silly rednecks

[hkerekes]

I bought an 89 2wd extended cab for cheap. The previous owner ( redneck ) "fixed" alot of issues that I knew I would had to correct.

One is the fuel pump wiring. He has hotwired the fuel pump from the fuse box.

The factory wiring at the pump only has 6 ish volts. I tried looking for the inertia switch and I think it is gone and he just connected the wires. There is an orange / black stripe and a pink / black stripe connected in the footwell. I guess that would be the inertia switch wires.


The fuel circuit goes from the ecu - relay - inertia - fuel pump correct?

The truck doesnt run smooth and really bogs down when it gets hot. I think the fuel pump is overheating and causing issues.

I guess I need to find the inertia switch or lack of and test for 12v there. Then once i figure that out i can trace the wires to the pump and find out why the voltage is low on the factory wires.


There is no inertia switch and the local parts stores dont carry one. Where other than the dealer and ebay do people get them?

http://cgi.ebay.com/ebaymotors/FORD...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories That should work correct?

 

[Earl43P]

http://www.therangerstation.com/tec...es/Diagrams_ElectronciEngControls2_9_1of3.JPG

I'd figure out the real problem, THEN worry about the missing inertia switch. Perhaps the fuel pump relay itself is bad. That splice would be a handy place to take a voltage reading. If it's low there, suspect the relay. I would suggest cleaning up ALL the grounds on the truck, particularly those in the engine bay (little ones on the fenders, radiator support, windshield wiper motor nut, etc.) Low voltage could easily be a bad ground.

 

[Boggin]

if you want a switch, PM me i got a couple

 

[hkerekes]

http://www.therangerstation.com/tec...es/Diagrams_ElectronciEngControls2_9_1of3.JPG

I'd figure out the real problem, THEN worry about the missing inertia switch. Perhaps the fuel pump relay itself is bad. That splice would be a handy place to take a voltage reading. If it's low there, suspect the relay. I would suggest cleaning up ALL the grounds on the truck, particularly those in the engine bay (little ones on the fenders, radiator support, windshield wiper motor nut, etc.) Low voltage could easily be a bad ground.

The grounds on the engine bay are all moved around. I see a new one on the intake to the rad support and I think one on the fender going somewhere in the harness but thats it IIRC. Would 2 coming off the intake to the chassis be sufficient?

Other sensors have good voltage, I checked the TPS and it was fine. I bet the relay is shot and he didnt know where it was. It idles kinda ruff and top end power is lacking, sometimes when it gets hot enough it really loses power. It has a recent tuneup, new 02 sensor which helped, new coil which helped a bunch. The firing order is correct and the cats arent clogged because he removed them.

if you want a switch, PM me i got a couple

I bought that one on ebay for $30. Oh well, thanks tho.

 

[Boggin]

ok cool.. good luck man

 

[hkerekes]

I have 12v at the inertia switch wires.

I found the relay with the green bottom under the fuse box in the engine bay. The wires had 12v / 12v / 6v and no voltage. They didnt seem to change whether I had the relay connected or not. If there is 12v at the inertia then it has to come from the relay correct?

 

[BRUTUS_T_HOG]

your relay wires should have 2 powers 1 ground, and 1 that goes to the fuel pump.

the fact that you have 6v on one of the wires tells me you might have a bad ground circuit to the PCM, but i don't know what wires you're testing, only that its not right

 

[hkerekes]

your relay wires should have 2 powers 1 ground, and 1 that goes to the fuel pump.

the fact that you have 6v on one of the wires tells me you might have a bad ground circuit to the PCM, but i don't know what wires you're testing, only that its not right

I put in a new relay and fixed the ground from the intake to the rad support, the harnes ground to the fender and the ground on the wiper motor.

It gets 12v in and 12v out on 2 wires. Then it will change 12v to 6v on one of the wires but it wouldnt ever get 12v before.

The pump runs off of the factory wiring now so that relay was bad. I have the inertia switch coming.

Where is the ecu ground? It still will run fine and when it heats up sometimes it will lose alot of power. The tps is fine, the engine coolant sensor is new, the 0xygen sensor is new, the coil is new. Each one of those made it run better but it still runs crappy.

 

[BRUTUS_T_HOG]

have you checked fuel pressure when it loses power?

