94 4.0 Start, dies, run with MAF disconnected
#31
Finally found the post & picture by Rockledge, on the super cab wiring harness chaffing problem. https://www.ford-trucks.com/forums/3...und-today.html
Edit: Here is a is a link to the TSB 00-5-4 that Rockledge posted.
https://www.ford-trucks.com/forums/2...ml#post1810777
Edit: Here is a is a link to the TSB 00-5-4 that Rockledge posted.
https://www.ford-trucks.com/forums/2...ml#post1810777
#32
#33
Similar problem...
This thread is the only one that I could find that was close to my problem.
I have a '94 Splash Std Cab w/4.0L Auto
It started having an issue, after a couple of minutes of driving I had less than 5% throttle, with more throttle it will bog more, then full throttle it starts spitting and popping in the intake. I thought I had a vacuum leak, but when i checked with starter fluid, everywhere, there was no sign of any leaks (if you try this be VERY careful!! Do it with the engine cold!! This stuff is extremely flammable!!). The second day this prob started I was halfway to the tire shop to get some new rubber on the new Center Lines I had in the bed, was NOT gonna leave it roadside with $766 worth of NIB wheels in the back! So I limped it down the road, got my wheels on, then when i started it back up it had full throttle! On the way home it started doing it again, bogging at more than 5% throttle and would only do 20-30mph... threw it in neutral and cut the engine, started it back up and it was alive again. I replaced the MAF, then a 2nd one thinking I had a bad part. Looking for other issues I found the leads on one o2 sensor had gotten on the exhaust pipe, charred one of the wires but not burnt through. On the other side the o2 lead had chaffed on the shifter linkage and the black wire was shorting on the linkage. I replaced both o2 sensors but it still has the same problem, after a couple of minutes running it dies off beyond 5% throttle. With the MAF unplugged it will run, with rough idle and sometimes dies at a stop in drive. Up to half throttle it runs rough but will pick up a little, up to 75% throttle, but from there to full throttle it screams...
I'm sure it's an electronic issue, seems with everything plugged in it will run fine until it switches into closed loop. If I assume correctly, with the MAF unplugged it's forcing it to run in open loop? I checked the TPS with a multimeter and the ohms rose steadily and evenly as I opened the throttle...
Someone suggested low fuel pressure, but I can hear the pump build pressure and shut off as normal, also if it was fuel pressure it would be a constant problem right? Not go away if it's restarted...
Scratching my head to bleeding at this point!
I have a '94 Splash Std Cab w/4.0L Auto
It started having an issue, after a couple of minutes of driving I had less than 5% throttle, with more throttle it will bog more, then full throttle it starts spitting and popping in the intake. I thought I had a vacuum leak, but when i checked with starter fluid, everywhere, there was no sign of any leaks (if you try this be VERY careful!! Do it with the engine cold!! This stuff is extremely flammable!!). The second day this prob started I was halfway to the tire shop to get some new rubber on the new Center Lines I had in the bed, was NOT gonna leave it roadside with $766 worth of NIB wheels in the back! So I limped it down the road, got my wheels on, then when i started it back up it had full throttle! On the way home it started doing it again, bogging at more than 5% throttle and would only do 20-30mph... threw it in neutral and cut the engine, started it back up and it was alive again. I replaced the MAF, then a 2nd one thinking I had a bad part. Looking for other issues I found the leads on one o2 sensor had gotten on the exhaust pipe, charred one of the wires but not burnt through. On the other side the o2 lead had chaffed on the shifter linkage and the black wire was shorting on the linkage. I replaced both o2 sensors but it still has the same problem, after a couple of minutes running it dies off beyond 5% throttle. With the MAF unplugged it will run, with rough idle and sometimes dies at a stop in drive. Up to half throttle it runs rough but will pick up a little, up to 75% throttle, but from there to full throttle it screams...
I'm sure it's an electronic issue, seems with everything plugged in it will run fine until it switches into closed loop. If I assume correctly, with the MAF unplugged it's forcing it to run in open loop? I checked the TPS with a multimeter and the ohms rose steadily and evenly as I opened the throttle...
Someone suggested low fuel pressure, but I can hear the pump build pressure and shut off as normal, also if it was fuel pressure it would be a constant problem right? Not go away if it's restarted...
