Ok so the van computer is in, and I have no more code 27! I took the truck for about a half hour drive on the highway and in the city and there is no more vibrating and shaking. The idle is silky smooth and the stalling is mostly gone. The idle still drops a bit when you release the gas quickly but it seems that the more I drive it the less it happens (computer is learning?) And it managed not to stall while pulling into my driveway where it always did the worst.

Like I guessed I'm leaning towards the computers being a weak point in these trucks, and replacing them is a much more likely solution than bad injectors or wiring. I'm so happy I fixed it!

 

So I went to start my truck this morning. And it cranks but won't start. After about a minute of cranking, I put the pedal to the floor and it started but I wouldn't say it was running. Sounded like absolute coughing sputtering crap, wouldnt rev past 2k rpm and would die immediately when the gas is released.

I'm wondering if the new junkyard computer I put in is bad? I'll try the old one when I get home. I've heard mixed opinions on whether or not the 94 computer is compatible with my 92 truck, but it ran great for a week so I don't see how it would decide not to work all of a sudden.

This sucks because I was supposed to take it in for some much needed exhaust work today. Guess it will have to wait. Any ideas?

 

In my opinion this points to it not being the computer, unless there's something in your wiring that's frying the computer. The fact that it ran great for a week is a good a sign for the computer.

Just out of curiosity, what would happen if you reset the computer at this point with a battery disconnect?

 

I put the old computer back in today. Truck started easier but still had to hold pedal to the floor to get to start. Wouldn't idle. Had to keep on the gas to stop it from stalling. It smelled VERY rich. I ran it like this for about a minute hoping it was flooded and as soon as it burned off the extra gas would be fine. Not the case. It's strange how swapping the computers would make a difference but not fix the problem. There must be something else going on here. It's too cold outside still to spend a lot of time out there troubleshooting it. I'm glad I have another vehicle to drive in the meantime!

 

So it finally warmed up here and I went out to play with the truck and it started first try but wouldn't idle unless on the gas and ran rough. Did this until it warmed up and smoothed out and now seems mostly ok. Only thing I can think is maybe a frozen fuel line?

I also replaced the pcv valve because when I removed the hose the truck seemed to run better, although idled too high. Once I replaced it with a new one it was same as before and drops the idle too low when the throttle is released again. I know it's not the iac valve causing this what else could it be?

 

Try the Cam sensor. In fact it was called the switch plate in the materiel I was reading when I replaced it. It is the sensor in the distributor that tells the injectors it is time to inject. You'll see a pair of wires going out the distributor down the back over the tranny.
I don't know how to test it or to diagnose your issue beyond finding codes.

 

I would first check the coolant temp sensor.
Purchase a Multimeter and backprobes. (or any sharp conductive item, such as a needle) that you can insert into the back of the plug, where the wires go in.)
Then, check the voltage across the two wires while the engine is cold. Then periodically check it as the engine warms up. You should see a steady change in voltage as the engine warms. Or if you only have a multimeter you can unplug the sensor and measure the resistance. But this will trigger a check engine light and might stall the engine.

Another thing I noticed is that power for all the sensors first goes through the throttle position sensor. I think it is unlikely, but its easy to check. With the ignition off, unplug the TPS and measure the resistance were power goes in and comes out. Should read almost no resistance.

Good luck and keep us posted

 

looks like all the minor stuff is on hold because the computer went bad on me again. Long story short it won't start when it's cold. Took computer inside and warmed it up, plugged back in and runs great. Hope I can find another at the wreckers this weekend.

Also got a Dynomax super turbo muffler with a MagnaFlow 3.5 in stainless tip put on to fix up my leaky exhaust. Not too loud but still has that nice v8 rumble! Pics to come once I wash the truck!

 

So, got another computer, this time out of a 93 ram 5.2. No cold starting problems, but now the truck has less power, bogs down at wide open throttle, so I'm going to return this one too. Hopefully 3rd times the charm this is getting old!

On the plus side I fixed my power windows, locks, mirrors, radio, and interior lights! Turns out 6 wires in the drivers door jamb were cut (worn from repeated opening and closing of the door) and the insulation was starting to get cut on almost all of the rest of them! It kept blowing the ignition off circuit (IOC) 5 amp fuse in the engine bay every time I tried to use the mirrors. About an hour with a soldering gun and electrical tape and it's all back together and working like new!

Also the truck just failed it's inspection. And I've got a bunch of work ahead of me. Front shocks, ball joints, valve cover gaskets, power steering hose, bump stops and rear brakes were all just ordered from rockauto and hopefully will be installed before the end of the month!