1) Using your VOM to pull codes from the connector behind the glove box. If you have no pulses, but just a solid 12 V, the ECU is bad.

2) Assuming you don't see the above, then the next step is to remove the ECU (it's in that box underneath the dash on the passenger side). Disassemble the box so you can see the circuit board and look for the large power supply capacitors (little blue can-like things). If there's brownish goo underneath/around them, they are leaking and need to be replaced ASAP. There's a good how-to out on the web -- you should be able to search for this, or I think Ray might have a copy on his website? Ray?

Or, you could go here: http://www.tmo.com/howto/ecu1g/caps.htm


I'm thinking it's your MPI control relay tho', since you've tapped on it and the truck is running. If your ECU was fried, there would be no running truck <img src="/forums/images/graemlins/cyclops.gif" alt="" />

Eric W.