I have a 1990 250 van with a starting problem. In a nutshell: It is used as a Vermont-Florida commuter twice a year. It refused to start last fall and was towed a total of five times to various garages. It was cold here in October, but each time it was towed it would sit in a heated garage and then would start. When it finally would not start in Pennsylvania, the mechanic and I discovered the problem was in a solenoid on the throttle body (looked like a carburetor to me) It would not activate in the cold. We finally got it running and drove non-stop to Florida. I installed a new part in Florida and it would start every time. Fast forward to the return to Vermont. No start once the weather was cold. Finally I placed a space heater close to the intake manifold and after a half hour it started. The solenoid would not activate until the temperature warmed. The problem is not in the new part. There is something in the immediate area which is failing because of cold. What the dickens is going on here? A total of seven mechanics have looked at this...five of them Dodge personnel. I'm about to burn the bloody thing. Please help!!!!


Sixty-five hits so far, and no one has suggested the computer? C'mon, guys.

 

Welcome to DF. Will move you to the correct spot.

For future reference:
https://dodgeforum.com/forum/dodge-r...ead-first.html

 

I'm not sure its the source of your issue, but I assume the solenoid you are referring to the Idle Speed Control (ISC) actuator which needs to be properly adjusted.

https://dodgeforum.com/forum/1st-gen...e-problem.html

Does it crank at all when it won't start? If so, does it crank weakly? You could be unknowingly keeping a weak battery just good enough by keeping the engine comparment warm.

The computer (ECU/PCM/SBEC...) also can be finicky and function more reliably when warm (some resort to using a hair dryer).

There are a number of issues that could cause starting issues but I don't see as direct of a correlation to ambient air temperatures. It would be helpful if you knew you whether its getting spark/fuel if/when it cranks but doesn't start.

 

Your no start in the cold issue is caused by weak spark or a bad PCM. The first test is when it won't start, use a hairdryer to warm up the PCM, don't cook it, just warm it. If it fires up that's the problem, if it doesn't then it's weak spark. For the weak spark the ignition coil, the wires, cap/rotor, or spark plugs should be inspected to see which is the culprit.

 

I had just ordered a new computer before these answers came in. The vehicle cranked, had spark, gas. New ISC, dealer-adjusted as the instructions stated "by the manual" for adjustment. Vehicle cranked like crazy and had spark and fuel. I'm on my 90th vehicle and ordinarily do all my own repairs, but this one had me completely stumped. (all the mechanics, as well.) I think there is a hairline crack in the computer printed circuit and heat expansion closes it up. Thanks so much for the advice. I believe it was spot on. (I'll let you know if it didn't work.) Look for the van at the bottom of Lake Champlain if this doesn't solve it.

 

Just because it has spark doesn't it has strong spark. Recently I dealt with someone with a similar issue and he had spark too. He finally listened and removed the ignition coil to bring it in for testing. When he removed it he found significant cracking on the underside of the coil. Installed a new one and the hard starting went away.

 

I have an '89 which shares 95% of the same System

The connectors at the engine computer are prone to issues, especially if some "tech" at some point punctured the wire's insulation to test, and did not refill the holes with some rtv or liquid electrical tape.

I've had recurring issues with my 14 wire connector because of this, and at some point will need to get new Molex connectors and rewire the whole effing dang thing.

My point it, if it occurs again, the no start, try just wiggling the connectors and the wires leading to them at the engine computer.

Also taking steps to prevent rain, or wash water running down the firewall and onto such wires is good preventative medicine.

 

While it was in one of the garages I pulled the primary off the coil, and oil poured out. So...she got a new coil. Made no difference. The problem hasn't been spark. The ICS would not engage.

 

I'll inspect all wiring carefully while installing the new part. The entire area looks as if it has never been touched in any way, but...we'll see. This is something I never would have thought about. Thanks