95 Ram Van 2500 Chatter

Hi all, I have a 95 Ram 2500 and it won't always start if it sits too long. I have to turn the key to the on position and wait 10-15 minutes, sometimes longer before I hear chatter coming from the ignition coil. I've change that but still no success. New batter, new starter. I have an auto starter on it and its about 2 years old. No problems with that unit and it still works. I heard that may be the problem but I don't see how.

There was a former posting explaining the exact problem I have, but it never showed the answer. Does anyone have any ideas on how to resolve this ? It sounds common.

Here's the old thread... My problem started as a nuisance and progressively worsened into a disabled vehicle. I have a 1994 Dodge B2500 Ram Van, 3.9 L, MPFI with 88k. A few months ago it would occasionally crank excessively and finally fire up. I found this got worse and more frequent. When cold, the fuel would take some time to prime usually about 10 - 20 seconds. Once hot, the motor would start on the first crank and continue to fire up through out the day. The problem only occurred when the engine was cold.

I have since replaced the spark plugs, wires, air cleaner, PCV valve, breather, distributor cap and rotor, and finally the fuel pump. I also tested the operation of the MAP, Crankshaft postion sensor, Camshaft position sensor, Throttle position sensor, and the Idle Air control. This did not fix the problem. It may have created a new one.

Now it takes approximately 2- 10 minutes to prime the fuel. A pressure tester shows 40 psi at the fuel rail once primed. Now, however the autoshutdown and the fuel pump relays "chatter" for several minutes. They toggle on and off very quickly - several times per second. While this happens the fuel pressure climbs and when it reaches 40 psi, the relays stop clicking and the ignition is enabled. Once the relays stop making noise , the motor turns right over and fires up easily. I tried to ground the relay PCM ground wire ( dk blue with yellow stripe) directly to negative battery terminal. This forced the fuel pump on, but would not allow me to start the engine. I assume this is because although I had fuel pressure, I had no spark. It would not fire until the jumper was disconnected and the relays were allowed to continue chattering until they stopped.

The diagnostics show a code 12 - PCM voltage and a 45 overdrive solenoid. I finally took it to the dealer who spent a few minute with it but once the tech realized I had installed an aftermarket alarm and remote starter, he would not investigate any further. I realize the wiring modifications could cause the intermittent power failure, but they're not new - they've been working fine for four years. And if it was the cause why would it only occur when the engine is cold? I have checked the wiring connections and all appear OK. The dealer said I would have to disconnect the systems before tehy will analyze any further. I am willing to do this but in the meantime, it now stalls,

I've been able to live with the starting issue. It only takes a few extra minutes to "prime the pump". Since this problem only occurs after teh van sits for a long period of time, I've spent weeks trying to troubleshoot it! Once the motor is warm it starts fine. But now,perhaps I screwed up something while troubleshooting, the engine won't accelerate smoothly past idle speed. If I give it a little gas it sputters rather violently and then stalls. If I give it a lot of gas it sputters and revs past the stalling point and then it runs OK. (Well I have lost a lot of power now, and I keep the van in the driveway until I can figure this mess out.) I have monitored the voltage coming off the TPS and it consistenly increases from 0.6vdc, when closed, up to 3.6 when the throttle is open. Even through the stalling point. It seems to be vacuum related although vacuum is steady at 17 in Hg. I relaize theis may be kind of low. It was 18 in Hg when I first started messing with it, but it's been rock steady the whole time.

I believe have two separate issues, although they may be related. I thought if I spent the money, the dealer five star expert techs would be able to tell me what the runnablity issue was with stalling above idle speed. Unfortunately they won't go past the starting situation.

Why am I stalling?

Reply to
jamesholland7
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Hello James,

Well, the good news is that the lady just picked up a Jeep -- and in the recent past at the Jeep NG there was a discussion about chattering fuel pump relays. I see you talk about the coil buzzing (haven't heard that since I was in Gramp's antique engine shop), but your pasted posting talks about relays -- so I'm going for the latter. I imagine the info applies since we're under the D-C banner. Check it out:

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Also, James, are you saying that the fuel pump doesn't kick on for the

1-second or so priming when you first turn the key -- so it doesn't kick on at all until the 10-15 min period has elapsed and the relay chatter begins? Typically you can hear it with the door open for a brief on-off cycle when you first turn the key from off to on. I think this info will help greatly for myself and others grinding this one up.

Jon

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Reply to
Jon

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