Welcome Visitor! Please take a few seconds and sirhk100
Member
- Joined
- Apr 29, 2013
- Messages
- 5
- Vehicle Year
- 1991
- Transmission
- Manual
Okay, 2nd post on this forum and a copy of one I did in the general section. I didn't realize there was a specific area. I didn't scroll down far enough. My bad... I got to the off topic and classified stuff and just figured there wouldn't be tech stuff below it. Whoops!!! So I'm pasting this here...
'91 Explorer, 5 speed manual. 4.0L 4WD.
I've just finished a fairly extensive build on a custom suspension system and took it out for a road test yesterday. Everything related to the suspension/chassis worked amazing!
That said though... Cause of some modifications I've made to the engine compartment and shock mounting setup, I was left with only 1 option of mounting the air filter and that was on the drivers side between the radiator and the coolant overflow/window fluid tank. Now I was a bit skeptical about doing this worried that extending the harness may mess up the resistance in the harness cause I know some older vehicles engineered the harnesses this way but I went for it anyways. I added about a total of 12-15" of harness length to the MAF sensor. I soldered the harness, no goofy butt connectors or anything like that.
Now I finally got the truck ready for it's test drive. It was about 95-99 degrees here in Vegas yesterday. I first took it for a spin around the neighborhood. I've got an ENTIRE new front suspension system with a lot of custom work done. I was checkin for handling, brakes, clunks and noises, etc... I did NOTHING to the engine though other then unplugging and plugging back in a few harnesses and the MAF harness extension. It ran fine. So pulled it back in the drive, made a few suspension tweaks, double checked a few things and went for a road test to run an errand actually. Left the house, Did about 10 miles of city street driving. Stop lights, a little traffic down near the strip, etc... Everything great!!!
Ran into a store for about 30 minutes, came back out, fires up great. Take the long way home and hop on the freeway. Cruising along at about 70mph for about 10 or so miles. It's well past just being warmed up at this point and scooting along fine, like I said, we pushed 100 degrees today.
All of a sudden I'm loosing power... It doesn't just die instantly but I can tell it's sputtering and going down. I get off to the median and make a choice to coast it to the next offramp with the momentum I have. Get well off the freeway and figure it's gotta be wiring related cause I didn't do anything else. I check a couple plugs, nothing... Well, actually at this point, what it's doing is it'll start and idle but any throttle and it just about stalls, pops, sputters, backfires thru the intake, etc... After a bunch of wiggling it fires up though, I toss on my seat belt and pin it heading home using back city streets. It basically ends up to the point where it'll run normal for about 45-60 seconds, then falls on it's face. I coast to a stop, turn it off, wiggle wires, back in and go for another round. Takes me about 6-7 rounds of this to get to my driveway. Now I have to say, I'm not 100% sure wiggling the wires was doing anything. It was just a routine that was getting me closer to the comfort of my driveway so I did what worked, I could've possibly just turned it off for a minute and fired it back up and had the same results. At that point though, I just wanted back to my driveway.
In my driveway I look at the plugs I'd messed with during my suspension build. I find one with only 2 wires on it and they're both bare for about 3/8" right as they go into the plug!!! BINGO!!!! I can deal with this... Insulate them and figure game on! It fires right up in the drive so I decided to run to the store with it.
I make it about 1/2 mile and it's doing it again. CRAP!!! I jump thru the routine of wiggling wires still thinking it's gotta be related to that. I get back home.
I plug in a fairly decent OBD1 scanner I have. For some reason I've never been able to connect to do a engine running scan for as long as I've owned it but I've been able to do key on engine off scans.
The only code I pull is a 66. MAF voltage too low.
CRAP!!!! Is this due to my extended harness?
My hesitation with assuming that is why was I able to drive it for probably 20 minutes on the city streets problem free, then another 10-15 minutes on the highway problem free before it gave up? I'd have thought if it was related to my harness it would've been doing it from the get go, not 30-45 minutes into a test drive?
Thoughts? The expo has been sitting for about the last 6 weeks during my build. I have started it for a couple minutes probably about 3 times during that duration but didn't drive it at all, just let it idle up to temp and that's about it.
I've got another expo to rob parts from... I actually was going to pull that plug with the bare wire and splice it in as a replacement but the one on my other expo isn't using the same pins. My problem expo has only 2 of the 8 possible pins in use where my other is using like 6 of them. The other one is an auto trans though so I'm guessing that's the difference.
So, Code 66, MAF voltage below minimum, is it cause I extended my harness? If so, why did it take 30-45 minutes to start acting up? If it was a warm up issue I know darn well it was at full operating temps WELL before then.