Scratching my head to bleeding at this point!
#34
This thread is the only one that I could find that was close to my problem.
I have a '94 Splash Std Cab w/4.0L Auto
It started having an issue, after a couple of minutes of driving I had less than 5% throttle, with more throttle it will bog more, then full throttle it starts spitting and popping in the intake. I thought I had a vacuum leak, but when i checked with starter fluid, everywhere, there was no sign of any leaks (if you try this be VERY careful!! Do it with the engine cold!! This stuff is extremely flammable!!). The second day this prob started I was halfway to the tire shop to get some new rubber on the new Center Lines I had in the bed, was NOT gonna leave it roadside with $766 worth of NIB wheels in the back! So I limped it down the road, got my wheels on, then when i started it back up it had full throttle! On the way home it started doing it again, bogging at more than 5% throttle and would only do 20-30mph... threw it in neutral and cut the engine, started it back up and it was alive again. I replaced the MAF, then a 2nd one thinking I had a bad part. Looking for other issues I found the leads on one o2 sensor had gotten on the exhaust pipe, charred one of the wires but not burnt through. On the other side the o2 lead had chaffed on the shifter linkage and the black wire was shorting on the linkage. I replaced both o2 sensors but it still has the same problem, after a couple of minutes running it dies off beyond 5% throttle. With the MAF unplugged it will run, with rough idle and sometimes dies at a stop in drive. Up to half throttle it runs rough but will pick up a little, up to 75% throttle, but from there to full throttle it screams...
I'm sure it's an electronic issue, seems with everything plugged in it will run fine until it switches into closed loop. If I assume correctly, with the MAF unplugged it's forcing it to run in open loop? I checked the TPS with a multimeter and the ohms rose steadily and evenly as I opened the throttle...
Someone suggested low fuel pressure, but I can hear the pump build pressure and shut off as normal, also if it was fuel pressure it would be a constant problem right? Not go away if it's restarted...
Scratching my head to bleeding at this point!
I have a '94 Splash Std Cab w/4.0L Auto
It started having an issue, after a couple of minutes of driving I had less than 5% throttle, with more throttle it will bog more, then full throttle it starts spitting and popping in the intake. I thought I had a vacuum leak, but when i checked with starter fluid, everywhere, there was no sign of any leaks (if you try this be VERY careful!! Do it with the engine cold!! This stuff is extremely flammable!!). The second day this prob started I was halfway to the tire shop to get some new rubber on the new Center Lines I had in the bed, was NOT gonna leave it roadside with $766 worth of NIB wheels in the back! So I limped it down the road, got my wheels on, then when i started it back up it had full throttle! On the way home it started doing it again, bogging at more than 5% throttle and would only do 20-30mph... threw it in neutral and cut the engine, started it back up and it was alive again. I replaced the MAF, then a 2nd one thinking I had a bad part. Looking for other issues I found the leads on one o2 sensor had gotten on the exhaust pipe, charred one of the wires but not burnt through. On the other side the o2 lead had chaffed on the shifter linkage and the black wire was shorting on the linkage. I replaced both o2 sensors but it still has the same problem, after a couple of minutes running it dies off beyond 5% throttle. With the MAF unplugged it will run, with rough idle and sometimes dies at a stop in drive. Up to half throttle it runs rough but will pick up a little, up to 75% throttle, but from there to full throttle it screams...
I'm sure it's an electronic issue, seems with everything plugged in it will run fine until it switches into closed loop. If I assume correctly, with the MAF unplugged it's forcing it to run in open loop? I checked the TPS with a multimeter and the ohms rose steadily and evenly as I opened the throttle...
Someone suggested low fuel pressure, but I can hear the pump build pressure and shut off as normal, also if it was fuel pressure it would be a constant problem right? Not go away if it's restarted...
Scratching my head to bleeding at this point!
