Loss of power

[kevinplmr]

I have a 1991 explorer 5 speed manual. Lately i have noticed when driving it is having a problem with loss of power at about 3000 rpm, backfires a little when it does this. It is fine in neutral and you take it up over 3000, just when it is under load i have problems. Could this be converter?

 

[MrShorty]

I don't think the "converter" (I assume you mean torque converter) could cause a "backfire" From what little I know of backfires, they are usually either a mixture or a timing issue. My first thought on this is a fuel delivery problem: a case where fuel delivery can keep up with engine demand when there's no load on the engine, but fails to keep up under load. 1st thing I'd probably do in this case would be to put a fuel pressure gauge on it and see what fuel pressure looks like. Maybe even rig ti up so I could monitor fuel pressure while driving to see what it is doing under load.

I'd probably also pull codes from the computer, just because it's easy and only takes a few minutes. Instructions are in any good manual and in the EEC_IV forum here. Note that the CEL doesn't have to be on for the computer to have information in it.

 

[kevinplmr]

Actually i meant cat converter

 

[safn1949]

Could be converter,but I would check fuel pressure,if it leans out it will backfire.Low fuel pressure = possible lean mixture at high rpms.