911 Won't Start

[mcedata]

Hello all, looking for a little advice. I have a 1989 911 that I've owned for 5 or 6 years, and it's always cranked right up and runs like a champ. Due to some health issues, I left it sitting in my garage for several months without driving it; usually, if I don't drive it much, I crank it up and run it up to temp every couple of weeks. So, I tried to crank it up last week and, though it cranks just fine, it won't fire up. When I turn the key on, I can hear what sounds like the fuel pump crank up..a hum from underneath? One unusual symptom; I have a phone wired into the electrical system. Normally, when the ignition is turned off, the phone turns off. I noticed today that the phone stays on, even after the ignition is turned off. Coincidence?

Anyway, how do I start to unravel this mystery? Thanks for any suggestions.

Steve

[OsoMoore]

Hey Steve, welcome to the forum! Our 911's don't like to be "warmed up" without being driven - I was advised to always get in and drive right away (but keep rev's down until temp gets up).

I suspect the regular starts without actual driving are the culprit, but I'm not sure exactly how. Someone else will surely weigh in.
Also, posting pictures brings lots of extra views!

[T77911S]

first thing with any no start is to check for spark, since that is the easiest thing to do.

[kidrock]

replace the DME relay under the driver's seat. If this doesn't solve your issue, you will need to test for fuel and spark.

Before any further advice is dispensed, you are hereby mandated to provide all Pelicans with a photo of your vehicle. (LOL, just kidding....but please do post a photo.)

[mcedata]

Thanks, guys, for the feedback. I do have a spare DME relay, and will try that first...as soon as it's a little warmer in the garage. If that doesn't work, I'll test for spark. Testing for fuel...am I correct that I would have to get the car up on jack stands and check the output from the fuel pump? Or is there an easier way that doesn't require working underneath?

Steve

Pic per request...

[ivangene]

you can "jump start" the fuel pump by running a power lead to the fuel pump fuse - just listen for it to run...simple

I suggest letting it sit without starting while in hibernation

[kidrock]

Steve,

Replacing the DME relay is almost as simple as replacing a fuse. It takes a 10mm wrench or socket and about 5 minutes of your time.

Checking for fuel is as simple as disconnecting one of the rubber hoses to your fuel system (I prefer to disconnect a hose into the Idle Control Valve), spray Quick Start into the hose, quickly re-connect and turn the key. If the car starts then dies, then you have a fuel starvation issue.

If you have a timing light, use it on a spark plug wire to test for spark. I prefer to pull a plug wire from a plug, install a spare plug into the end, then I use a jumper wire with one end attached to the base of the plug and another end attached to a good ground. Have a helper turn the engine over while you observe the spark plug for a good, strong blue spark. If you have no spark, then you will need to start testing sensors and such.

But before you do ANYTHING, you need to swap out that DME relay with a known good relay.

[mcedata]

OK, thanks for all the additional suggestions. I swapped out the DME relay for a new one, and after some spittin' and poppin', it started up, lots of gas fumes, smells like a choked engine. EXTREMELY rough running...obvious that a couple of cylinders aren't firing. And that phone still stays hot even after the ignition is turned off. Beginning to suspect the ignition switch.

Noticed also that the battery, which is a new Interstate, drained from fully charged to dead over two days ending yesterday, so something is causing some, or all, of the circuitry to remain hot after the ignition is turned off. I think that issue is not solved, since the phone stays hot after turning off the ignition, and it didn't do that before this problem began.

Guess I'll start checking plug wires and such to see if I can find anything obvious. Also charging the battery again to see if it discharges right away. Any suggestions welcome.

Thanks,

Steve

[T77911S]

rats chewing on wires?

[Chuck.H]

The drained battery is the first place to start - you can pull fuses one by one to try to isolate a circuit that is drawing the current.

The rough running condition sounds like a head temp or AFM problem, but I wouldn't address those until the dead battery issue was solved.

Chuck.H
'89 TurboLookTarga, 343k miles

[camperman-x]

Had something similar just happen. ‘Gummed’ up’ up solenoid on the starter. After running fine all day yesterday didn’t start in cool weather. Solved with space heater pointed under passenger rear at starter area.

Just replying to old posts to help out =)