New Parts 1994 Dodge Caravan CNG

[galactica]

I have a 1994 Dodge Caravan 3.3L V6 CNG. I lost my injector driver module to a big puddle of water. It is located under the left headling in front of the wheel. Unfortunately, for me and the world, Dodge no longer makes this part. I was told any module from either a V6 or V8 from this era 92-96 could be made to work. Can anyone help me? Contact me.


The Caravans, Dakotas and Full size vans of this era all used the same type of module. It was added between the PCM and the multiport injectors to compensate for the larger injector found in cng vehicles. Caravans were factory cng produced in limited qualities in 94-96. See attached pictures and diagrams. My scanner is also buring out.

[Curtis]

Re: New Parts 1994 Dodge Caravan CNG

Galactica (like the handle), I'm going to move this to the proper forum covering "Other natural gas vehicles", so others can find it.

That said, if the non-cng versions of the van are the same, it seems like pick-a-part, or a junk yard would be a good bet. If it's cng specific... you have a quest ahead of you.

[kidclarkey]

Re: New Parts 1994 Dodge Caravan CNG

Hey Galactica, My name is David (user kidclarkey) and I just joined. I also have a 1994 Caravan c/v and I found this site while looking for info to help me fix my van. Your post about the injector driver box was very helpful and I want to thank you for your post. It steered me in the right direction.
First of all, about 2 years ago, the van began to have a problem when the throttle was opened more than about 1/2 way. I checked the voltage at the throttle position sensor and found that as begin to move from idle to full throttle the voltage begins to go up, but, at about 1/2 way, the voltage falls off, so I put on a new throttle position sensor, but the same thing continued. I figured the problem was in the ECU and just drove it like granny. It ran fine, you could cruise the highway at 70, you just couldn't give it too much throttle. I think the problem is in what the Napa Auto Parts guy calls 'the body control module'. It's still an ECU to me.
Then the other day my van started running really bad. I checked the engine over and figured something was up with it electronically because compression and spark were all good, but while pulling plug wires to check for the dead cylinder(s) I found that a 4 out of 6 were weak. I then deduced that the problem must be with the injector controller, since the condition started suddenly, not gradually getting bad over time, which would have made me suspect something like injectors wearing out.
At any rate, I read your post with the photos and pulled out my injector control box. The cover was rotted and water was getting inside and all the screws were corroded. I got the remains of the cover off, carefully dug out the clear jelly like stuff they seal the circuit board with and found a lot of white corroded junk all around the edges. I carefully removed as much as I could and sprayed it down with contact cleaner and plugged it back in. The van runs excellent now!!! It still has the problem whereas you can't give it too much throttle, but while driving like granny, it runs excellent.
I then pulled the harness and connector back into the engine compartment, cut a piece of clear plastic from a blister package for a new cover and used silicone sealant to hold it in place. The box is now strapped to the top of the air cleaner. I plan to move it to a safe place (like my dashboard) later.
Maybe you can revive your box as I did mine. Also, I check with Napa auto parts and gave them the numbers. They said they could send it out and have it rebuilt for $300. I also got a price from Napa to rebuild the suspected 'body control module' of $200. I might invest in that someday, right now, I don't need more than 1/2 throttle.

[larrycng]

Re: New Parts 1994 Dodge Caravan CNG

Just looking through some of the posts I mised a long the way, especially being on the road.

Make sure you check all of the grounds in the computer system; engine to body, engine to battery, and especially the computer case ground and sensor ground circuits. Check them with an ohm meter on low range or better, check for voltage drops between the computer plug and the battery and the others mentioned above; the voltage drops should be less than 0.1 volts (1/10 of a volt). If the voltage drops are greater than 0.1 volts, you may find the voltage signals taking alternate paths to ground or to the computer (sensor signal ground).

If you think these voltage drops can not be criticaly, GM many times requires less than 0.05 volt drop (especially on Allison transmissions). These voltage drops should be checked, especially where there corrosion; snow country and costal zones. I have in some cases run an extra ground wire from the battery to body, one to the engine, and one the computer case mounting bolt. -- solved some real nasty problems.

Larrycng

[galactica]

Re: New Parts 1994 Dodge Caravan CNG

Thank you for the replies!!! I found a used injector driver module and sealed all the edges. I might move it inside the engine compartment. But, my van works good now. I was told not to worry about the tanks, just keep an eye on them after expiration date. Hopefully, this summer I will buy a newer cng van. Thanks. Terry