I just bought a beautiful 1994 Dodge B350 5.9L with 46RH tranny with 80k miles. Now I cant get it running without stalling while driving or idling. When I first bought the van I drove it 250 miles from Dallas to Houston with no issues. I installed a new stereo and it started to have problems (the previous owner kept his headunit and all I did was put a new one in). I took the stereo out and started to diagnose. It was stalling while driving (flame out) and wouldn't start back up until after it cooled down. I replaced the ignition pick up in the distributor and the crankshaft position sensor and it stopped the stalling. I thought I fixed the huge headache and I drove the van another 300 miles out to my property and back to Houston to go hunting with no issues and now it is stalling at idle and when slowing down to stop. I got stuck about 30 mins from home and was able to get home by keeping rpm high when slowing down and when stopped at red lights. It was fine on the highway with the cruise control on while trying to get home. Fuel pressure at rail tested perfect (39psi) and replaced IAC valve at Autozone. I can't hear any vacuum leaks and I cleaned the PCV and made sure it wasn't plugged. No improvement. Van is giving codes 12 (batt disconnect), 37, and 55 (end sequence) when doing key test for CEL. Van has new starter, TPS, ignition coil, Crank pos sensor, ignition pick up, spark plug wires, spark plugs, and IAC. The fuel tank was just dropped and cleaned and a new inline fuel filter was put on. When I look into the throttle body it looks fairly clean like it was done recently(no standing oil). I don't know what to do next. This is my first Dodge and I am certainly no mechanic but I'm definitely learning and very interested in learning more!

1. Any advice?
2. Shouldn't my key dance test be throwing more codes if Im having all these issues and should I suspect the PCM/ECM being bad?
3. Anyone have detailed diagrams of this engine in exploded view? (I cant find it!)


Thank you in advance for any help!

 

The autozone IAC is only going to contribute to the problem. These engines just don't like the aftermarket sensors. Replace it with a mopar unit, and clean the throttle body really well. (leave the battery disconnected while you are working on it.) When you have it all back together, hook the battery back up, turn the key to On, not start.... count to ten, THEN start the motor. PCM should then figure out the new part.

 

Well like an idiot I tossed the original IAC, crankshaft position sensor, and ignition pick up... Also, the original owner who replaced the ignition coil, starter, and TPS used aftermarket parts as well... Should I now replace all those parts with OEM MOPAR parts??? $$$$$$$.....

 

I would at least do the Mopar IAC, if it runs fine after that, leave it as is. If you still have issues, cam and crank sensors would be next on my list. TPS doesn't *seem* to be quite as problematic....... (I have an aftermarket sensor on my truck...... without issues.)

 

Hmmm The problem is that I was having all these issues before I put the aftermarket IAC on from autozone and after I put on the aftermarket crank position sensor. Now I am reading that most of the time an aftermarket crank pos sensor wont work right with these PCMs and I need to go OEM for that too.

Anyone else have any info on this topic?

Thanks for the help!

 

If replacing any of the sensors it's best (by forums consensus) to use the Mopar parts as HeyYou has said, can be found a bit cheaper online (amazon, ebay, rockauto.com) or pay the dealer price

I've had the wanting to stall, (one foot on the brake and one on the gas coming to a stop) and same on take off type symptoms like you describe when the iac was failing in my 99 5.9 a while back. The stalling out then having to wait before it would crank up and start was fixed by replacing the crank sensor.... I know you've already replaced both but did you try to cleanup the connectors with some electrical spray cleaner, dap a little di-eclectic grease in the pin connector and jiggle/ check closely the wiring to each sensor?

Just a thought but here n We've all done it, but there was one guy on here not too long ago, maybe a few months, who had replaced his pickup coil and would start sometimes then sometimes not. he could jiggle the harness and would start. He found that he hadn't plugged the connector completely in, when he did, no more problem.

One question since I'm here editing, when you replaced the iac, how did the orifice look clean or was it kinda black or somewhere in between? just spraying some cleaner in the throttle body may buy some time but taking it off and removing the sensors and giving it a thorough cleaning is going to benefit you more

 

Thank you for the response! Im going to get in there and clean the connectors tomorrow. The connector for the pick up is def plugged completely in. Also, the IAC wasnt too dirty but I thought I'd replace it anyway. The orifice where it was plugged was also a little dirty but carb cleaner inside and out took care of that. The previous owner told me that he had the throttle body cleaned and it is looking pretty good to me... Also, I inspected all of the wires that I have access to and they are all in really good shape for 80k miles. The whole engine/engine bay looks great for 80k miles.

 

Update: Cleaned all connectors and put everything back together again. No improvement. Picking up the OEM Crank Position Sensor from Dodge dealer today and will put it in and see if the one I got from Autozone was a dud. Ill let you know if this fixes it so that others can hopefully read my thread and get help if they are having the same problems!

Thanks!

 

Keep us updated.

 

Put in the OEM MOPAR crank pos sensor today and it fired up but stalled during idle after 2 mins. pulled center wire off distributor and threw in new plug to check spark right after and it is yellow/orange. Pulled out plug from cylinder to check it and it has no spark...

headed out in a bit to get new ignition coil... any advice on brand if not going OEM?? Looking for OEM at the moment but just in case I cant find it...