944 no start

[DAK47]

Hi hope someone can help with this consistent issue. My 85.5 944 does not like to start on damp, or rainy days, almost no tach bounce. I open the hood push it into the sun and breeze and after a while it starts. In Michigan now heavy dew evening and morning same problem??? I switched out the DME with another car no help. The car did sit outside for 7 or 8 years until my son replaced the clutch.

[jjeffries]

Dak, welcome to the forum. You'll need others with more Motronic skill than me, but generally speaking and based on the car sitting a long while, I'd be identifying and cleaning all grounds in and around the engine bay and on the motor itself, some of which may have been disturbed during the clutch R&R. I'd also clean all the Bosch connectors on the engine management system (dont lose the clips) ... anything electrical. Do you know how your son dealt with the reference sensors while he had the car apart ... did he have to reset their adjustment? Also, a hard start (crank but no catch) in damp weather might point to some old HT / spark plug wires and distributor cap & rotor. What I guess I'm saying, beyond the Ref Sensor question, is give the car some careful TLC targeted to the engine's electrical system. There's plenty more to check, but this would be one place to start and if you plan on keeping the car, or have empathy for whomever will have it next, it will be time well spent. All this kind of work really costs is your time.

Also standard caveat: how are the fuel lines, from tank to motor and back? Many a fuel-injected 80's German car that hasn't had its rubber fuel lines replaced has burned to the ground.

Google Clark's Garage and look at the online manual tab for an amazing how-to resource, including troubleshooting. On YouTube, look for Edredas, a likeable fellow who has many 944/924S-specific instructional videos, including for no-start/reference sensor.

Best of luck to you,
John

[kljfamily]

Does your have the DME (computer) rest in the footwell of the passenger side?

If so check under the battery to see if there are rust holes that are letting the moisture/water get down to the DME.

[DAK47]

No, my dme is in the fuse box under rear of hood driver side. I am trying to find out where all of the grounds are at as that sounds perfectly logical. Raining today tach will not even bounce.

[DAK47]

When it does start the gauges jiggle around a little not steady, ground somewhere?

[DAK47]

Whoops, my fault, I was thinking of the DME relay in the fuse compartment. I do have the car under a carport so no on water leaking into passenger footwell, just the dampness?

[Ernie944]

Welcome aboard DAK47,like mention by jjeffries I will start by cheching all the main ground....see pic Then check insde your distributor cap if there is acculumated dew in there.It will also be a good idea to spray your ....dist cap ...all sparks plugs wires ...coil ect ect with this stuff see pic sure will do the job for some 20 years I've use Gunk & was very satisfy with the result.take care & let us know how your doing.