I bought an 89' F150 yesterday. It is a 6 cylinder with the 5 speed and a 4 wheel drive. I bought as a non running vehicle. The previous owner said that he thought the truck had a bad fuel pump.

Today I checked pressure at the rail and sure enough it was 0 psi. Flipping the key and cycling the pump would over 10 times built the pressure up to 20 psi. This afternoon I changed out the pump and filter and now I have 55 psi.

The truck still behaves as though it did yesterday. The engine will start if you pump the accelerator while cranking the engine (about 50% of the time.) In order to keep the engine running you have to pump the throttle continuously, and even then the engine will barely run.

I have a set of noid lights, but it is very hard to get to the injectors and their wiring. I can keep the engine running by feeding it starting fluid and then it runs smooth.

Does anyone have suggestions for troubleshooting the EEC? I have bypassed the EEC relay and the engine will run the same, and it will not run at all without the relay. Therefore I would assume it works properly. I've cleaned the ground on the EEC harness.

BTW two pictures of my $500 toy!

 

First thing you need to do is run the self-test KOEO electrical test to see if the wiring is OK and the sensors have continuity and are reporting the right test voltages back to the EEC Computer.

If you get a 11 or 111 for the KOEO and a 11 or 111 for the stored codes in the CM (Computer Memory) then you need to run the KOER solenoid test to check all the solenoids to see if they are working.

If you do not know how to run these tests go to this link:
Fuel Injection Technical Library » How To Run a Self-Test

Then report the codes back here and we will try to help you.

/

 

You can also get a scan tool for $20-30 and makes testing easier. You did good for $500.

Was the pump you replaced in the tank or on the frame? Was it an in-line fuel filter? There are two types of fuel systems you could have on that truck. The older style has a low-pressure in-tank pump with a high-pressure pump on the frame and the newer has only one pump in the tank. If you have the newer single-pump system then we can look elsewhere if you're getting 55psi however if you have the older setup and replaced the pump on the frame then it might be able to make 55PSI for a short time but might not be able to maintain it if the kicker-pump isn't doing it's job. The older setup was supposed to be discontinued in '87 but was used on some trucks through '90 or '91. I'm guessing if you had the older system you would have had some issues at the parts store like I did with my '89 a long time ago unless you just gave them part numbers instead of having them look up the truck by year.

 

He has a 1989 so he would have the pump on the frame and a boost pump in each tank.
He has 55psi fuel pressure so we need to look some place else for his problem.

Yes the Equus 3145 is a good tester for his system at about $30.00 that he can get at most auto part stores or at Amazon.com. Image below.




/

 

Actually in '88 they switched to the new system but didn't phase out the old so you'll see trucks with both. I had an '89 with he older setup while my dad had an '88 with the newer.

I got my 3145 tester off amazon for less than $25 and I think it was free shipping on orders over $25. Totally worth it IMO.

 

Ford manuals all say the old setup as you call it was used on the F-series until 1990.
It was used on the E-series until 1992.
The 1990 on F-series and the 1992 on E-series has the new as you call it system.
If your father had the new system on an 88 F-series than some one put it on, not Ford.

The old system:


The new system:


/

 

Well I don't know. It would seem I have been given wrong information. A guy at a ford parts counter gave me the line about '87-~'90 being made with both.

 

The new system does not appear in either the 1988 or 1989 Ford F-series shop manuals.
If Ford put it in them then it would be in their own shop manuals.
Not sure but I think maybe some Ford cars had them in 87 on.
Maybe that was what he was thinking about.
I have no manuals on Ford cars after 1971.

 

Maybe. One thing that threw me and the parts counter guys was I could not find and in-line filter on my '89 anywhere. I checked several times and my friend checked and the only filter we found for the fuel was in the reservoir for the mechanical selector. One guy looked at me like I was crazy when I told him about it (why I didn't think to bring it or get a part number I don't know) and another cross-checked until he found one and told me next time to ask for one for an '87 pickup (that might have been the second time I replaced it) and then there was the guy working the parts counter at the ford dealer. My dad's '88 I may be totally wrong about. He had that thing about a decade ago.

 

A Ford F-series gas truck takes the same fuel filter 1987-1995+. Filter number would be FG872.
1985-1986 had the filter in the reservoir.

 

Okay, I did the scan and got codes 22, 32, and 67.

Key on engine off
22 MAP/BP sensor out of self test range
32 EVP circuit below minimum voltage of 0.24 volts
67Neutral safety circuit failure

 

Resolved, maybe?

I unplugged the MAP sensor and the engine took off immediately.

 

That is a good sign. More than once I have seen a bad MAP sensor cause a no start or poor running condition.

 

The 67 is because you did not have the clutch pushed to the floor during the test.

Service Code 32 in Key On Engine Off and Key On Engine Running indicates that the EGR valve and/or EVP sensor voltage is lower than normal in the closed position. The EVP voltage is less than the closed limit voltage of 0.24 volts. Because of the preload of the EVP sensor it is very difficult to determine whether the EGR valve has malfunctioned or the EVP sensor has an abnormally high resistance.

Possible causes:
-- Poor continuity in EVP sensor harness or connectors.
-- Damaged EGR valve.
-- Damaged EVP sensor.
-- Damaged processor.

More than likely the bad wiring or plugs.

 

Truck ran great with little to no hiccups.

Does the sensor short?