Inherited truck some years ago. It had been sitting for a while & once I decided to pay it some attention, it started up & ran fine. Occasionally the oil pressure gauge would drop to nothing, but I think that was just a short.

Front tank started overflowing gas about the same time a recall fix was issued. Dealer fixed for free but rear fuel gauge never worked after.

Anyways, turned it off one day & 30 minutes later it was dead. Put cables on it & nothing. After several tries, it started but gauges went nuts, idiot lights on/off, clicking from relays under hood & runs rough! I moved it out of the way & shut it off. It sat for a couple weeks after that.

Came back & tried to jump it - would spin but not fire. Put a new battery in & it starts. Truck runs rough. New plugs/wires/cap/rotor - no change. Temp gauge is dead (sender tests ok), ignition bell "ding" has become all but inaudible, and switching to rear fuel tank causes truck to die instantly.<--These things worked before the "meltdown".

Truck is (somewhat) driveable, but misses & is lacking power. Runs better accelerating & does not like low rpm cruising. Ran some Sea Foam through it & picked up a little power, but the problem remains.

Is the ECU toast? Where is it located? Any insight much appreciated.

Thanks & peace - Jeff

 

I'm assuming that your 90 is the same as my 91. The brain is in the passenger kick panel below the dash. The door chime on mine can hardly be heard too and I wouldn't think much about it. The gauges in these trucks were crap when brand new. Add some age and they are a real treat- few work right anymore. Most dash gauge issues are a result of a malfunctioning dash board electric regulator. If you have access to a code reader, yours is an OBD-I or the old reader, and pulling the codes stored will probably tell you exactly the issue. FWIW, I've already had the replace the brain cells in mine at 115,000 miles. It would run crappy and once it got to normal temp, would cut off and not run at all. Once cooled, it would start the process all over again. It was obvious that the board was toast by the smoked area. I also chased trouble codes for weeks trying to fix the issue and some of the codes kept coming back. That was before I inspected the brain box. But I think you'll find that your problem is in the fuel system though.