Fix your hesitation

[gtrjerry73]

I get the same thing, but only if I've been in stop-and-go (deadlocked) traffic for a while. It's gotten so bad that the car has died on me once. It was almost like the car ran out of gas - even though it was half full. I had to wait for over an hour for the car to cool down before I could start it again.

My car is doing exactly the same thing it seems the nicer I drive it the worse it gets if I'm just Rollin around at low Rpm not giving it any boost for like 20 mins or more it's gets pretty bad just hits a wall I thought my car actually stalled to me it sounds like tps sensor so I'm gonna test that clean it and go from ther I'll post if that fixes the issue it just worries me that it's extremely inconsistent

[Skym]

If it doesn't start for a hour it could be ignition module (one of the symptoms). Another is fuelpump. TPS just randomly stalls engine, but can be restarted straight away.

Replacing ignition module with a known good ignition module should help to see if it's a cause.

But the symptoms of hesitation (lack of fuel), stalling points towards the fuelpump or the wiring to fuelpump.

[gtrjerry73]

ya it didnt actually stall, just kinda felt like it (gas pedal did nothing) then would just kick back in and go like normal. hasnt had any issues starting at all. and the "hesitation" is very intermittent. ill be driving her to calgary probably on monday or tuesday and will see if i can get a better idea. when i get her back ill do all of these tests and definately adjust my tps sensor. thanks guys.

[johnZ32]

It's getting hotter out and my issue from last summer is returning, but worse. just while driving its like the engine just stops mid-stride. yesterday i counted it out and while driving at 80 km/h in fourth gear it "cut out" for 7 seconds. 7 seconds of nothing, held it WOT and nothing happened to the rpms. then it just suddenly comes back and drives like normal. it usually only "dies" mid drive for a second or two but it is happening more often now.
i have redone all the "Fix your hesitation" fixes this spring but to no avail.

Any ideas what else i can check. somebody has even thrown out there that is could be something in the transmission or clutch.
This issue is really killing my spirit and is making for a bad first experience with skylines still love em though

[gtrjerry73]

wow this is definately the exact same problem as i am having and will watch this thread for any updates. if anyone knows or has some insight into some things to try please by all means. dont let it effect how you feel towards your skyline johnz32. im sure it is something pretty simple. it usually is, just ends up being a pain to diagnose. but you said you did all the fixes? you did the throttle position sensor? becuase thats what i thought it would be.

[johnZ32]

ive been trying to figure out this issue for about a year now.
i check my TPS every couple days.

me and a buddy that owns a shop and works on skylines alot have it figured down to either A: CAS B: Igniter pack or C: MAF as i have checked/replaced everything else

i am borrowing his CAS on monday off his GTR to try out and i will let you know how it go via this thread.

[gtrjerry73]

I have a hunch that it could be the igniter pack. Have you tried the Maf or the cas yet?

[johnZ32]

yup, i've just finished checking/swaping those and no luck so far.
i am taping up my coilpacks tonight as they are arcing a bit under load.

[gtrjerry73]

Hmmm nasty little gremlin under the hood. A few ppl have said on Here that the fuel pump was a culprit for this. one guy even fixed the same issue with a fresh fuel filter, so I figure I'm gonna sit down some weekend when I'm at home (always out of town) and replace all of the little things ( tape coils, fuel filter, injector seals, yadda yadda) and then start replacing coils and resolder my mafs, and eventually even a new igniter :s fun fun fun

[Skym]

Process of elimination.

On my car I had TPS, o2 sensor, MAF, CAS failure, 2x coilpacks (due to incorrect sparkplugs), etc. MAF was the first failure and resoldered new MAF (inside square part) and haven't had a problem since replacing MAF. Worth the time spent on it, as now it's alot of fun to drive.

[gtrjerry73]

Ya I knew when I bought the car I was gonna end up replacing probably everything but the block eventually. And I don't think I'll be happy till she's pretty well brand new. Just wish I had the money to do everything at once lol

[needavdub]

Uhhhg, I'm having a hell of a time trying to figure out my my hesitation/miss @ WOT at higher RPMS. Like it's "breaking up" under boost. It was only doing it before at higher boost settings (13psi and higher), so I replaced the coils with Yellow Jackets and all was well. Pulled like a freight train at 16psi. Then one day it started doing this crap again. I changed the plugs, fuel filter, and fuel pump (MKIV Supra 290lph denso) and the miss is still there. It runs perfectly until WOT, I'm going to try a few other things on this list I guess, but this is really frustrating.

[Skym]

Probably sparkplug gap if missing at WOT only (factory is 1.1mm and most use 0.8mm) and one heatrange colder (PFR6A) due to engine running leaner (if rich due to bigger fuelpump, stock PFR5A sparkplug for RB20DET might work due to lower cylinder temps). Also doesn't hurt to check voltage to fuelpump, as engine could be going lean at WOT when tested on dyno. But if fuelpump is bigger than stock 135lph fuelpump, it should be the opposite and be rich (probably into 10's for A/F ratio) at mid to high rpm (retune engine with Nistune).


Most of the parts that failed on my car were parts that were meant to be replaced as part of routine maintenance. Previous owners never replaced the parts, so had to catchup on the maintenance. That's why you buy a car with full service history or close to it, as can see how it was serviced.

[needavdub]

Probably sparkplug gap if missing at WOT only (factory is 1.1mm and most use 0.8mm) and one heatrange colder (PFR6A) due to engine running leaner (if rich due to bigger fuelpump, stock PFR5A sparkplug for RB20DET might work due to lower cylinder temps). Also doesn't hurt to check voltage to fuelpump, as engine could be going lean at WOT when tested on dyno. But if fuelpump is bigger than stock 135lph fuelpump, it should be the opposite and be rich (probably into 10's for A/F ratio) at mid to high rpm (retune engine with Nistune).


Most of the parts that failed on my car were parts that were meant to be replaced as part of routine maintenance. Previous owners never replaced the parts, so had to catchup on the maintenance. That's why you buy a car with full service history or close to it, as can see how it was serviced.

I'm running NGK copper BKR7E's gapped at .8mm, my AFRs are at about 11.8:1 (Innovate LC-1 wideand) under boost. I haven't checked the voltage to the fuel pump, I just installed it (along with a new filter) last night. I figured I'd "hotwire" it so it get's the full 14v from the battery at all times. But somehow I doubt it'll make any difference. It was running awesome, then it wasn't. Something changed and I don't know what...

[Skym]

I assume it's a 7? heat range sparkplug your using and might be too cold. I ran a PFR6A sparkplug with similar A/F ratio (bigger turbo, etc). But if your ECU isn't tuned for that higher boost level, then it could be the problem.