Have same problem exactly on my 2004 ranger 4.0L XLT 4x4 SOHC . I am going crazy replacing everything and still it only runs right with the MAFsensor off . Replaced it 3 times to mak3 sure it was good. Replaced plugs wires vacuum lines, intake manifold gasket, EGR valve cleaned and new gasket, replaced entire Thermostat housing and new heater valve control, then fuel filter, cleaned fuel injectors and replaced one.Fuel pressure is it 40 with Key on and at 65 when running and holds pressure after turned off . Replaced all o-rings a couple times on injectors when taking them in and out while fixing And replacing other parts. And of course did all the tests and voltage tests on EGR solenoid, purge valve solenoid, tested IAC, Throttle control . It’s like the problem is I can’t get the computer to relearn the fuel trims and air intake percentages since codes where cleared . 0xygen sensors seem to be working right according to diagnostic reader .how did your truck turn out ??please any feedback would be extremely appreciated. Thank you very much
#35
Have same problem exactly on my 2004 ranger 4.0L XLT 4x4 SOHC . I am going crazy replacing everything and still it only runs right with the MAFsensor off . Replaced it 3 times to mak3 sure it was good. Replaced plugs wires vacuum lines, intake manifold gasket, EGR valve cleaned and new gasket, replaced entire Thermostat housing and new heater valve control, then fuel filter, cleaned fuel injectors and replaced one.Fuel pressure is it 40 with Key on and at 65 when running and holds pressure after turned off . Replaced all o-rings a couple times on injectors when taking them in and out while fixing And replacing other parts. And of course did all the tests and voltage tests on EGR solenoid, purge valve solenoid, tested IAC, Throttle control . It’s like the problem is I can’t get the computer to relearn the fuel trims and air intake percentages since codes where cleared . 0xygen sensors seem to be working right according to diagnostic reader .how did your truck turn out ??please any feedback would be extremely appreciated. Thank you very much
Scan the vehicle computer for trouble code clues & post All code Numbers, as they can help focus a trouble shoot.
#36
Caribbeandan35,
I still haven't figured it out, the truck's been sitting with a blown head gasket, damn thing was full of stopleak, had to flush it like 10 times.
I talked to the head mechanic at the dealership, when I was dropping off my mom's Expedition, he said it could be too much back pressure and for like $10 a muffler shop can measure it. He said usually if the computer has problems it won't run, but I wonder if it could be part of the computer corrupted. With the MAF sensor unplugged it forces it to run in Open Loop. But with it plugged in and running, as soon as it switches to Closed Loop it falls on its face like it has a bad vacuum leak. I pressurised the intake with an air line and sprayed soap bubbles, found a few minor leaks and got them plugged up, and no change. I have a new CTS that I haven't put in yet, and haven't replaced the CPS, but I replaced both o2 sensors and the MAF, also the TPS.
Let me know what you figure out with it!
I still haven't figured it out, the truck's been sitting with a blown head gasket, damn thing was full of stopleak, had to flush it like 10 times.
I talked to the head mechanic at the dealership, when I was dropping off my mom's Expedition, he said it could be too much back pressure and for like $10 a muffler shop can measure it. He said usually if the computer has problems it won't run, but I wonder if it could be part of the computer corrupted. With the MAF sensor unplugged it forces it to run in Open Loop. But with it plugged in and running, as soon as it switches to Closed Loop it falls on its face like it has a bad vacuum leak. I pressurised the intake with an air line and sprayed soap bubbles, found a few minor leaks and got them plugged up, and no change. I have a new CTS that I haven't put in yet, and haven't replaced the CPS, but I replaced both o2 sensors and the MAF, also the TPS.
Let me know what you figure out with it!
#37
Have same problem exactly on my 2004 ranger 4.0L XLT 4x4 SOHC . I am going crazy replacing everything and still it only runs right with the MAFsensor off . Replaced it 3 times to mak3 sure it was good. Replaced plugs wires vacuum lines, intake manifold gasket, EGR valve cleaned and new gasket, replaced entire Thermostat housing and new heater valve control, then fuel filter, cleaned fuel injectors and replaced one.Fuel pressure is it 40 with Key on and at 65 when running and holds pressure after turned off . Replaced all o-rings a couple times on injectors when taking them in and out while fixing And replacing other parts. And of course did all the tests and voltage tests on EGR solenoid, purge valve solenoid, tested IAC, Throttle control . It’s like the problem is I can’t get the computer to relearn the fuel trims and air intake percentages since codes where cleared . 0xygen sensors seem to be working right according to diagnostic reader .how did your truck turn out ??please any feedback would be extremely appreciated. Thank you very much
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