Just need a quick response. I just installed a new ECM in my 94 Dodgevan B250. Before I reconnect the negative battery cable, I wanted to know if there are any checks I need to do? Or after I connect battery are there any checks I need to do?

Before I replaced ECM the only way to start my van was to put a hair dryer on the computer for a while or heat up engine compartment area with space heater or use an inline block heater overnight when it was 30 degree or below. But I must have overheated the ECM too much and wouldn't stay running anymore, and then I think I completed fried the ECM when I took it out for part # without disconnecting negative cable from battery. So now that I have new computer I want to make sure I do the right things. It's now connected to van without negative battery cable connected. Just waiting for a response from someone before I go any further. But need to have it running soon hopefully.

 

Make sure it is grounded. Mine has a ground wire co,ming off on of the bolts that connects it to the firewall.

 

No ground wire. Everything connected to frame is plastic. ECM is completely enclosed in plastic also. So I guess the harness and pins must provide the grounding?

 

I'm screwed!!!

New computer makes no difference for newest symtom of van won't start. Could something have fried with bad computer?

Van just turns over trying to get compression. I get all kinds of vacumm hissing and a rich smoke if I keep cranking out of TB. I'll check for spark and fuel pressure again. But this symptom is different than when the weather is too cold. Before there was no spark or pressure. This is the latest problem I have when I thought heating up ECM too long and barely making it home then after I unpluged the ECM with negative cable connected and I thought I fried it. Since it would no longer start anymore.

Could it be possible I have a bad ECM? It was damage. The plastic anchor on it cranked and I noticed a small crank in the plastic vent. Very small, didn't look too bad. And I wouldn't think the I'd have the same symptoms if it were a bad ECM. Frustrated at this point. No ride sucks. Do I need to reset ECM? Or could the cat have gone bad that quickly causing the 2 symptoms I talk about? Stalling out for a day then not starting at all?

 

Sorry about that last post. Frustration set in. I 'm without a ride now for a week.

For anyone who hasn't followed my Cold weather, no start thread, here's the low down. Van, prior to last week ran great except when temperature dropped below 30's. At that point it had no spark or fuel pressure at rail. IF I heated up engine by either using overnight block heater in line with coolant lower hose or using space heater pointed at engine or as suggested by someone using a hair dryer pointed at ECM, my van would turn over and run great. Depending on how cold it was it would either have no problems rest of day or if too cold I needed to restart engine every 3 or 4 hours (this would happen at temps of 20 and below.) So being hair dryer on ECM would work, it was suggested computer was on it's way out.

Now for the change of symptoms. Thanksgiving night I needed to heat up ECM to start van. I have 10 minute ride home from family get together. Just before getting home van starts choking real bad and bucking. Barely made it home. Next morning using overnight heater van started. Went to store and again barely made it home. So I thought ECM was getting worse. I unplugged it to find part # and forgot to disconnect negative terminal. After replacing old ECM and trying to restart this newest problem started. Van wouldn't start. Temps were warm outside and I could hear compression going on whereas in cold weather I got none. Finally started but it barely stayed running. So now the problem has gone from running great in warmer climate to not starting in freezing temps and progressively being harder to start the colder it gets. To not even starting in warm temps anymore. The same symptoms I got Thanksgiving night driving home and coasting into driving from van choking and bucking when stepping on gas pedal are now the same symptoms I have at trying to start van any time.

I just replaced ECM with a new one from autozone. Upon receiving it, I notice the plastic anchor area securing ECM to firewall was cracked and a very small crack on vented plastic cover. I guess it got dropped or banged up some how. But I fixed the anchor and had secured it to firewall without any problems. I doubt new ECM would give me the same problems as the old one did, which is what happened when I tried to start up van today. New ECM may have corrected the original problem of no start in cold weather. I'll find out when it gets cold possibly tomorrow morning. It's been warm here lately. I can tell the difference the way the van cranks over by the lack of spark when cold. Now I do have spark and van will actually start briefly if I give is just the right amount of gas.

I've read about the catalytic converter causing these symptoms here. But it happened so quickly that I'm not so sure this could be it. From running great when warm one day to not running at all within 24 hours. I would think it would be more gradual.

Hopefully I explained everything better in this post

 

Just curious, pull your distributor cap and look in there. Make sure that all the wires for your distributor are still sordered together under the cap. We had a '90 blazer that did almost the same exact thing at the shop. Cold, no start. Warmed up, would start but ran like crap, like timing was way out. Turned out to be the distributor. Hope this helps.