Electrical Problem

[krshome]

Ok, I have a 1988 911 it has a weird problem once in a blue moon after driving for a long time or at a DE event the car will not start. If I let it sit for an hour or two starts right up.. I thought that I might buy a Hot Start Relay but today went to start the car cold nothing. I can hear the ignition click but the starter does nothing Is there a relay that goes on the 911. I also have an old Car-Pro alarm that I know nothing about it's either a CPX-2500,CPX-2600,CPX-3500, and CPX-3600 I have read post with other car with this alarm doing the same thing I just don't know how to pull it to find out if it's the problem. HELP!

[DRACO A5OG]

Of Course you swapped teh DME relay, right? When you crank do you smell unburnt fuel it not I default to the DME relay.

Then check your CHTS (Cylinder Head Temperature Sensor) for proper OHMs per Bentley.

Then the REf/Speed Sensor OHMs.

One Pelican found his fuel filter was plugged a rarity. I think he remove the strainer on the filter and she purred like a kitten.

Jim

[krshome]

Doesn't get to the point of fuel smell doesn't turn over, starter not getting power. It runs great when it starts up.

[DRACO A5OG]

Oh I see, got it.

OK, no power to the starter, how old is the battery? Have you check the voltage? If you can get her started see what type of voltage your are reading.

Try jumping her, if she cranks over and starts there is your culprit.

Bentley has the wring Diagram

[JJ 911SC]

Had the same problem last year.

Next time it happen, try a "down hill/push" start.

If it start, time for a new (or reconditioned) starter.

[DRACO A5OG]

If it is the starter, try hitting the solenoid with a stick and mallet while trying to start her. solenoid may be binding.

You might want to check the voltage to the leads at the starter as well, make sure they are clean and tight for extra measure.

I actually serviced mine, cleaned and lubed to quiet her down to OEM.

[krshome]

Battery is new and good. I think it might be the starter I'll test tomorrow.

[DRACO A5OG]

Keep us posted

[bcketner]

I ran into this same problem and it ended up being the ignition switch,but first make sure all the electrical plugs near the ingnition switch under the dash are plugged in and fully installed as these have been know to get knocked loose.
Bret

[krshome]

Quick question. Don't laugh! The DME relay everyone talks about replacing/having an extra where is it located? Is it the one under the drivers seat? What are the symptoms of a bad DME? I have only had my car for under a year so I'm still learning. Thanks

[wildcat077]

Yes the DME relay is the one under the driver's seat ... Everybody should have a spare one in the glove box !

The symptoms are just what you are describing,basically it comes down to loose/cracked solder joints ...

Cheers!
Phil

[krshome]

Ok this is where I am. Battery is fully charged. When I turn the ignition everything works gauges, radio, windows, lights ect. When I go to crank it over all I hear is the fuel pump. I do not have an extra DME relay but I'm ordering one. Could it be the DME? From what i'm reading on bad DME relays the starter will still work but the car doesn't get fuel, my problem if its getting fuel but stater doesn't work. Could it be a simple as the starter is bad? I have to get my buddies over to try to push start it.

[HawgRyder]

If the starter is NOT cranking...then the solenoid or the wiring to it is suspect.
I would pull the starter and have it tested...thoroughly...have the shop put a load on it when testing.
I think the solenoid is probably getting too hot..perhaps the coil inside has a few shorted turns.
Bob

[DRACO A5OG]

With your buddy, get under the right rear wheel at the corner of the door. while your friend is trying to start her, use a 2x4 and a mallet to tap firmly on the solenoid.

Your solenoid may be binding as HawgRyder has referred to.

Check the contacts while you are down there as well and voltage on that yellow wire to the solenoid.

Jim

[krshome]

If the solenoid is binding is it time to replace the starter? No friends available today to help 4th and all.

[DRACO A5OG]

Where are you?

Not necessarily, it may just need servicing. Remember the starter is a wear part, the shavings of the bushing for the motor makes a mess and it may contaminate and get in the way.

When I took mine off it was filthy and no wonder everything was sticky and noisy.

But these days they sell life time warranty on them for either the Hi-po Starter or OEM type at FLAPS. Not sure what Pelican's offers on the Starter.

If you do replace the drop the starter for service or replacement. Trick is to remove the Heater Hose. it makes it much easier to work in there. When you put everything back make absolute certain all electrical contacts a clean and making good contact especially the GROUND. Oh yeah disconnect the battery for safety.

If you want to know how to service the starter search under my name DRACO A5OG.

[T77911S]

car alarms are notorious for causing problems. first you have some kid doing a hack job putting the thing in, then you are cutting the already overly stressed start signal to the starter. a lot of current is required to pull in the solenoid so anything that adds resistance reduces current.
i found the bad relay connection with a test light on my borthers 88. same problem, he thought he had a hot start problem. i tested the start wire at the starter. the light did not shine as bright as it should, or you can use a multimeter. check for 12v.
his turned out to be a lose crimp at the relay that disables the starter. i f it was me, i would not disable the starting or running of the car, just make it so the car alarm sounds. if you have crimped connections, i would also solder them.

you also need to clean all major battery connections, both positive and grounds. dont forget the ground from the body to the engine.

the ignition switch can also cause your problem.

he ended up replacing the starter and the ignition switch for a bad crimp connection.

[krshome]

Thanks everyone for the help, It was the starter. I swear if it were any other car I would have figured that first but all this talk about DME's and hot start relays really messed with my head. Plus the starter is so darn hard to get to for testing. I have ordered a extra DME relay because I really hate being stuck! Thanks again, Everyone on this forum ROCKS!

[dshepp806]

HEAT-related starts usually ARE the starter...

Glad you NAILED IT!!!!!!

BEST!

Doyle

[DRACO A5OG]

Hoorah!

Now go driver her