I need some help cause I'm running out of money and getting frustrated. I have a 1987 F150 302 EFI. I have replaced both fuel pumps w/ filters, the inline filter, TPS, EGR valve w/sensor, new plugs and wires, seafoam gas treatment, flushed the transmission and replace the transx filter, replaced the Speed sensor, new Cat-converter and muffler. I've also cleaned out the IAC.

The truck starts fine, Idles ok..in a loop by stays running. The engine revs up fine in park. When in drive and I accelerate there is no power. The engine sputters and bucks along when I give it some gas. I can make it through the gears but I have to constantly feather the throttle. If I do attempt to aggressively accelerate the engine bogs out and sounds like it may be back firing into the manifold (I think, not to sure). I have been reading a lot of other posts and some say TPS, others say Distributor. I have an OBD1 but I get no relevant code. I also am not sure I know how to run all of the test. When I do a KOER I get 12,13, That's The IAR I believe, 44,34 77. When I do a KOEO I only get a 34. The 34 seems to have something to do with EVAP/EGR system. I needs some help

Thanks

 

Id check if your getting good spark. I have my tps unplugged and dont have problems with it. Could getting too much gas?

 

Ok, as you suggested I went and change out the distributor cap w/ rotor, plugs and wires. The spark is all new. The problem stills persists but in slightly better than before.

thanks

 

check your fuel pressure.. i'm betting your highflow pump on the frame rail is weak. and wont build up pressure fast enough when the motor is under a load.

 

How can I check the high flow pump?

 

You check for fuel pressure on the fuel rail with a pressure gauge, when they start to get weak they start wining and the engine will bog down.

 

Ok folks I have an update. I should tell you that the gas tanks on this truck were rusty beyond measure. I cleaned them months ago and changed the in line filter twice. Having said that I never considered the inline filter to be the problem, well it was. I took it off and then cleaned it out just to test it. Large chunks rust came out of the filter as i pumped it in revers with and air tool. I put it back on and all the power returned. Thanks to all that responded