R32 Gtr - Hesitates While Cruising

[chances]

Long story short -

1. car spluttering / not running smoothly when cruising in 4th gear @ 2800rpm (after 20 mins of driving / car warm) plus leaky injectors were getting really bad.

2. next day melted a coil.

3. changed all the injectors & replaced the coil - all good again.

4. took it for a drive today - same problem after the car is warm ... revs fine and goes hard still anytime but when im cruisin the car jumps back and fourth a little and runs all crappy.

ok ... so its not the injectors, could be one of the other coils but i just wanted to know if the airflow meters would be affected by heat ? ive only just put on a set of hks airpods and ive noticed all the piping and the outside of the airpods were really hot after i come home, just wanna know if this could be the problem or perhaps an 02 sensor ? but yea the car runs perfect untill its warmed up ... then it just wont cruise nicely

Thanks

Max

[Crimpage]

Are the pods sheilded at all? Like you said, it could be the heat coming in through the pods

[SLIPPERY]

ive got the same problem

i doubt it would be o2 sensors because if they were faulty, ie, not doing their job, then they wouldnt be leaning out the mixture on cruise. thus keeping the mixture richer and smoother.

i think the jerkiness i get with my gtr is due to dirty injectors having a terrible spray pattern at lower fuel pressures (ie cruising) from running a few tanks of petrol bloody low. however, you said youve changed the injectors

to be an AFM problem, you would feel the 'cutting in' and 'out' on all loads.

i reckon its still a fuel delivery problem. hows your fuel filter? changed it recently? these old gtrs have quite a bit of gunk sitting in the bottom of the tank by now.

the reason the car runs fine when its cold is that the mixture is enrichened by the ecu which compensates for the low fuel delivery when the car is warm

Edited July 20, 2006 by SLIPPERY

[chances]

Well i just purchased the injectors 2nd hang which were sitting for a little while, not sure how long... and put them straight in, ill just have to get them taken out and cleaned ... weird thing is that it done the same thing with the previous injectors which were leaking fuel internaly really bad, this is what i thought the problem was ...

I might check out the fuel filter tomorrow ??

Perhaps another coil might be on its way out ??

Ill just have to get it checked out on a dyno or something ...

ive got the same problem

i doubt it would be o2 sensors because if they were faulty, ie, not doing their job, then they wouldnt be leaning out the mixture on cruise. thus keeping the mixture richer and smoother.

i think the jerkiness i get with my gtr is due to dirty injectors having a terrible spray pattern at lower fuel pressures (ie cruising) from running a few tanks of petrol bloody low. however, you said youve changed the injectors

to be an AFM problem, you would feel the 'cutting in' and 'out' on all loads.

i reckon its still a fuel delivery problem. hows your fuel filter? changed it recently? these old gtrs have quite a bit of gunk sitting in the bottom of the tank by now.

the reason the car runs fine when its cold is that the mixture is enrichened by the ecu which compensates for the low fuel delivery when the car is warm

[SLIPPERY]

u should always get 2nd hand injectors cleaned before putting them in. FWIW, my injectors dont leak at all and i get the jerkiness so its not related to a leak, rather the squirter being a little clogged.

injectors can be cleaned for $20 each with a print out of before and after flow rate, plus a spray pattern pic.

i changed my fuel filter last week and its a 'tiny' bit better.

[T04GTR]

o2 sensors

[T04GTR]

if its ok when cold.

just to be sure unplug the o2 sensors and see.

mine did the same thing till i realised they were the wrong 02 sensors :

[T04GTR]

yep. UNPLUG THE 02 SENSORS AND GO FOR A DRIVE

[R34 VSPEC]

Long story short -

1. car spluttering / not running smoothly when cruising in 4th gear @ 2800rpm (after 20 mins of driving / car warm) plus leaky injectors were getting really bad.

2. next day melted a coil.

3. changed all the injectors & replaced the coil - all good again.

4. took it for a drive today - same problem after the car is warm ... revs fine and goes hard still anytime but when im cruisin the car jumps back and fourth a little and runs all crappy.

ok ... so its not the injectors, could be one of the other coils but i just wanted to know if the airflow meters would be affected by heat ? ive only just put on a set of hks airpods and ive noticed all the piping and the outside of the airpods were really hot after i come home, just wanna know if this could be the problem or perhaps an 02 sensor ? but yea the car runs perfect untill its warmed up ... then it just wont cruise nicely

Thanks

Max

Mate, I had similar problems, would only notice it when car is hot or being driven for a while. No doubt leaking injectors etc would contribute in your case.

