1990 5.8 E4OD 140K miles Recently I started to have an issue with longer cranking times to start the motor. This happened shortly afer I put some fuel system cleaner into a full tank of gas (which is nothing new, I use a cleaner about every three tanks). But ever since then the truck has to crank over for a while before starting. HOWEVER if I turn the key to the run position 2 or 3 times before starting - to run the fuel pump - then it cranks right up. So it seems to be a fuel problem that was somehow caused by the fuel system cleaner.

Upon a couple of recommendations here I replaced the fuel filter, although it was new and had less than 1,000 miles on it. That did not fix it. I then replaced the fuel pressure regulator. What a total PITA. It's only three bolts but the location of it and the way that the bolts are makes it much more of a hassle then it needs to be. And that did not correct the issue either (it sure smoothed out the truck though. This truck has always had a very smooth idle but it got even smoother after replacing the FPR. I didn't think that it could get much smoother than it was, but now I could probably balance a coin on top of the intake with the motor running and not have it fall and inside the truck you can hardly tell that the motor is even running). Which is all very nice but it still has the cranking issue and it still starts right up if I run the pump a couple of times before tirning the key.

I suppose that it's down to the pump itself now. That blows. I am -not- dropping my gas tank! This is one job that I'll gladly pay the shop to do. I should check the fuel pressure first, I know. But yesterday, before I removed the fuel filter, I pressed the Schrader valve on the fuel rail to let the pressure out and no gas came out of it. I think that that is a sign of something, right? Fuel filter dying perhaps? Any ideas before I take it to the shop?

 

No pressure at the schrader valve? How long after the truck had been running? Even after several hours there should be at least some residual pressure. Certainly the filter could be the culprit.

A test that requires a cold truck and some careful preparations could help determine if the problem was at or in front of the filter. Basically disconnect the line to the engine from the front side of the filter and attach a length of rubber fuel hose to the open end of the fuel filter. Run the hose into a clear container and turn the key "on". Make note of the volume of fuel in the container after the pump stops. Turn the key off and repeat the procedure with the line from the tank to the filter disconected at the back of the filter. Attach the rubber hose to the open end of the line from the tank. Again turn the key "on" and note the amount of fuel accumulated in the container. If there is a significant discrepancy between the two tests, the filter is to blame. If not, there is a filter "sock" over the pick-up assembly on the in-tank pump that could be clogged but this would require dropping the tank etc.

 

"No pressure at the schrader valve? How long after the truck had been running?"

That was cold, after the truck had sat overnight. At least twelve hours but probably more.

 

PS - I doubt that it's the filter. It did the same thing with two different filters. I put a brand new filter in yesterday and it still did it. It might be the in-tank filter, although I've run enough cleaner in the system since this started to clean twenty tanks. I was hoping that it would work itself out but it did not seem to. I guess that would be too easy.