R33_GTS-t

I recently bought an R32 GTR. After about 20 to 30 minutes of running it starts cutting out, like hitting the rev limiter. I thought it was detonation but apparently that sounds like spanners rattling. Is this true? We changed the engine speed sensor since we suspected that this was the fault, since it would not go past 2400rpm even in neutral. This didn't help. The car also seems to have a lot of rolling resistance compared to the R33 GTSt, is this just the 4WD?

Any suggestions?

bonzelite

check the intake air temperature sensor.

actually, this sounds like a bad MAF. check the seal around the top perimeter of the MAF. if it is dry-rotted or cracked looking, you more than likely have moisture buildup in there. you have to replace the entire MAF by the way, not just the seal.

R33_GTS-t

Thanks. Is the MAF sensor the one just downstream of the air-filter box?

If so, I noticed a crack where the intake pipe joins the airbox earlier.

Will the misture build-up remain a problem and, if so, what causes it?

bonzelite

yes. the MAF is a square box on the intake tube just near the air box.

moisture builds up anyway, as in condensation (dew on the grass), as the atmosphere contains some level of humidity all of the time (except in extremely arid climates).

moisture in the intake manifold, as it heats up and expands in the fuel/air mixture, can potentially screw up your ignition timing, creating a mistimed spark event, ie, rough idle.

actually, the problem resembles bad injectors A LOT.

check your plugs and wires, too.

R33_GTS-t

Thanks again. I tried unplugging the top MAF and it was similar in effect but more jerky. What I'm experiencing is like someone applying the brakes as I apply the accelerator.

I understand the ECU is in the boot. What does it look like and where do I see the flashing fault code light?

bonzelite

ok. yes, a bad MAF will really jerk the car. to the point that it is not driveable.

your problem is sounding more and more like a bad injector. symptoms of that are a sudden drop in power, with some hesitation, but not violent like jerkiness. the car is driveable. sometimes, if the injector does still partially function, power will come back on briefly, then drop again, and the car goes sluggish. is this more like your problem?

you could also simply have a bad plug. take the plugs out one by one (leaving the others in), and check for corrosion or oil.

also, you may find the "dead" plug, one by one, as the engine idles, by disconnecting the plug wire: as you remove and replace each wire from the plug, and you come to disconnect a wire --and the engine remains idling the same, then that is the bad one. when removing a wire, and idle drops, that plug is good and functioning. this is a process of elimination.

for R32 GT-R, ECU is not in the boot (trunk). it is inside the left under-dash area, within the center console. the light is on the front of the unit next to the idle speed adj. screw.

by the way, you can test for a bad injector, using the same method as the plugs, without using the ECU diagnostic. have the engine idle and remove and replace, one by one, each injector connector. do it until you find the bad one when the idle remains the same upon removal of the connector.
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your problem may not be any of these, but it can't hurt to check. you will have to anyway. or somebody else will.

for the future, you may want to get a datalogger, as well. and since you just got the car, it follows to reason that you should perform a full tune-up on her. replace all wires, plugs, fluids, filters, O2 sensor, EGR, PCV, on and on... everything. this way, after the tune up, if she still runs ****, you have eliminated a lot of variables.

buzzard

coolant temp sensor is likely.

R33_GTS-t

Problem fixed. It was a faulty MAF.

Thanks folks!

bonzelite

good. the MAF was my first assumption. i knew it had to be one of the things i mentioned. i've had the same things all happen.

exhale

Do you have a Skyline? Your profile says a Galant.