help! I have 91 3.1 multi port.getting spark to plugs,compression is 160/175 through out. replaced tps,fuel pressure reg,computer,map sensor,ign module,coil,cap.plugs,rotor. I even cut a hole in front of converter.replaced fuel filter. fuel pressure is 43psi and does not drop.I can spray carb cleaner into intake and it trys to fire...spits it back out like a bad intake valve,or timing off.I checked timing at tdc...its fine.I am a mechanic but old school...not into the new stuff.I have obd 2 scanner and it was getting a code for map sensor..but that did no help.I have new spark plugs but they foul right away.I have bead blaster in my shop and cleaned them off and re-installed them...fouled again.I jumped out oil pressure switch also. I thought this car would be an easy fix! was i wrong! any suggestions?....Danny

 

to get mine running, I had to change plugs, distributor cap, fuel pump, filter,alternator,
and Im not sure to the validity of this or not.. But the mechanic said he had to reset the fuel safety switch, when I got it fired up it had an odd idle, it would rev up to about 3500 then down then back up etc until it warmed up, which was the Idle Air Control Valve.
when you do get it running... Pour seafoam into the brake booster line to clean out the internal of the engine

 

Dan, was the vehicle not running and sitting for a long time? Are all the plugs fouling or just certain ones? Is it oil fouled or fuel fouled? It almost sounds like your injectors are stuck open.