Ford Repair Questions? Ask a Mechanic for Answers ASAP
Hello, I am John, a Ford dealer technician.
I hope I can help solve your problem quickly and accurately.
This truck is in one of the transition years of carb or fuel injection. Do you know which it is? Let me know and I'll do my best to help you.
it is an efi
Ok, with the key on and engine off I want you to see if you have power at your iac valve. This is on top of the intake right behind the throttle body. The easiest way to check this is with a test light. Let me know what you find.
It should have 12 volts. If you are unsure of what the iac valve looks like here is a pic.
If this is the part and you still do not have 12 volts you will first need to check your battery to see if it is low. If so charge or replace it. If not chances are you have a bad eec power relay. This should be on the drivers side fender or firewall and is brown in color. If you think this could be bad replace it. If this is not the case let me know and we'll go from there.
If you have any more questions please feel free to ask, it's what I'm here for!
important to me so please leave accurate feedback for others to see my job performance.
Yes no problem. I will be at work but I keep up on the website also. It may take at the most an hour for me to get back to you but I will.
i have 12 volts to that part
Does your truck have a check engine light? I'm sorry but this truck is an early model efi truck and all the things we have now weren't standard then. This is why I'm asking all these questions.
Ok this shows that your pcm is powering up and priming your fuel pump. The next check has to be done with a test light. Take the connector loose for the ignition coil. The wire plug not the spark plug wire. Now with the key on and engine off connect the clip to ground and see if the red/green wire has power. After that connect the clip to the positive side of the battery. Now check if the other wire flashes the test light when you crank the engine.
Let me know the results.
Ok, a few more checks and I think we will have the problem narrowed down. Now I need you to pull one of the fuel injector connectors and check it the same way you checked the coil. Look for power on one side and look for ground pulse on the other side. If this is ok I want you to test for spark at one of the spark plugs. Remove the plug and insert into the wire. Lay the plug on the block somewhere so it will get a ground and check if you have spark while cranking. If this is ok then you have spark and injector pulse. The only other options will be if you have a good fuel supply and good compression. Try fuel supply first. You will need a fuel pressure guage to check this. You should have a minimum of 30 psi. If this is low you will need to look at a possible bad fuel pump or restricted filter... or no gas in the tank. If this is ok do a compression test. You should have at least 100 psi on all cylinders with a good battery and the gas pedal at wide open. If low it is possible you have bad timing gears. To verify this get the number one cylinder on top dead center. Remove the cap and see if it points at the number one terminal on the cap, if not rotate the engine one full turn and put it on tdc again. If it still does not line up with number one then you have bad timing gears.
We are just looking for a minimum. I believe these engines run 50 psi. All you need for a basic start is 30. We are just making sure it is pumping.
You can reach me by posting right here.
okay thank you i will get back with you tomorrow evening when i get the tester to check it.