ford ignition problem 351

[kmarine]

I have a 1996 ford 351 EFI boss gt 40 engine PCM that falls on its face when it reaches 2600 rpm and surges to about 2200 rpm I have replaced distributor pick up coil and ignition module cap wires and it still surges. there are no codes stored in the computer.

 

[Bondo]

Ayuh,.... Sounds like Water in the fuel,....

 

[kmarine]

I have already checked fuel pump cell for water and ran a fuel pressure gauge to fuel rails. I replaced the long block a month ago. does anybody at PCM return phone calls. I have had a ford mechanic who has worked on these for ford helping me and we cant seem to figure out the puzzle. we have also checked the voltage input and output at all of the ignition components.

 

[Walt T]

I tend to agree with Mr.Bond that it is a fuel problem. I would suggest fuel pressure readings out on the water, and also a timing light hooked up to see if your spark starts dancing around. Verify and verify again the timing marks on the balancer are actually what the timing is supposed to be. I've seen balancers spun and balancers different from one engine to another. Reverify another three times the firing order and verify that you have the correct one. There are two different firing orders for these weird Fords.

 

[jim@silverspray]

Check the low oil pressure switch and the over heat switch it sounds like a possible limp mode or S.L.O.W. mode issue.

 

[kmarine]

yes, It was the wire for the oil pressure switch grounding out against the engine block. the engine went into the slow mode. I do not know why it did not show a code in the computer. Everything now runs great. thanks for your help it is difficult to find people who understand the early EFI ford engines includingsome of the the techs at PCM marine engines..