First off thanks for all your previous support. I am posting this as a means to find closure to this issue I have been having.
A few months back, My 1jz Single put down just a pinch over 400whp at 22 psi. I would say it was on a great tune running simple 550s and an AFC combo. This is not a DD and remains in the garage until the weekends. SOoo not long after that, I started realizing it would hesitate at that 20+, then a week or so later, I would turn the boost down to 18..it boosted fine then hesitated again until I finally got the boost down to 15psi last night.
Now here are the troubleshooting steps I performed during this time:
Fuel Filter
Fresh tank of 93
Injector Cleaner
Plugs NGK Coppers Gapped to the original gap of .025... Noticed hesitation still prevalent so I lowered it by .02 until I my current gap of .022. Still unable to boost higher than 15.
Changed plugs again to another set.. same issues occured at anything above 15psi.
Pressurized intercooler and intake system, but there were no leaks.
Fuel pressure has no been changed from previous tune.
Again- no changes were made... simply took the car out one weekend and hesitation kept occuring until i lowered the boost down
SOoo based off what I have read, I decided to check all my coils for cracks. I cleaned them and found absolutely no cracks, so just to be on the safe side, I did the 3m electrical tape fix JUST to see if it would help. I went out for a spin and there was absolutely no difference. It boosts great up until 14-15psi and holds a steady 12.1 - 12.3 on the AF gauge with absolutely no missing whatsoever and no hesitation.... SO i question why no boost like before. The engine has always remainded dry and never degreased or sprayed with water especially in the Spark Plug Channel....NEVER.
Then I went out for another spin and started further troubleshooting...At anything above 15psi... It leans out dramatically on the AF gauge and NO MATTER how much fuel I add on the AFC, it just doesnt fix the issue. This of course happens when its hesitating so I do see a correlation between the misfire and the eratic AF readings.. So again, anything around 15 psi and below..it pulls clean and nice all the way to 7k. No smoke, no smells nothing..Just perfect. But anything above it Is completely a shit fest of hesitation and stumbling. Second gear on a roll would break the wheels loose constantly and 3rd at times would have to fight not to break loose on top end but now, it cant even break second gear loose.
I have a precision t61 and no more than 45k on the motor with supporting mods. Clutch holds good and plenty but damn i miss having that power I once had.
Thoughts for myself:
1. Is it possible my gap is too small? The gap is the same as the last good plugs and the absolute same NGK Coppers. 5167's I believe with a heat range of 7.
2. Are my coils bad? I plugged them back in and checked all the connectors ensuring I had just enough dielectric grease in there. Terminals dont look burnt on either end. I had no cracks on mine and they have been wrapped but I know that usually cant be an excuse.
Any suggestions you guys can provide would greatly be appreciated.. Im stuck trying to figure this out. Thanks in advance as always.
A few months back, My 1jz Single put down just a pinch over 400whp at 22 psi. I would say it was on a great tune running simple 550s and an AFC combo. This is not a DD and remains in the garage until the weekends. SOoo not long after that, I started realizing it would hesitate at that 20+, then a week or so later, I would turn the boost down to 18..it boosted fine then hesitated again until I finally got the boost down to 15psi last night.
Now here are the troubleshooting steps I performed during this time:
Fuel Filter
Fresh tank of 93
Injector Cleaner
Plugs NGK Coppers Gapped to the original gap of .025... Noticed hesitation still prevalent so I lowered it by .02 until I my current gap of .022. Still unable to boost higher than 15.
Changed plugs again to another set.. same issues occured at anything above 15psi.
Pressurized intercooler and intake system, but there were no leaks.
Fuel pressure has no been changed from previous tune.
Again- no changes were made... simply took the car out one weekend and hesitation kept occuring until i lowered the boost down
SOoo based off what I have read, I decided to check all my coils for cracks. I cleaned them and found absolutely no cracks, so just to be on the safe side, I did the 3m electrical tape fix JUST to see if it would help. I went out for a spin and there was absolutely no difference. It boosts great up until 14-15psi and holds a steady 12.1 - 12.3 on the AF gauge with absolutely no missing whatsoever and no hesitation.... SO i question why no boost like before. The engine has always remainded dry and never degreased or sprayed with water especially in the Spark Plug Channel....NEVER.
Then I went out for another spin and started further troubleshooting...At anything above 15psi... It leans out dramatically on the AF gauge and NO MATTER how much fuel I add on the AFC, it just doesnt fix the issue. This of course happens when its hesitating so I do see a correlation between the misfire and the eratic AF readings.. So again, anything around 15 psi and below..it pulls clean and nice all the way to 7k. No smoke, no smells nothing..Just perfect. But anything above it Is completely a shit fest of hesitation and stumbling. Second gear on a roll would break the wheels loose constantly and 3rd at times would have to fight not to break loose on top end but now, it cant even break second gear loose.
I have a precision t61 and no more than 45k on the motor with supporting mods. Clutch holds good and plenty but damn i miss having that power I once had.
Thoughts for myself:
1. Is it possible my gap is too small? The gap is the same as the last good plugs and the absolute same NGK Coppers. 5167's I believe with a heat range of 7.
2. Are my coils bad? I plugged them back in and checked all the connectors ensuring I had just enough dielectric grease in there. Terminals dont look burnt on either end. I had no cracks on mine and they have been wrapped but I know that usually cant be an excuse.
Any suggestions you guys can provide would greatly be appreciated.. Im stuck trying to figure this out. Thanks in advance as always.
Also, your af's are a bit to lean, everyone who want to keep there engine, run 11.5 at most. But if your tuner is set on 12.2-12.5 it should be fine.