The little reading I've done online this morning seems to be that a lot of the times code 66 is a vacuum related issue. Doesn't really make sense considering the code detail but then again, this isn't cutting edge technology either.
Any ideas?
Thanks,
Khris
'91 Explorer, 5 speed manual. 4.0L 4WD.
I've just finished a fairly extensive build on a custom suspension system and took it out for a road test yesterday. Everything related to the suspension/chassis worked amazing!
That said though... Cause of some modifications I've made to the engine compartment and shock mounting setup, I was left with only 1 option of mounting the air filter and that was on the drivers side between the radiator and the coolant overflow/window fluid tank. Now I was a bit skeptical about doing this worried that extending the harness may mess up the resistance in the harness cause I know some older vehicles engineered the harnesses this way but I went for it anyways. I added about a total of 12-15" of harness length to the MAF sensor. I soldered the harness, no goofy butt connectors or anything like that.
Now I finally got the truck ready for it's test drive. It was about 95-99 degrees here in Vegas yesterday. I first took it for a spin around the neighborhood. I've got an ENTIRE new front suspension system with a lot of custom work done. I was checkin for handling, brakes, clunks and noises, etc... I did NOTHING to the engine though other then unplugging and plugging back in a few harnesses and the MAF harness extension. It ran fine. So pulled it back in the drive, made a few suspension tweaks, double checked a few things and went for a road test to run an errand actually. Left the house, Did about 10 miles of city street driving. Stop lights, a little traffic down near the strip, etc... Everything great!!!
Ran into a store for about 30 minutes, came back out, fires up great. Take the long way home and hop on the freeway. Cruising along at about 70mph for about 10 or so miles. It's well past just being warmed up at this point and scooting along fine, like I said, we pushed 100 degrees today.
All of a sudden I'm loosing power... It doesn't just die instantly but I can tell it's sputtering and going down. I get off to the median and make a choice to coast it to the next offramp with the momentum I have. Get well off the freeway and figure it's gotta be wiring related cause I didn't do anything else. I check a couple plugs, nothing... Well, actually at this point, what it's doing is it'll start and idle but any throttle and it just about stalls, pops, sputters, backfires thru the intake, etc... After a bunch of wiggling it fires up though, I toss on my seat belt and pin it heading home using back city streets. It basically ends up to the point where it'll run normal for about 45-60 seconds, then falls on it's face. I coast to a stop, turn it off, wiggle wires, back in and go for another round. Takes me about 6-7 rounds of this to get to my driveway. Now I have to say, I'm not 100% sure wiggling the wires was doing anything. It was just a routine that was getting me closer to the comfort of my driveway so I did what worked, I could've possibly just turned it off for a minute and fired it back up and had the same results. At that point though, I just wanted back to my driveway.
In my driveway I look at the plugs I'd messed with during my suspension build. I find one with only 2 wires on it and they're both bare for about 3/8" right as they go into the plug!!! BINGO!!!! I can deal with this... Insulate them and figure game on! It fires right up in the drive so I decided to run to the store with it.
I make it about 1/2 mile and it's doing it again. CRAP!!! I jump thru the routine of wiggling wires still thinking it's gotta be related to that. I get back home.
I plug in a fairly decent OBD1 scanner I have. For some reason I've never been able to connect to do a engine running scan for as long as I've owned it but I've been able to do key on engine off scans.
The only code I pull is a 66. MAF voltage too low.
CRAP!!!! Is this due to my extended harness?
My hesitation with assuming that is why was I able to drive it for probably 20 minutes on the city streets problem free, then another 10-15 minutes on the highway problem free before it gave up? I'd have thought if it was related to my harness it would've been doing it from the get go, not 30-45 minutes into a test drive?
Thoughts? The expo has been sitting for about the last 6 weeks during my build. I have started it for a couple minutes probably about 3 times during that duration but didn't drive it at all, just let it idle up to temp and that's about it.
I've got another expo to rob parts from... I actually was going to pull that plug with the bare wire and splice it in as a replacement but the one on my other expo isn't using the same pins. My problem expo has only 2 of the 8 possible pins in use where my other is using like 6 of them. The other one is an auto trans though so I'm guessing that's the difference.
So, Code 66, MAF voltage below minimum, is it cause I extended my harness? If so, why did it take 30-45 minutes to start acting up? If it was a warm up issue I know darn well it was at full operating temps WELL before then.
The little reading I've done online this morning seems to be that a lot of the times code 66 is a vacuum related issue. Doesn't really make sense considering the code detail but then again, this isn't cutting edge technology either.
Any ideas?
Thanks,
Khris
