[1997XETruck]

1997 XE 2.4 with M/T...

My truck has slowly developed a problem at idle, but only when the A/C is off. I noticed it most last night... with the truck is stopped and at idle the tach. was bouncing from somewhere around 400 to 700 RPM. If I turn the A/C on, the idle is smooth and at about 1000 RPM. The idle bounces about twice per second - as though the truck is choking down and then the ECU is trying to fix it through the IAC/AAC valve. My guess is that the idle setting when the compressor is on is covering up whatever other problem is there.

I recently replaced the spark plugs with OEM plugs, and installed a new OEM fuel filter. I also checked it with a Consult adaptor and my laptop using Nissan ScanTech software. The power balance looked good, so I don't think it's injector related. Also no stored codes...

Any suggestions?

Thanks!

Heath

 

[zanegrey]

was it doing it b4 u changed the plugs??

check gap on plugs and maybe it is time for wires and cap /rotor...

 

[mini hardbody]

sounds like the same problem my buddy has, its the egr valve on his that is causing the problem

 

[1997XETruck]

Same sort of issue before the plugs. OEM Wires and distributor cap and rotor have about 30k on them - but they could need to be replaced again. Interesting thought on the EGR. I guess if the EGR is sticking, it's possible that the IAC/AAC is trying to compensate and then cycles for some reason. It ran fine today, so I will try to hook up the laptop the next time it starts acting up.

Heath

 

[antoniou]

check the are vacum valves when a\c is you have 12v in one of the 2 wires

 

[Nissanpickup]

i dont know why the egr valve would be the cause i pulled mine off and made a block of plate on the intake for it and mine runs fine i also pulled the ac and it idles at 800 in or out of gear and if u dont mind me asking where did u get the nissan scantech software i would love to have a copy of it also with that program can you tune the ecu for more fuel because all imports made an agrement to for their vehicle to not go faster that 300km/h (186mph) and all they did was tune the ecu but then susuki broke the agrement with the hyabusa

 

[dvdswanson]

ck the TPS, MAF and IAC, these are most common idle culprits. when the a/c kicks on it automaticly raises the idle. when the compressor does its cycling does it do it then (when cycled off)?

 

[1997XETruck]

Thanks for all of the suggestions guys! I haven't had the problem again, so I haven't had a chance to do any more testing...gotta love intermittant issues.

Heath