corie5.02007

ok i got a 91 5.0 sd. the car started missing and running rough a few day ago. i thought it could be the engine so i hooked up a vac gauge, and the engine seems to be fine mechanically, but i cant fig. if its spark or fuel, ive had problems with the injectors in the past. but ive got spark, ohmed the coil, its fine. checked cap and rotor, its seems to be fine too. its confusing me, plz help

PRO50SC

Does it miss at idle, running down the road, both/ Need a lil more info.

94StinkinLincoln

fuel problem maby? pump, filter, regulator?

corie5.02007

alittle at idle , more when accelerating

dimebag

does it sound like a miss? or detonation?

and sd.... meaning speed density? why is a 91 a speed density car?

Blckstng93

MAF replaced SD in 88-89. If you got SD it was converted from MAF. Could be a problem if it wasnt done right.

You sure its SD?

corie5.02007

yes it does mean speed density, and no its not that. i did the conversion myself cuz my maf ecu fried. but i just found a new clue, excessive oil in the intake manifold, could that be something?andim pretty sure its amiss, the engine shakes alot when accelerating.

Derf00

Pull your spark plugs, you may have cracked the porcelain or nose cone on one.

corie5.02007

i put all new spark plugs in it, does anyone think the oil has somthing to do with it? i dont think so, cuz it feels like a ignition miss. but it could be.

samseed101

You most likely have oil in the intake because it's getting sucked up by the PCV valve and spit back into the upper. I guess ht could foul your plugs, but you said you changed them. wouldn't hurt to install an oil / air seperator anyway.