Won't run? Why? 1989 F150 4.9 6cyl

sybartic · 11-21-2006, 01:01 PM

1989 F-150 2wd 4.9 Straight 6
Dual Tanks

Bought the truck not running. old owner said that it just stopped cranking. easy enough... it was just the rod that runs from the cylinder to the switch. now it cranks. Apparently from the look of things, someone had done a tune up to it before the rod issue. They "said" it ran before it just stopped cranking for them. I'm inclined to believe that it did run. From the look of things, it looks like a new distributor, cap, rotor. Oxygen sensor has been replaced as well. Wires look older.

Here's what I have done:

New coil. spark is good.

They had put a new ignition module in. I put the original back in because I broke the new one taking it off to make sure everything looked kosher down there. (don't ask) Am I correct that ignition modules either work or they don't? If there is an in between this could be a possibility. It has spark.

New Fuel pressure regulator. Gas was spewing out of the vacuum side. Obviously a big problem. Replaced it. Is there a priming procedure for these EFI trucks? haven't checked fuel pressure, but it spurts on me when i hit the valve on the back of the fuel rail. I can hear fuel pumps running as well. Put fresh gas in it.

New plugs. Cranked it enough to get them covered in fuel. Since replacing the the plugs i have since pulled them back out, wiped them down, and spurted a little oil down in each cylinder and let it sit for an hour.

Changed the oil, just because it was dumping fuel everywhere, and if it did fire i didn't want oil full of fuel in there.

The truck does not pop on ether (starting fluid). I'm used to working on EFI, so maybe this has something to do with it. But i'm not an expert here.

I tried putting a timing light on it to see if they put the distributor in wrong. It's gummed up and have yet to find the mark, so no conclusion there.

Any help would be appreciated. I'm a little clueless here. I have means to check sensors, but i don't know what the resistance is suppposed to be, so it's kind of pointless.

Thanks in advance.

goon · 11-21-2006, 09:29 PM

check the firing order is right and make sure the timing is right.(top dead center and distr. on number one. also i think the fuel pressure for the 6cyl is about 55 psi.