I put my Supra on the dyno yesterday and around 3200 rpms while driving the car would act like it's 2-stepping and then it would clear up above 3200 rpms and run fine and rev to 7k without any problems. When we gave the motor light throttle the 2-stepping would be slower than when we gave the engine more throttle. When we did a manual test of the injectors with my ViPEC V88 in batch fire mode injectors 4,5 and 6 didn't work, but when the same test was done in sequential mode the injectors worked fine. I've changed my injectors to aftermarket Bosch top feed injectors, changed to 1zzfe coils, and installed a ViPEC V88 with a PnP jumper harness built by John Reed.
1J acting like it's 2-stepping while driving and going lean in a certain RPM band
- Thread starter honestabe
- Start date
here is a link to my youtube page, a couple of the videos show the problem in action
http://www.youtube.com/watch?v=2aWZjHseDy8
http://www.youtube.com/watch?v=bgudBSnlrN8
http://www.youtube.com/watch?v=-zXRkqv4J7o
http://www.youtube.com/watch?v=2aWZjHseDy8
http://www.youtube.com/watch?v=bgudBSnlrN8
http://www.youtube.com/watch?v=-zXRkqv4J7o
when watching the map it looked like it was mainly in 1 cell that this problem would presist, auto tune feature wouldnt fix the problem either. across the board of the fuel table the cell numbers ranged from about 30-50 at the 3200 rpm they had tried to compensate it to like 70 and it just wasnt adding any more fuel there. but when there was fuel added below 3200 and force it to run rich it actually moved the problem from 3200 to like 4000 rpm. idk if adam mentioned but at 3200 it was leaning out reading 18 on the dyno at least when it did the bad sputter. but any rpm before and after was perfect sounding.
do you have a fuel pressure gauge? i had a similar issue, and i kept dumping fuel, and it was still going lean till one of the guys at the dyno was like "your fuel pressure is dropping", and that was it. what are your fuel mods? 1 pump or 2? 12v mod ?
Yes I do. Aeromotive FPR. I have 2 fuel pumps. 1 Walbro 255 in tank and another in-line that Bill Bowering helped me wire in. I also have the 12v mod. In the engine bay, I have the FPR feeding into a -8 fuel rail, then to a fuel dampener bypass hose connected to the return line. The fuel pressure was going up and down, ranging from 37-43. I need to have another look at it.
adam im pretty certain that the fuel pressure was set to i think 43 and it would increase with hard throttle but it never dropped. also i dont think he mentioned this but we had installed a new vipec to make sure that wasnt that also. and the last thing we were trying to do was get a new map sensor but couldnt find one in stock that was in spec or not broken lol
Ah. I've been very stressed out and tired since Saturday morning. They're taking off my intake manifold today and tomorrow and checking the wiring. Bob's 99% sure it's my wiring and that I have a couple wires crossed.
well lets all cross our fingers and hope this is the problem. oh btw adam ill probably be staying in tacoma till the end of next week now lol. so i should be in the area when you are getting the tuning done and ill get the videos uploaded. the youtube videos for some reason downed the quality dont know why <youtube newb
Wouldn't rev to 7k if it had a wiring issue
"Lean" is often confusing as if you have a misfire it will be pumping unburnt fuel into the 02 sensor and read lean when in fact the engine isnt.
I would be going through all of the Vipec's settings and compensations as it sounds like a limiter setting is on somewhere.
"Lean" is often confusing as if you have a misfire it will be pumping unburnt fuel into the 02 sensor and read lean when in fact the engine isnt.
I would be going through all of the Vipec's settings and compensations as it sounds like a limiter setting is on somewhere.
well i had brought that up to them when it was doing that. he made sure that all of the launch settings were off. and if it were a rev limit at 3200 it shouldn't go past 3200 then lol.
Awesome Trevor. Bob and Bill will figure it out. It's very strange that it only behaves like this at 1 certain rpm, and is fine elsewhere. It was very odd when it cured itself suddenly temporarily. Along with the pressure blow-back (or whatever it was called) going through the air filter.
maybe you just need a new flux capacitor, they have them for good prices on ebay normally pretty often.
http://cgi.ebay.com/BTTF-Flux-Capac...emQQptZLH_DefaultDomain_0?hash=item2eac35bb60
http://cgi.ebay.com/BTTF-Flux-Capac...emQQptZLH_DefaultDomain_0?hash=item2eac35bb60
LOL Trevor. I just got off the phone with Bob, my knock-off MAP sensor tests good but any other MAP sensor they try (new one from Chevy dealership, military grade, and another one) all test bad. WTF???? The shop is taking off my intake manifold tomorrow to test my harness. There goes the rest of my cash.
Big time. Tomorrow will finish off the $1300 I had set aside for tuning. My only saving grace is that Bob isn't charging me for all the hours him and his crew are putting into my Supra. Most likely I'll have to have Trey tow my Supra back to my place until I have the cash needed to get tuned again, probably a month from now. Maybe I'll get lucky and get a loan from someone so I can get my Supra tuned.
Bit of a n00b trap Adam, I NEVER take my car to the dyno till I have it 99% "there" and make sure NOTHING is going to fall off, break, blow up and not perform as expected.
The simplest of issues will chew dyno time like you wouldn't believe and every minute spent NOT tuning is money pissed up against the wall.
Hope the boys get it sorted for you.
The simplest of issues will chew dyno time like you wouldn't believe and every minute spent NOT tuning is money pissed up against the wall.
Hope the boys get it sorted for you.
Ian, I wouldn't have the slightest clue what to look at or how to even check it in the wiring. Most of what they're doing is well above my head. Hell, I can barely use my multi-meter
Of course. Yesterday they took off the intake manifold and checked my wiring, the injectors were all wired in correctly and in the propper order. So the engine harness has been ruled out as being faulty. Today they're checking the CPS and TPS and the off chance they are out of whack.