Hey gang,
Need a little help with stalling issues. I've searched/read this forum extensively, learned LOTS of good info, but can't find the exact same issues/circumstances I'm facing.

My van:

• 1994 B350 Ram Wagon Extended, 5.9, 88k miles.
• Replaced the crank sensor and rotor when purchased 4 years ago with 55k miles.
• Have since replaced the pads and calipers and water pump. Solid performer.

Previous ECM issues:
Twice quit running while driving, both times blew the ECM. Now keep a spare on hand.

Current issue:

• Had been running fine all day, went out to dinner. After dinner, drove about 3 minutes and it suddenly quit while running.
• Tried to restart, and it turned over but wouldn't fire. (Just like previous ECM issues.)
• Was late at night, so had it towed home (took couple of hours). Figured it was the ECM again, so I plugged in my spare. Fired right up.
• Just to double-check, plugged the old one back in. Fired right up. Hmm.

• Next morning it fired right up again, so I took off for some errands. Drove about three minutes, and it died and wouldn't restart.
• Switched ECMs and still wouldn't start. Left it on the side of the road and walked home.
• Did some research on here, walked back to van with a plan of action (couple hours later). Just for kicks, tried to start it. Fired right up, so I headed for home.
• Died again (~3 minutes) as I pulled in the drive. Wouldn't restart.

Did more research and followed some troubleshooting advice.

• No visible wire issues under the hood.
• Cleaned and greased ECM connections.
• CPS wires are fine.
• Getting spark.
• Pulled the codes - 12, 37 (baro-read solenoid), 55.

By this time, it had sat for awhile, so I tried to start it. Fired right up. Ran for about 5 minutes, then died. Wouldn't restart, but there was a strong smell of gas.


The current state:
After it sits for an hour or so, it starts right up. It will run idling for 5-10 minutes, as soon as you press the accelerator, it dies - followed by a strong smell of gas. Have repeated this several times.


The diagnosis?
Talked to my mechanic, and he thinks it might be the fuel pump quitting after it warms up a bit.

• Does this make sense?
• Anything else I should try before dropping the tank and installing a new pump?

Thanks for making it this far, and for any suggestions.

StanO

 

It's a bad ignition coil.

 

maybe the ASD relay? although i don't have much experience with this it seems like that's a common issue. not sure if getting spark rules this out though.

 

92 B250 -- same symtoms as yours a few yrs back

replaced ecm and all is well

 

Thanks guys, for your responses. My thoughts . . .

alloro and dag: it runs for a few minutes, then dies when I advance the throttle. After it dies, I'm still getting spark. How can this be the coil or ASD?

nibroc: I replaced the ECM with a new one, still have same symptoms. Any other thoughts?

 

Having spark is not the same thing as having strong spark.

 

You state having a 1994 not a 1994-1/2 model year correct?

The 1994 is the older engines PRE-Magnum. 1994-1/2 started the Magnum engine era.

ECM was pre-Mangum engines. PCM is Magnum engines. Thus, not knowing the type of engine you have makes things difficult to decode the problem.

And yes, my Magnum engine will do just like yours on a bad coil. Also, with a coil like that, no engine codes are thrown.

 

likewise, a relay can fail intermittently

personally, i'd throw another relay in and coil. both pretty cheap

 

Update #1:
Went ahead and ordered a fuel pump from Amazon on Friday ($65 delivered vs. ~$175 in-stock locally). While waiting on arrival, I dove into troubleshooting the coil and relay.

First unplugged and visually inspected the relay (looked good), so cleaned the contacts and plugged it back in . . . figured I could replace later if needed - simple things first, right?

Visually inspected the coil and it LOOKED okay when installed. The contact post was a little dirty, but no big deal. Went ahead and removed it to bench test it. Got it off, turned it over and OOOOPS! Pretty big crack on the underside. Houston, I think we found our problem!!!

Installed a new coil, and it leaped to life immediately - good sign! Pulled a plug to check the spark, and it was WAY bigger and brighter than with the old one.

Left it running for 30-40 minutes to see if I could replicate the "stalling when warm" issue, and couldn't. Woohoo!

Alloro, MAD PROPS to you for nailing this right out of the box! I guess I'll be returning the fuel pump I ordered, and am glad I don't hafta drop the tank. (Fingers crossed.)

And I need to remember a big lesson I learned from wrenching on my vintage, air-cool racebike: AIR, FUEL, SPARK - CHECK THE EASY THINGS FIRST.

I'll try to post back another update mid-week, hopefully with no further issues.

 

Considering you placed the fuel pump order on Friday, maybe you can cancel the order before it ships out.