 

[hkerekes]

have you checked fuel pressure when it loses power?

not yet, i need to grab a cheap gauge somewhere. I believe the pump is fairly new but it was hotwired so it might be shot i dunno.

I'm slowly fixing / replacing parts. It still taps all the time. The rocker shafts are clean and the oil is clean. It had a bit of sludge and buildup on the valve covers and top of the head. I have done 2 oil changes with a little bit of seafoam and it cleaned up the sludge but the tap is still there. Sometimes it changes pitch and frequency a little so i'm hopeful. heh

 

[jhammel85]

The bogging sounds alot like a problem with the oxy sensor or with its wiring. Make sure the wirings good.

Gotta love red neck wiring right? I had the same crap with my truck.....

 

[hkerekes]

The bogging sounds alot like a problem with the oxy sensor or with its wiring. Make sure the wirings good.

Gotta love red neck wiring right? I had the same crap with my truck.....

I suspected the oxygen sensor and it looked origional. I replaced it and it didnt seem to change much.

I just checked the fuel pressure. It ran fine home today and didnt really miss / stutter when it warmed up. KOEO has 32 pounds. KOER has about the same, give it some throttle it jumps to 37 and back to 32. However I could not get it to miss/stutter on me.

It seemed to run better today but still doesnt seem eager to rev. It definetly runs better when the engine is cold. I just cleaned the 2 grounds near the ecu, they werent corroded but i figured why not.

 

[jhammel85]

When the truck is cold, Its in a open loop.
Basically its "ignoring" fuel trimming sensors like the oxy sensor. Hows the wiring on the oxy sensor?

Heres some more info on open loop and engine load...
http://www.fordfuelinjection.com/?p=4

More good info.. The next site has a table with what sensor is running when. Might help you track something down..

http://www.fordfuelinjection.com/?p=3

http://www.fordfuelinjection.com/?p=95

Are you getting any codes at all??

 

[hkerekes]

When the truck is cold, Its in a open loop.
Basically its "ignoring" fuel trimming sensors like the oxy sensor. Hows the wiring on the oxy sensor?

Heres some more info on open loop and engine load...
http://www.fordfuelinjection.com/?p=4

More good info.. The next site has a table with what sensor is running when. Might help you track something down..

http://www.fordfuelinjection.com/?p=3

http://www.fordfuelinjection.com/?p=95

Are you getting any codes at all??

The oxygen sensor is new and the wiring is factory and looked good. I will look at teh links you posted. I have a decent knowledge of cars/computers.

Sometimes I can drive it for 40 minutes and its fine. Other times after 20 minutes it loses power. Usually only when it is at operating temperature. Today the whole ride home is was fine. ( 40 minute ride ). I figured the oxygen sensor was shot so i replaced it. Every thing i replace helps but doesnt fix the problem, just makes it slightly worse.

Oxygen sensor, coil, plugs,wires,cap,rotor,fuel filter, engine coolant sensor, are all new. The tps checks out ok. Fuel pressure is fine but not sure about when it misses / stumbles. IAT unplugged makes it worse so i doubt thats the problem, Vacuum is 20psi at idle and i havent found any leaks. PCV seems to be functioning.

Does the 89 v6 have a knock sensor?
I guess since the thing taps it may be picking up on the knock when it warms up? I might go ahead and replace the air temp sensor, for 17.99 its one more thing to rule out.

 

[hkerekes]

This morning it ran great at first then back to rough when it warmed up. All I did last night was clean the grounds on the ecu. I pulled the codes when i got to work to see if there were any. Code 54 came up, ACT too high. I had suspected the ACT sensor so I replaced it. It seemed to run even better. After work I had to drive an hour and then an hour and a half home.

The truck ran great for 45 minutes and then started to run a little rough but not bad. During the ride somehow the powersteering pump puked a bunch of fluid all over the fender well / coil I have no clue how or why but it was everywhere.

On the trip back home It gave me a check engine light and it really went to shit. I had to floor it in 4th to keep 55mph on the highway. It was missing really really bad. I pulled over and code 54 was back. It had never run that rough before. Why would a new sensor run great and then all of a sudden turn to garbage?

I am going to check the sensor tomorrow. Hopefully It is faulty and I can have it replaced. If it checks out ok then the wiring is shot or the ecu is faulty.

Any other ideas?