your pump runs at 40 PSI when it was around 20 before, you have a bad regulator. Plug relay back in & start motor. Pressure should be around 30, Pull off vacuum line & see if it rises to about 30. A 928 may be like a 944 & have a dampner that looks like the regulator but is on the return to tank. Check this, too.

Check Cold Start Injector (think 928 has one) - Get a Clear plastic container, like a 2 liter drink bottle, pull the injector leaving the gas line hooked up. Put injector in bottle, Run the pump & see if it leaks. With cold motor, Plug the relay back in, ground coil wire with spark tester, & try to crank. Injector should spray a cone spray. If no spray, check wires & thermo switch. Do the same with warm motor & you should have no spray.

Injectors - Pull them & take them to a shop or parts store with equipment to check.Those things are what I would be check to start with.

drew1

ps: be careful the gas.

[This message has been edited by drew1 (edited 11-05-2001).]

[ae1969]

...here is some bedtime reading....

if you really feel upto troubleshooting your fuel injection system....

http://persweb.direct.ca/aschwenk/TroubleshootingtheLJetronicSystem.htm

good luck......

maybe start here....

http://persweb.direct.ca/aschwenk/page133.gif

Alex

------------------


86' 944
79' 924 (R.I.P)

[This message has been edited by ae1969 (edited 11-05-2001).]

[JonA]

The Jetronic systems can be pretty intimidating unless you have worked with them before and know how to read schematics and use a multimeter. But it is a good system and not prone to problems.
Air leaks can seriously affect performance. Check all vacuum hoses to make sure something hasn't fallen off. Check the rubber boots at the air metering unit and at the throttle body to make sure they are fit up tightly and shake them to make sure they are not opening up as the engine moves around. Check all electrical connections into the various components to make sure everything is tight and nothing has fallen off.
Beyond that you need a good manual and the patience to go through things systematically.
If you have any specific questions post them. There is a lot of experience among this group.

Jon Aborn

[Ramzel]

Thanks so much for the great input.

Christina

[fty]

distribuytor cap ..then check plugs then check coil...-chris

[adgx]

My son and I went to view, and ended up purchasing an 80 928 in beautiful condition a few weeks back. I was a little argumentative with the seller as I know porsches pretty well, and he obviously did not, though he said he did.We drove away with it for only 4 grand even. On the test ride it ran like a scalded dog, though I could detect some rumbling from the rear. Tube bearings or Cv joints I suppose. On the way home, I stopped at a traffic light and it went dead. It had plenty of gas, but acted as if it was out. It turned over fine, but would not start. We pushed it off the street (angrily) and tried to start it for a while with no luck untill I poured a little gas into the intake under the air cleaner. It started right up and ran perfectly for a few days untill one night when my son drove it to work, and while leaving for home, it stalled again. I had prviously told him to get a
can of starting fluid spray (instead of raw gas) in case it stalled again, which he used, and again it started right up. It has not happened again now for about two weeks. I suspect a fuel pressure problem, or relay problem, but the fact that you can squirt in the starting fluid and drive away seems to support a fuel delivery problem. I'm wondering if there is a technician who reads this post who has experience with this probibly common problem (like Roland?). Good Luck with yours, Christina, these are very sharp and well built cars!

[Ramzel]

Well, new spark plugs were put in and it still would turn over, but never start. I also tried the starting fluid suggestion, but no luck.

After all the turning over, the battery was draining. . . Last night we went to put a battery charger on the car overnight, when we discovered there was NO water in the darned battery! We added water and charged it overnight. The car started this morning. I have had no problems with it at all today. Lets cross our fingers! I'm taking her out on the town tonight!

I have a new rotor to put on, and the distr. cap had been on order, but has not come in yet.

Is it possible a dry battery could do all of this? I am pretty clueless on cars!

[maachan]

Hi.
My 924S with L Jetromic had similar starting problem, even staling while on the road. After few diagnostic checks, I suspected that the fuel pump relay is bad. But I could not confirm it. Worse the test I did on the relay out of the car proved it is OK. But I followed my gut feeling about the relay being bad, I changed it anyway. It was cheaper than I thought it would be, and a lot cheaper than the ECU I thought may be bad, too.
After the relay change the car is running fine with no problem at all.

I talked with my brother who is a mechanic in Japan about the problem. He claims for some reason relays from Germany has this kind of problems, it's ok out of the car but not on the car. He said a lot of times he could re-solder the old relay to bring back its performance, solve this kind of problem.

Good luck.

[maachan]

Hi.

For hesitation problem, check distributer cap and
rotor,
too. I had hesitation problem, too. The first sign of hesitation was about 6 month ago. And it progressed till last month. The engine stumbled at take off from the traffic lights. It felt like the engine was running too lean, starved for gas. Or may be way too rich. I was lazy to check it out, thinking it still runs. But one morning on my way to work, it stalled 2 times and I realized I cannot go on like this any longer. In the end I found my rotor's center carbon brush was worn too much that it was not making contact with the rotor, yet the car could run.
After the cap and rotor change, there is no problem of hesitation.

Good luck,
Maachan

[Ramzel]

Thanks all for the great input!

For grins, we changed the battery. . .turns out the previous owner had the WRONG size battery in the car. Intelligent, huh! Not enough cold cranking amps. We also changed the cap and rotor. Runs great now!

Proud to say I received my first speeding ticket. Too bad he hadn't caught me 10 minutes earlier. I was racing a hotrod Honda, something or the other. Kicked his butt, of course! I'm not missing my Mustang Cobra so much anymore.

So, the bad news is: the car is still running rich. I now need input on the O2 Sensor. Is this a job we can do? Or should we get a mechanic on it? How time consuming and difficult will it be?

Thanks in advance!

[maachan]

Hi,
If the O2 sensor is bad, the engine run richer than it should be.

Sometimes the faulty sensor could be disconnected and the control unit will compensate for it, thus making the engine run better than when it is connected. But not always.

Good luck,

Maachan

[drew1]

Glad you got going. O2 sensors can be stubborn getting out. You'll probably need penetrating oil & use antisieze on the threads when putting it back.

drew1