Runing rich, better when warm

[shifty01]

hi all, im trying to fix someones 92 laser turbo, it runs vary rich and misses under moderade acceleration. it is horrable when cold but still bad when warm. i checked all the sensors at the ecm harness and they were all good including:

coolant- good, watched change as it warmed up, in specs
o2- good, even at .9v so its telling the ecu its rich
iat
air flow
everything else

the ecu looks like it has been replaced before, we replaced the plugs and wires, used the ngk plugs everyone recommends, gaped at .030

im thinking it might be the fpr causing the rail to have too high of pressure, so i check the solinoid that is inline with the fpr's vac line and found infinate resistance, started it and let it idle, unplugged the vac line to the fpr, felt good vac. so im wondering what that solnoid does, all i can figure is it blocks vacuum when the ecu says so, but in my mind that would make it run lean if it was busted. so anyway i was looking at the fpr, and i know i will need a pressure gauge to test it, but if i rent one from autozone or napa will it have the right fittings? has anyone else had there fpr go bad and stick shut? anyway to clean it?

sorry for the bad spelling

oh yeah, checked the coil packs too, both were in specs and some times, when everything is just right, it will run like a champ, but that only lasts about 3 mins before it starts missing again

 

[shifty01]

ok new info, i thought it might be the air flow sensor so i unplugged it and drove a bit, it idled a little rough but it accelerated great, i dont think it missed once when accelerating, it also cruses rough with it unplugged, the o2 sensor it still on the rich side, but its not nearly as bad as before (not blowing black smoke out the pipes when unplugged). so i searched and saw something on the honeycomb on the maf, so i took it out to look and the honeycomb part is missing on both openings (previous owner). so im wondering how bad that would mess up the sensor, someone must have some info about this.

 

[Talesin]

Assuming it's a stock MAS and not a MAFT with a GM MAS, it'll screw it over pretty damn good. There's a reason the instructions for lower-comb removal state in very large letters that you should avoid damaging the upper honeycomb in the slightest, much less removing it.

Time for a new one, sounds like.