BlueBronk

Stock '91 5.0 w/ MAF running in an automatic. New injectors, plugs, and plug wires were installed when this donor motor was put in. Motor was put in a year ago and never have got it dialed in. Starts very quick. Idles pretty good with a very slight miss. Occasionally idles up and down some???? Every once in a while it will die when idling. When driving it for a few minutes it seems to run good. 10 minutes into the drive, and the rest of the day...it runs, but backfires and stumbles. If you step on the gas...it usually goes away until you slow back down to cruising speed and then it will start doing it again. Its a muffled backfire sound maybe through the exhaust..hard to tell. Will definitely do it under load on a hill when not giving it much gas, but if you put it to the floor...it goes away again. I have used gas treatment, ethanol free gas, etc.. Any ideas on these problems? Could this bve timing? Also..what is my timing supposed to be set to?

Thank you,

Andy
BlueBronk

89LX Coupe

I had this same exact issue and mine surged real bad when ever I ran my SD ecu but once I put my maf ecu back in and connected ever thing back up it ran fine and perfect. So I'm interested in seeing what the issue could of been....

4rdnut

timing is 10 degrees, make sure the spout connector did not fall out.

zebo87

when was the last time your maf was cleaned

whiteNblack95

check your timing. i believe the stock timing is 10, it sounds like its either a fuel or timing issue. pull the timing spout out and see if there still is a miss at idle. do you have a fuel pressure gauge?