So from time to time, this truck will turn over and over, but wont start. You give up, leave cussing, go drink some coffee, and come back, it cranks. Ive heard anything from dist, cap, fuel filter, starter.

Now im starting to think fuel filter because 2 of those times it just stopped AFTER it had been idling for a while. I dunno.

Any ideas???????????

 

I'm assuming your '86 is carb.

Check your spark. Spark testers are cheap and readily available and usually do 4 cylinders at once, or just connect a plug and lay it against the block, one at a time. Have an assistant watch it for sparks as you crank, or use a remote start button if you have one. If the sparks are intermittent or weak then there's likely a dist. problem. If the sparks always look good but it won't start, then you have fuel issues.

One of the times it cranks but won't start, dump a bit of fuel down the carb and try again. Start then die? Not getting fuel, or not enough, so the fuel filter would be a good place to start.

When it does run, does it run well? Can you go WOT for more than a few seconds? Does it want to bog down on heavy load or high RPM? If so, there's a good chance it's fuel filter. If it runs fine, my next guess would be a bad check valve allowing all the fuel to drain back to the tank when stopped, though it should still start off the fuel in the bowl. I really don't know much about large engine carbs. I think you need a special tool to remove the fuel filter on these, there's two tabs inside the hose. They're like $2 at auto stores.

If your spark is crappy, inspect the cap rotor. Cracked towers? Corrosion on the button or contact faces? If in doubt, replace. They're not expensive.

Starter? Unless it cranks really slow ("loping") that has nothing to do with your issue. If the motor spins, it's doing it's job.

 

I'm assuming your '86 is FI.

You need find out first if you have spark, use a spark tester.

If you have spark then you need to put a fuel pressure gauge on the fuel rail.
Ground pin #6 of the test (VIP or DLC) connector with the key on and see what fuel pressure you have. You should have about 43 PSIG.

If you do not have the fuel pressure then it could be a filter but more than likely you have a bad in tank fuel pump.

The spark tester and fuel pressure do not cost too much and are a lot cheaper than just replacing parts without fixing it.

Let us know what you find.

 

Hi there, Yes it is FI. It runs very good. Its never cut off while on the road. Just idling, and once just as i was releasing the clutch to go. Thanks for the ideas. And guess what, it just cranked again, about an hour after it wouldn't.

 

If you do not have spark when it does not start I would change the TFI module on the side of the distributor first and if it does it again I would change the PIP sensor inside the distributor. Most just change the distributor when it is a bad PIP sensor.

 

Next week its scheduled in the shop to get the distributor, and plug wires/plugs replaced. So I guess doing that would take care of both of those things, right? My mechanical knowledge is limited so bare with me

 

Yes most distributors come with aa TFI module on them and of course they have a new PIP sensor inside.

One other thing you might do is see if you have any codes stored in the computer.

To check your codes go to one of these links below:

This is good for the KOEO test:
http://fordfuelinjection.com/?p=13

This one is good for the KOER test:
http://fordfuelinjection.com/?p=94
OR
http://www.broncodata.com/tech/codes.htm

 

Thanks for your help guys, the dist. cap is getting changed out Monday, so I guess we'll see what happens.

 

The "dist. cap" is not going to help get the spark back, I was talking about the whole distributor with the TFI on the side.

 

Im getting the whole thing changed, thats what iI should have said, Thanks!