70challenger
04-29-2007, 11:18 PM
Car: Turbocharged KA24DE 95 Nissan 240sx, Apexi SAFCII, Walbro Fuel Pump, upgraded injectors, FMIC, Innovate LC-1 Wideband
So here is the whole story, I was at a driving school, and at the end of the day I noticed my idle was a little off, dropped down about 100 rpm or so and the car was becoming a little difficult to start, I would turn the key and it would start and die, so when I would start it I would blip the throttle then hold it at 2000 rpm then it would idle down a hundred less but then was more or less fine. Well I drove the car through a few puddles at the event, and the track was full of loose dirt so I got my K&N pretty dirty (its fairly exposed), so I was associating this with the lowered idle. So I drove the car home, and parked it. The next day I had an AutoX event so I decided to clean the filter for a fresh start. So I pulled the filter and connecting pipe off, and in the process two wires poped off (I think it’s the intake temp sensor wires, its on the same harness as the MAF connector), but I put the wires back over their connectors and secured them in place with electrical tape. So I installed the new filter, I went to start the car, and it sounded like a Harley, missing and popping and wouldn’t idle for anything, running super rich. I could free rev it but I was doused with a cloud of black smoke. I thought maybe a quick run around the block would clear it up, 2 blocks later it starts acting normal again, I am thinking “good, what ever that was about must have passed” but then a few blocks into my return trip the same bogging and surging reappears and I am blipping the throttle and clutch like crazy to keep the car alive and rolling forward.
So darn, I pull off the MAF unit thinking that maybe there is some residue in there causing a false reading, so I spray the unit down with a suitable electronic parts cleaner, I reinstall the unit, and bam, same thing is happening. Crap, I play around and find that with the MAF unplugged its running better (but not by much but at least it will hold a rough idle without dying) but the second I plug in the MAF it dies instantly. I left the car alone for awhile and walked to the AutoX event to watch my friend race, when I came back to the car about 2 hours later the thing would not even fire, after checking the spark with a screw driver in the plug wire hole I found I had good spark in the wires, but the plugs were totally fouled, so I bought new plugs, and the car started but still with the popping, harley sounding rough idle and rich afr.
The car, according to the Innovate LC-1 Wideband is running super rich. I tried compensating by lowering the fuel on my apexi unit just to get the car home, but even when I told the apexi unit -50% on the lower RPM ranges the afr didn’t even budge (somewhere around 8 AFR). So its running like garbage, I had to limp it a few blocks with the MAF unplugged to a hotel where I would have to stay the night until a friend with a tow dolley could pick me up the next morning, and that’s where I am now. Another weird thing is that the vacuum gauge on my Greddy boost controller and my Autometer boost gauge are reading higher than usual, usually at idle the Greddy reads -99 and the Autometer -20 PSI, but now its -95 to -87 on the Greddy and about -17 on the Autometer at idle?! Another weird thing, when I had to limp the car to the hotel it would loose vacuum very fast I would get it rolling at about 10 mph and 1500 rpm and when I would go to shift (had to stay out of the higher rpm’s to prevent bogging) the HKS BOV could be herd very loud, and the greddy unit would read -21 at that 1500 rpm with light throttle where it should be something like -70 to -64.
Then if it made it past 1500 rpm it would bog then surge then bog. Something seriously wrong is going on here, and I have no idea what it is. I checked for vacuum leaks and couldn’t find any, there is good spark, its just running incredibly rich, and I don’t know why, the only thing I found was a very small leak in the gasket between the turbo and the exhaust manifold. What should I be looking for, why is the computer telling the car to dump so much fuel? Sorry for the novel but I wanted to give you a clear understanding of the situation. Seeing as I am 180 miles from home, and any ideas would be great for when I get back or anything I can try to keep my friend from having to put the additional 360 miles on his driving rig just to help me out.
The thing that really stumps me is it was a little low on idle and hard to start, but then after sitting overnight the car when to pieces in a hurry… WHY? I checked the fuel flow from the walbro inline pump, and it started strong and lessened a little bit (like a steady pour) into an empty water bottle container, the fuel didn’t show any signs of water in it, I was going to change the fuel filter incase there was something with it not supplying enough pressure so the system was over compensating, but the parts store was closed by this point. I am stuck at a hotel with a broken 240, and the worst part is I have no idea what happened.
