Fix your hesitation

[gtrjerry73]

Not sure if you have tried this but the idle air control valve can be the cause of a wandering idle and can make the car stall as well

[cnruff]

still having this issue about stalling. i did everything on this thread and when i check my sensors thru power fc handheld i notice my o2 sensor 1 is fluctuating in voltage it will go from 4.04 to even 0.00v is that mean my o2 is on its way out? should it stay at 4.04 all the time? thanks

[specialedition]

I have a question, I just finished testing my coilpacks they tested at 1.0-1.2 ohms does this mean they are finished and need to be replaced? Car idles nicely and drives nice except under high boost.

[BigJamal88]

Hey ! I just wanna thank the person who did the write up, and i wanna thank Gtrc for guiding me through to fix my hesitation. After a long battle, i finally fixed my car after a year. My car hesitated under Wot and it was horrible. I regapped the plugs to 1.1, and after i did that, my car wouldnt hold idle, so we cleaned the throttle body, and adjusted the tps, and after that my car hauls ass now. Its a gts4 with minor mods. Stock boost. I reccomend checking ecu for codes. And id like to thank eveveryone once again for help !

Merry christmas!!

[kelaog]

RE: you're welcome

I'm glad to see this post has gotten some use out of it. After receiving a few calls and a dozen text messages about fixing skylines I thought I'd come on here and let everyone know that I've been out of the scene officially for about 4 years now.

I'm in University 3/4 years completed in Mechanical Engineering. It is doubtful I'll buy another skyline with maybe the exception of an R34. Depends :P So if our paths cross later in life, say hello.

Regards,

Andrew

[skylinebeginner]

my rb25gtst was doin something like this but it was -1 - +9 so i think it might be doing it cause the air was thin and i was over boosting and leaning myself out .. so first gear was good got rpm quick then second gear around 3500 - 3900 it would start sputtering and around 6200 - 6600 it would clear out and rev the res of the way but only on 75 - 100 % throttle...

[needavdub]

I should probably have posted this before, but I finally fixed my misfire after over a year of agonizing frustration. I tried EVERYTHING on this list and still was unable to fix the problem. When the problem first started happening I suspected a bad coil pack, but ruled them out because they were brand new Yellow Jackets. After exhausting all other options I bought one new yellow jacket to swap in one cylinder at a time. And sure enough that fixed it. I'm not sure exactly what caused it to fail, it looked brand new still because it was. But I swapped the old coils with the new one one at a time and when I made it to cylinder #3 the misfire disappeared all together and the car pulled like a freight train to 8k @18psi again. The only thing I can thing is that my woefully old and brittle coil pack harness may have ruined it (since been replaced). But it just goes to show that you can't rule out the obvious just because a part is new.

Disclaimer: This is by no means bad mouthing Yellow Jackets or their distributor, I think what happened to me is a VERY rare occurrence, and I still recommend them highly and think they were one of the best mods I've done to my RB.

[jimBNR32]

little help if possible
spec, forged r32 gtr, nismo afms, stock ignition, bkr7e (0.8mm), powerFC, nismo fuel pump (wired off battery), sard 700s, about the only important things werth mentioning.

symptoms;

missing at idle

after car is warm, if i sit at idle, i notice on my commander unit that the battery voltage drops slightly, starting at 13.7v, and drops gradually by like 0.3vs and i notice my afrs getting leaner and leaner. quick rev brings voltage up and in turn afrs. but back to idle again is very lean, 16s, 17s then off the chart.
when i put my headlights on, commander shows very low 12.9-13.0v and my afrs go mental lean and it stalls

before this i had been driving the car fine, boosting well, soon as i parked up, putting car in the garage, this happened.


any ideas??


only things ive checked is battery, which is 11.8v non running, but when car started shows 14.2v. (so alt ok? ) commander generally shows about 0.7v less than what the battery is seeing.

definatly feels to me like the fuel pump is loosing power (gradually got less loud, especially when i put my headlights on), this im guessing ment less power to fuel pump (tho ive yet to check voltage at pump), and in turn less fuel pressure? causing leaning out and stalling??

initally i was looking to find out why the car died when i put the headlights on, now i know its because im loosing 0.5v instantly at the commander and it must be dropping the fueling???

had no missing before and during the drive!
on cold start its fine, im guessing because revs are 1200-1400rpm at this point and giving the car plenty of voltage.


should the pfc be seeing more than 13.3-13.5ish volts at warm idle??
it seems odd to me to be reading a good 0.7v less than when measuring voltage at the battery with a multimeter?


where to start given the info above???


thanks

[SpeedDemon]

times 2 on the fuel pump fixed 95 percent of my problems i know what you mean feels like a new car lol and a set of fresh plugs never hurt

[99_SI]

High rpm stuttering=lack of backpressure guys. Have been trying everything here and nothing worked. I am a class A technician and have been discussing tis with some of my fellow techs and a lot of diesel techs have advised me that turbochargers on diesel engines need backpressure to achieve top boost. Try it , i have put my catalytic back on and what a difference. Steady pulling in all gears all the way to 7K. No stuttering and no more of that rotten egg smell. On a side note i would not touch the APP/TPS sensor. Rbs have a hi idle switch which is within 0.2v difference when looking at the data. If adjust above 0.4V at idle you will have a high idle all the time. I am using Nissan ScanTech and R33 Skyline service manual. Have been through all parameters and found that at 0.6v Hi idle kicks in. Hope this helps.

[99_SI]

Fix your hesitation

Wow I'm the last one to chime in. We'll it was good for a bit and then it was back again. Worse when ambient air dropped. Since I got a 25 I tried bunch of things on this forum with little success. Eliminated all the hoses as boost leak suspects, replaced plenum gasket with cometic one( while had it off my machine shop friend polished it for me )
Now I read somewhere on this forum someone had this infamous problem all due to apexi hair filter . I have one of those and also have an hks shroom. So for the heck of it I decided to swap me out last night. And BANG! I blew my motor.....no...just joking. Whadayaknow ....junk apexi filter restricting airflow and making it run 10afr and coughing and such. Wow. I've seen my share of picky engines but I think own tops them all. Now makes me think back to two years ago when I bought the thing why the guy didn't wanna red line it for me before the sale....thanks gtrc and all it's members for most useful info.


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