Hi everybody,
thank you for having me here - I've learnt already a lot reading this forum and I'm not gonna stop

I have dodge ram b250 conversion van - 5.2 magnum with automatic transmission. However I live in Poland and my van is quite an exotic piece of a car. It has only 65K miles and works fine - as long as it is cold. It starts fine, I can rev it high and everything seems to be fine. Transmission shifts smoothly and it runs 70 and even 80 miles per hour without effort - but after 2-2,5 miles, when it warms up, engine starts to backfire and it goes 20-25mph tops. I cannot rev it, because if bacfires and fires in the exhaust, but even then (warm) it starts perfectly fine. There is noone who can help me - you are my only hope now.

edit:
this is b250 ram van, it has no "check engine" light, so I can't read codes (unless there is any other way?) and I don't know how to use DLC - couldn't find any scanner with corresponding plug

 

What year van?

I suspect the fuel pump is weak or the ignition coil is cracked.

 

Hi, it's 1994 dodge ram van (conversion van - high roof, 7 places)

Is there only one ignition coil, or eight? Any way to check the coil?

 

There is only one not eight. Around here the auto parts stores have a machine to test them. But that doesn't always tell the tale since, such as in your case, when cold the coil is fine and fails only when hot. Assume of course the problem is the coil.

 

Hi,

I have ordered new coil, new O2 sensor (NTK 23023 - ok?), and new coolant temp sensor - is it hard to replace the last one? Should I do it from the inside of the van, or from under the hood?

And one more question: I don't have the "check engine light" - I mean - it doesn't light up. Can you tell me, where to look for it? Or - should I have it in 1994 dodge ram van b250?

 

There are 2 coolant sensors, a 1-wire one for the gauge and a 2-wire one for the PCM. The 2-wire ones is a few inches away from the thermostat housing, towards the passenger side. Remove the alternator and it's pretty easy to change.

 

thx, I'll (hopefully) tomorrow.

Another problem - no check engine light - and I mean it never lights up - neither while starting, nor by key-dance. Bulb looks fine, I replaced it with blinker bulb which is good, because blinker arrow appears, and still "check engine" didn't light up. Where to start? What to check?

 

Between that and the backfiring issue you could be looking at a failing PCM.

 

Is there any chance I can test it? O2, coil and temp changed, engine backfires when warm - sometimes right quick, sometimes after 5+ minutes.

 

About the only test you can do is before you start it in the morning and it's cold, heat up the PCM with a hairdryer. Once warm start the engine, if it backfires right from the get go then the PCM is likely bad.