89 SE 5 spd...The car was running like new...then all of a sudden idle RPMs went to 1500 and stuck there...car is overheating and cooling fans are not turning on...coupled with that...its misfiring at the same time at 1500 RPMs...

Also....if i turn off the engine...it gets flooded with gas...i have to take out the fuel pump fuse and crank it a few times and it starts up even with the fuel pump fuse OUT and idles at 1500 RPMs (while misfiring) until it dies out after a minute or so as it burns up the excess gas in the engine...

does anybody have any insight to this? the ECU brings up code 55 i.e all good

 

 

I would seek professional help on this one man...Pay like $50-75 and get it diagnosed at a reputable shop. Hopefully it's a DIY (do-it-yourself) job...

 

Hmmm. Now that I think about it, with a VG engine and the symptons that you are describing, you may want to take a look at your rotor and distributor cap. If you have never replace them, that COULD cause your problem.

See, if you flood the engine, then we know that you have plenty of fuel--therefore, we can for the most part eliminate the injectors. Again, if the engine is flooded, the fuel is not being burned. Since the rotor and distributor cap are not really controlled or monitored by the ECU, you will not see any ECU codes. Follow me?

Other items could be the spark plugs or wires. Especially if they have not been changed before. Another component could be the ignition coil. Even though these do not go bad very often, it is a possible source of the problem. Again, each of these MAY NOT flag an ECU code.

Anyone else out there with anymore info?

 

a few days ago this had happened and i had checked the ECU and it blinked code 13...engine temperature sensor....that was in the evening...the next morning i checked ECU and it gave 55 again...and car drove perfect.

engine temp sensor could be going bad....that would tell why fans dont turn on...and since the car thinks the coolant is cold all the time it will try to warm it up by idling higher like starting in a cold morning. I will change the sensor anyway since i got a code for it once although not anymore.

The perplexing part is the misfiring...its highly likely its the rotor for the misfiring ... cuz i was hearing it squeak for a second when it turned when i turned the ignition to on...right before starting the car. but thats not happening anymore.

ALSO..when i press the accelerator...the engine stumbles (RPMs drop and pickup) and at around 2500 RPMs engine runs fine again. could it be the Idle Air control valve that is dirty and not enough air is going into the engine to allow it to ignite the gas properly at idle?

its either the rotor or the IACV. but if someone has any input about this please do let me know.

 

Check your FPR. It could be worn out. I've narrowed pretty much all my problems (with exception to a few things caused by a worn out/dirty IACV) down to my FPR being worn out. Basically, what is happening to mine is it is worn out and flowing wide open. Because of this, it runs REALLY rich on the low-end and can cause misfiring because of this. On a cold start, my engine will idle but try to keep dying so I have to rev it a little and then it will idle properly. I have the opposite problem at high rpm. Despite the fact that my FPR is causing my VG to run so rich at low rpm, at higher rpm I'm running lean due to the fact that it is worn and can't provide enough pressure for higher rpm. You guys having these problems should check your plugs and see if they are white. If so, that is an indicator that it is running lean. However, if you also can smell the gas on the plugs than I'd suggest checking the FPR because it could be the problem. For the longest time I couldn't figure out how it made any sense that my plugs were white, so I was running lean, yet I was running so rich sometimes the plugs would be dripping with gas when I pulled them! One result of this FPR problem is that running so rich on the low-end bogs the engine down and running lean on the high end has the same effect. So basically, it's causing my VG to have a power loss across most of the rpm band.

 

ques: whats do these abbrev. stand for? (IACV/FPR) And how much are they? And are they easy to replace yourself?

 

IACV = Idle Air Control Valve (square part on front right of VG intake manifold, not sure where it is on the VE)

FPR = Fuel Pressure regulator (right rear of VG intake manifold, not sure on VE)

The IACV w/ gasket is only about $140 from Courtesy Nissan, which is the cheapest deal I've found anywhere. Not sure on the price of the FPR because I'm just upgrading mine when I put my turbo setup on (Vortech 12:1). The IACV isn't too hard to do yourself though, the FPR can be a little complicated if you haven't done much work on your Maxima before. The IACV is easier since you can easily get to it from the front of the intake manifold. Though, the FPR is at the rear and can be a real pain to get to if you don't take the intake manifold off.

 

Shadow1198 Thanks for the 411and the quick response. Its greatly appreciated.

 

ok checked spark plugs....they have a greyish dust on them. i changed all of the plugs...wires and fuel and air filter a day before.

what about the cooling fans on the radiator....even if they FPR is going why wont the fans turn on ??

 

ok i checked the factory service manual...the ignition coil and crank angle sensor ARE infact connected to the ECU....mode 4 i think.

but there codes are not coming up.

can the oxygen sensor be the problem??