I have been trying to trouble shoot a starting problem with my ’91 Formula 350. It doesn’t feel like it is getting any fuel at start up. It takes about 7 seconds of cranking, then stop, then start cranking and it will usually fire. In about two days it went from no problem to won’t hardly start. When and if it starts it is very rough for a few seconds, then once it get going it seem to run fine. I replaced the fuel filter and that hasn’t helped. I was looking through the Hayes service manual and they showed a engine electrical schematic that showed a fuel pump relay and a fuel pump/oil pressure sending unit switch. Can someone tell me where to find these? Also it showed an in-line fuse for the pump. Where’s that? The manual also talks about a fuse on the fuse block labeled “FP” to cut power to the fuel pump. I don’t see any fuel labeled “FP” on my fuse block. Is it labeled something else? Another question, in the manual they talk about energizing the “G” terminal on the ALDL (Assembly Line Diagnostic Link) with 12V to will turn the fuel pump on to verify it is working. My “G” terminal (lower right corner of the connector) does not have a pin in it? Is it not there or somewhere else? I know there are a lot of questions. The manual isn’t real clear and I don’t have a lot of experience with these cars. This message board is a real help for people like me. Keep up the great work. Thanks.

-Chris

 

hey dude!

i had the same problem with my 92 RS. it was hard to start and would run real rough and lots of smoke came out the exhaust. it would smooth out after a while. turns out the sensor that connects under the air filter housing (i forget what it's called) wasn't connected. harness was broken. replaced it with one from autozone and it solved the prob.

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"WARNING: Objects in mirror are about to disappear VERY quickly!"

 

That's the MAT sensor. The FP on my fuse block is one of the injector fuses but there's another one by the battery. It should be on the side of the engine bay with a 20 amp fuse in it. If you take that out, the fuel pump won't operate.