Had my car checked out with a fault code finder and air flow meters were both on their way out...not completely f#%ed yet but was told would eventually die. Both of them!!!....reading different voltages above and sometimes below the norm.

Had both replace..expensive exercise and now car is running fine...no more jumpimg back and forth and lossing power.

As for the heat towards the AFM, I was told the crank case ventilation with hot engine oil mixing with air being redirected back through the air inlet causes this contamination in the air inlet and sometimes or over time the oil/heat can affect the AFMS. Recommeded an oil catch can setup to eliminate this contamination.

Oh yes, my 02 sensors weren't spot on either but was told this should not affect the driving of the car to the extend of not responding to the throttle when this happens and I would loss fuel injector signals. AFM stuffing up, telling the car that no air is coming in so fuel supply stops momentarily...car runs crap, jerks back and fourth for a few seconds, sometimes longer and then picks up again. I could actually see no fuel signal on the multi display screen when this happens.

Anyway, just something I've experienced and was told by my mechanic....that's my 2cents.

Good Luck

[chances]

Naa thats awesome, ill just have to get my hands on a multimeter and have a play with the AFM's ...

theres heaps of things for me to check / replace / fix hehe

Thanks for all the replies

Mate, I had similar problems, would only notice it when car is hot or being driven for a while. No doubt leaking injectors etc would contribute in your case.

Had my car checked out with a fault code finder and air flow meters were both on their way out...not completely f#%ed yet but was told would eventually die. Both of them!!!....reading different voltages above and sometimes below the norm.

Had both replace..expensive exercise and now car is running fine...no more jumpimg back and forth and lossing power.

As for the heat towards the AFM, I was told the crank case ventilation with hot engine oil mixing with air being redirected back through the air inlet causes this contamination in the air inlet and sometimes or over time the oil/heat can affect the AFMS. Recommeded an oil catch can setup to eliminate this contamination.

Oh yes, my 02 sensors weren't spot on either but was told this should not affect the driving of the car to the extend of not responding to the throttle when this happens and I would loss fuel injector signals. AFM stuffing up, telling the car that no air is coming in so fuel supply stops momentarily...car runs crap, jerks back and fourth for a few seconds, sometimes longer and then picks up again. I could actually see no fuel signal on the multi display screen when this happens.

Anyway, just something I've experienced and was told by my mechanic....that's my 2cents.

Good Luck

[SLIPPERY]

i thought when AFM's read incorrectly that the mixture went richer rather than leaner ?

[T04GTR]

thats what i thought.

[T04GTR]

its not terably hard to unplug the o2 sensors and take it for a drive

thats ok i have know idea at all. i only work on them all day

[T04GTR]

32gtr uses titania 02 sensors which control light throttle a/f ratios

[Cool Hand Luke]

When an engine is running rich, it will run ok untill it warms up, then with the extra heat, will cause the engine to run super rich. I had a similar problem with my RB20. Piece of shit to drive, spluttering, cutting out. Turns out it had a small crack in the intercooler, wich with the afm's was causing it to run rich, and also at times, max the standard afm because of the amount of air it was thinking it was reading. Its worth a look and do a leak check..

[T04GTR]

un plug them lol

02 sen

[Risking]

un plug them lol

02 sen

It gets rather frustrating when people refuse to listen to good advise doesn't it!!!

Un plug the sensors and take the thing for a drive. Why do you think its running rich??

O2 sensor feedback perhaps??

Unplug the sensors it will take them out of the equasion and my money is on the thing running fine just as T04GTR has suggested.

[T04GTR]

yeah. i rekon just replace everything and spend hours chasing your tale till you magicly fix it

[chances]

Yea yea so anyway whats the deal ?? drive the car for 20 mins till it starts playin up and then unplug the o2 sensor ? or do it before?? is it hard to get too ? or will i have to take it out beforehand and take it for a drive ???

yeah. i rekon just replace everything and spend hours chasing your tale till you magicly fix it

[SLIPPERY]

do it in the garage before you start the car. you dont have to wait for 20 mins before you do it.

we all wanna know how it goes!

you dont need to take them out...just unplug their electrical plugs and go for a drive