So here is the whole story, I was at a driving school, and at the end of the day I noticed my idle was a little off, dropped down about 100 rpm or so and the car was becoming a little difficult to start, I would turn the key and it would start and die, so when I would start it I would blip the throttle then hold it at 2000 rpm then it would idle down a hundred less but then was more or less fine. Well I drove the car through a few puddles at the event, and the track was full of loose dirt so I got my K&N pretty dirty (its fairly exposed), so I was associating this with the lowered idle. So I drove the car home, and parked it. The next day I had an AutoX event so I decided to clean the filter for a fresh start. So I pulled the filter and connecting pipe off, and in the process two wires poped off (I think it’s the intake temp sensor wires, its on the same harness as the MAF connector), but I put the wires back over their connectors and secured them in place with electrical tape. So I installed the new filter, I went to start the car, and it sounded like a Harley, missing and popping and wouldn’t idle for anything, running super rich. I could free rev it but I was doused with a cloud of black smoke. I thought maybe a quick run around the block would clear it up, 2 blocks later it starts acting normal again, I am thinking “good, what ever that was about must have passed” but then a few blocks into my return trip the same bogging and surging reappears and I am blipping the throttle and clutch like crazy to keep the car alive and rolling forward.
So darn, I pull off the MAF unit thinking that maybe there is some residue in there causing a false reading, so I spray the unit down with a suitable electronic parts cleaner, I reinstall the unit, and bam, same thing is happening. Crap, I play around and find that with the MAF unplugged its running better (but not by much but at least it will hold a rough idle without dying) but the second I plug in the MAF it dies instantly. I left the car alone for awhile and walked to the AutoX event to watch my friend race, when I came back to the car about 2 hours later the thing would not even fire, after checking the spark with a screw driver in the plug wire hole I found I had good spark in the wires, but the plugs were totally fouled, so I bought new plugs, and the car started but still with the popping, harley sounding rough idle and rich afr.
The car, according to the Innovate LC-1 Wideband is running super rich. I tried compensating by lowering the fuel on my apexi unit just to get the car home, but even when I told the apexi unit -50% on the lower RPM ranges the afr didn’t even budge (somewhere around 8 AFR). So its running like garbage, I had to limp it a few blocks with the MAF unplugged to a hotel where I would have to stay the night until a friend with a tow dolley could pick me up the next morning, and that’s where I am now. Another weird thing is that the vacuum gauge on my Greddy boost controller and my Autometer boost gauge are reading higher than usual, usually at idle the Greddy reads -99 and the Autometer -20 PSI, but now its -95 to -87 on the Greddy and about -17 on the Autometer at idle?! Another weird thing, when I had to limp the car to the hotel it would loose vacuum very fast I would get it rolling at about 10 mph and 1500 rpm and when I would go to shift (had to stay out of the higher rpm’s to prevent bogging) the HKS BOV could be herd very loud, and the greddy unit would read -21 at that 1500 rpm with light throttle where it should be something like -70 to -64.
Then if it made it past 1500 rpm it would bog then surge then bog. Something seriously wrong is going on here, and I have no idea what it is. I checked for vacuum leaks and couldn’t find any, there is good spark, its just running incredibly rich, and I don’t know why, the only thing I found was a very small leak in the gasket between the turbo and the exhaust manifold. What should I be looking for, why is the computer telling the car to dump so much fuel? Sorry for the novel but I wanted to give you a clear understanding of the situation. Seeing as I am 180 miles from home, and any ideas would be great for when I get back or anything I can try to keep my friend from having to put the additional 360 miles on his driving rig just to help me out.
The thing that really stumps me is it was a little low on idle and hard to start, but then after sitting overnight the car when to pieces in a hurry… WHY? I checked the fuel flow from the walbro inline pump, and it started strong and lessened a little bit (like a steady pour) into an empty water bottle container, the fuel didn’t show any signs of water in it, I was going to change the fuel filter incase there was something with it not supplying enough pressure so the system was over compensating, but the parts store was closed by this point. I am stuck at a hotel with a broken 240, and the worst part is I have no idea what happened.