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zukirider21
New Member
- Joined
- Jul 23, 2009
- Messages
- 851
- Reaction score
- 5
- Points
- 0
- Location
- NJ
- Vehicle Year
- 89
- Make / Model
- Ford
- Engine Size
- 2.9
- Transmission
- Manual
Alright guys, I'm going to try and make this as complete but painless as possible. My friend recently bought a 94 Ranger XLT 4.0 OHV A4LD 4x4, its in nice shape, virtually zero rust, only 104k on the clock, etc. For the past few months we've been doing all sorts of stuff to it; repairs, mods, and just general maintenance. Overall the truck is in very good standing.
There's just a few issues we cant seem to shake. First- *Only sometimes* when you go to start it (engine hot or cold makes no difference), it'll start, surge between 500-1500 for a a few seconds and shut off. It will only do this 2-3 starts, then it will finally keep running, poorly. It will also nearly die when you go to put it into gear.
Next issue is more often than not, the truck likes to "buck" for the first half mile or so when taking off. It will do this hot or cold, whenever it feels like it. One thing I do know is that this is an engine issue, not driveline. My friend described it to me as almost like when you bog down a manual car too low.
One thing I noticed was even when the truck is in a good mood and running really nice, if you REALLY stab the throttle, full WOT, the engine will usually just fall flat on it's face, break up super bad, and you'll go nowhere.
The last issue is totally random. Sometimes the temp gauge sweeps from full cold to full hot, randomly. This is most definitely an electrical issue, not a problem with the cooling system (I've been through the whole thing).
I would tend to think issues 1,2, and 3 are related, and 4 is not. Even though both temp sensors tested fine, I'm going to get a new one-wire ECT (the one that runs the gauge) just because its so cheap and easy to do. Maybe that will knock #4 off the list, at least. As far as 1,2,3 I was initially thinking vacuum leak, unmetered air, or MAF issue but I wasnt able prove any of that. One thing I have not yet looked into is fuel pressure and I'll have to do that next week. But regardless, I want to hear people's input, maybe someone went through something similar.
I think the easiest thing to do is just to make a big list of everything thats been done to the truck so far. Some things are relevant, some are not. I'm just going to list everything I can recall doing (this truck had other issues that I have diagnosed and fixed, a nasty ping was one of them).
new plugs and wires, coil pack looks recent
engine was de-carboned with motorcraft PM-3 three times as per Ford's tsb
Lucas fuel sys cleaner was run for a few tankfulls
cleaned MAF
repaired ripped intake boot
checked tps voltage for proper idle and WOT range
exhaust has no leaks, new 2.5" catback system with 10 series fartmaster
ohmed out BOTH coolant temp sensors, they seem dead on
searched for intake and vacuum leaks like a madman, to no avail
i dont think it has any codes. no light but i dont have an OBD1 scanner
Not gonna lie guys I'm pretty stumped. ANY input would be greatly appreciated!!
There's just a few issues we cant seem to shake. First- *Only sometimes* when you go to start it (engine hot or cold makes no difference), it'll start, surge between 500-1500 for a a few seconds and shut off. It will only do this 2-3 starts, then it will finally keep running, poorly. It will also nearly die when you go to put it into gear.
Next issue is more often than not, the truck likes to "buck" for the first half mile or so when taking off. It will do this hot or cold, whenever it feels like it. One thing I do know is that this is an engine issue, not driveline. My friend described it to me as almost like when you bog down a manual car too low.
One thing I noticed was even when the truck is in a good mood and running really nice, if you REALLY stab the throttle, full WOT, the engine will usually just fall flat on it's face, break up super bad, and you'll go nowhere.
The last issue is totally random. Sometimes the temp gauge sweeps from full cold to full hot, randomly. This is most definitely an electrical issue, not a problem with the cooling system (I've been through the whole thing).
I would tend to think issues 1,2, and 3 are related, and 4 is not. Even though both temp sensors tested fine, I'm going to get a new one-wire ECT (the one that runs the gauge) just because its so cheap and easy to do. Maybe that will knock #4 off the list, at least. As far as 1,2,3 I was initially thinking vacuum leak, unmetered air, or MAF issue but I wasnt able prove any of that. One thing I have not yet looked into is fuel pressure and I'll have to do that next week. But regardless, I want to hear people's input, maybe someone went through something similar.
I think the easiest thing to do is just to make a big list of everything thats been done to the truck so far. Some things are relevant, some are not. I'm just going to list everything I can recall doing (this truck had other issues that I have diagnosed and fixed, a nasty ping was one of them).
new plugs and wires, coil pack looks recent
engine was de-carboned with motorcraft PM-3 three times as per Ford's tsb
Lucas fuel sys cleaner was run for a few tankfulls
cleaned MAF
repaired ripped intake boot
checked tps voltage for proper idle and WOT range
exhaust has no leaks, new 2.5" catback system with 10 series fartmaster
ohmed out BOTH coolant temp sensors, they seem dead on
searched for intake and vacuum leaks like a madman, to no avail
i dont think it has any codes. no light but i dont have an OBD1 scanner
Not gonna lie guys I'm pretty stumped. ANY input would be greatly appreciated!!
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