Question about the ECM

bkea · Mar 20th, 2006, 01:15 PM

My truck is still running pretty crappy after the engine rebuild. Runs OK once warm and up to speed. Still acts weird when cold and it town. Idles a2200 rpms when cold. When the fuel pump wouldn't work, the electric shop said the ECM wasn't putting out a ground signal to the fuel pump relay. He wired in a temp ground and said I need a new ECM. I've looked but they are $$$$$.

QUestion is, will the vehicle run at all if the ECM is bad. I tried to pull codes yesterday and it downloads a code as soon as I turn the ECM on then off. It doesn't seem to want to change modes. Seems its always in mode three. BTW it gave me a code 4-4.

dvdswanson · Mar 21st, 2006, 02:44 PM

have you checked junkyards for an ECM?

bkea · Mar 21st, 2006, 05:18 PM

An ECM out of a junkyard is iffy because they are usually "as is", and have no garantee. Also import parts around here are expensive. We have no pick and pull places. Also, the unit is specific to each model, year, engine and trans. The electrical guy that worked on it said he wouldn't try a junk yard unit, but I could try to find one. I have seen a vendor on eBay that was selling some rebuilt units for around $125 plus shipping. Later I saw you could send them your and they repair it and return. I've just gotten a little jumpy about using eBay any more.

dvdswanson · Mar 22nd, 2006, 12:47 PM

I would check with the junkyard, some reputilbe(sp?) ones will have a small warranty like 30 days or 3mos/3k miles, it just depends on the yard. if you have to send it in to somebody I would go with a known performance shop that way you can get a little more power to boot.