I agree w/ you 100% about the vibration possibly damaging the PCM.

That van takes a beating from the audio system. We have killed windshields and ripped foot long gash in the roof in the past, had to weld that back up and sound deaden the hell out if it. And its only going to get worse. In that video and most of the others, the system was only seeing around 8kw. We are going to ~20kw very soon.

I will look into dampening the PCM mounts.

 

Be sure to add a ground strap from the PCM case to ground after installing the (presumably) rubber dampers.

 

My '89 ecm case is plastic, are newer ones metal?

 

Yes, they are metal, possibly aluminum.

 

Yes, this model van has a mainly cast aluminum case.





Well, I got the van back 2 days ago.
When I picked it up, the doghouse was just sitting there loose in the cabin. I clamped it in and the van cranked right up. I was happy...until I drove about 200ft. Noticed a hiss/whistle...pulled the doghouse, and the air box over the intake was not even in place, the bolt that holds it down was just laying on top. I repositioned the airbox and tightened it up, good thing I stopped in the parking lot before getting on the interstate, or I would have lost the bolt.

...ok...all should be good ???

well.

I got about a half mile down the road, the brake and ABS lights on the dash lit up.
Um..ok..sure...I kept driving.

Got about 5 blocks from out shop, caught a redlight. Sit there, van idled low. Light turned, I try to go, van spits, sputters, nearly dies, then catches up after about 8seconds.

Its done this attempted stall 4-5times in the last 2 days. With less than 40miles of travel since I picked it up from repairs. Limped across the lanes from the turning lane today at about 2mph when I came back from lunch. Hasn't died completely, just wouldn't rev up and gain speed, then catch back up in 8-10sec. Each time it has been after running steady speed for a mile+, then hitting a redlight or turn.

That is how my whole problem originally started...stalling at redlights, then it just all down hill until it wouldn't even run, then I towed it to the dealership.

I guess I'll check the plugs tomorrow.

 

The ABS light coming on, if not brake related, could be a bad engine/ firewall ground. Have you checked resistance between negative battery post and clean metal on the engine/frame/Firewall?

The sputtering could be a lack of fuel pressure.

Perhaps your audio system has wreaked havoc with the fuel pump, or the wires leading to it. Perhaps the fuel pressure regulator on the pump.

Does the amount of fuel in the tank have any effect on the driveablity issues?

 

Fuel pump/pressure was checked at another local shop...steady 45-48lbs.
Fuel level doesn't change performance.

But, since driving another day...the engine is acting better. Didn't try to stall at all today. I'm going to replace the fuel filter and plugs/wire though.

Also, as for grounds, it is running on the stock alt and optima batt for now. But in the car audio world, alot of high powered systems (over 150a current draw) do an upgrade known as the "big-3". That is upgrading the batt ground, engine grounds, and alternator to batt charge cable to 1/0ga wire and cleaning the grounds to allow for better current flow. The van had this, but is running on stock for now. I will reinstall the 'big-3' very soon. In many cases, you will also upgrade the grounds in many places, not just batt and engine. You leave the stock grounds in place, just add the 1/0ga.

 

Well, I'm glad it behaved for you today.

Many years ago when I was chasing down what turned out to be a failing ECM, I added a 4 awg cable from the engine to the frame.

Mine is a camper Van, and I have a 130 watts of solar and 2 Crown group 27 deep cycle flooded house batteries, and one engine battery, but the biggest load besides the starter is the blower motor on high, then the high beams/parking lights/ air compressor ect, so I don't really have the need for 1/0 gauge cable.

I do have 2 agw cable between the engine battery to the house batteries and manual Guest switch.
4/0 cables between the house batteries. In addition to the pathetic stock 8 awg charging circuit, I added 2 more 4 awg cables from the alternator to the Guest Boat battery switch . I also upgraded the alternator ground wire from 8 to 2 awg, and added another 4 awg cable from the alternator ground post to the frame.

All my grounds run through a 500 amp shunt for my battery monitor, It was this monitor which showed me how pathetic my alternator output was/ is at idle speeds. I have seen 40 to 140% more amps at higher rpms with my wiring upgrade, but Idle speed amperage, when hot remains pathetic.

I am going to make a heat shield for between the e manifold and alternator, and I am going to order a smaller alternator pulley, but that is on the back burner until I rebuild my suspension.

Please stick around after you get your driveability issue worked out. Many here can use your electrical knowledge.