Gents, started my car this morning but it was running rough, recently changed alternator and a day later the problem starts. RPM needle stays at 700 and any acceleration at all, the needle jumps to 4000 and goes no further. The engine isn't running at 4ooo rpm but the check engine lite is on. When I decelerate, car starts running rough again. Any ideas????

 

Since the check engine light is on,it has stored a problem code in the ecu

You need to check the codes in the ecu..

http://forums.maxima.org/showthread.php?t=311138

^^^^^^^^
Code info

Location of ecu..


Behind this panel on the passenger side

 

I got code 13 and 22. Tried another cooling sensor already, NO Joy. is the Fuel pump circuit located on the fuel pump????

 

Did you replace the coolant temp sensor,or the cylinder head temp sensor?

You should have replaced the cylinder head temp sensor,not the coolant temp sensor..



This is the chts location on the vg engine{sohc}

Chts location on the ve engine {dohc}

 

Also,multiple codes do not necessarily mean both parts are malfunctioning,one bad sensor can cause multiple codes to pop up..

 

Did you disconnect the negative when you did the alt job?

Just a guess, but check that your battery terminals are tight, clean the post and terminal with a wire brush and reconnect everything.

 

Mine won't start when warm. Fires first time then stumbles out. Got any ideas?

 

Fuel pump?

 

It seems to flood after it stalls. Won't start for like 20 minutes.

Strange thing is that it starts fine if it is cold.

 

I hate to sound like a noob but where is the pump and how hard is it to change?

 

i'll give my standard answer. Coolant Temp Sensor

 

I have put 3 pumps in my maxima[idiotzone crap]

It usually was fine at startup,then after a while it would just die out,i could usually bang on the top of the fuel pump cover with my fist to get it back going,but it was only a temporary fix..

You have to take out the back seats to access the fuel pump...

 

Hey guys,

Sorry to hijack the thread for a bit but regarding the ****/screw for turning on the ECM to obtain codes, i had a look on my car's one and above where the screw is, it says "Idle speed" or something along those lines, which to me seemed like it was of course some sort of adjustment for the engine's RPMs at idle... so i didnt want to fiddle with it...... whats the go there?

 

okay, I changed temp coolant and cylinder head temp sesors. Timing belt, water pump tensioner. No joy, Same symptoms as before except this time I got code 11,13,22. Once car starts, it idles at 700 rpm but rough and if you touch the gas at all, it jumps to 4000 rpm but the engine isn't running at 4000 rpm. any suggestions???? HELP

 

what are the symptoms if your MAF mafunctions?????

 

sounds like morely a faulty ECU. if the needle/or digi meter would jump to 4000 and the engine isnt doing so, sounds more of an electrical failure to me. Try swapping ECU's, from another maxima of the same year see if the problem persists.

something must have damaged when you changed your alternator. maybe ECU surged or something burned.

 

have you tried running with the alt disconnected?

 

No, should I unhook the connector and not the battery connectors

 

yeah you could do that but , by doing that , you're making the coil get its power from the battery alone and drain the battery, but try it out and see if its your alternator buggering up our electric system.
try the other way around too, disconnect one of the leads while the car is in idle. This can sometimes tell if the alternator is working good or bad by itself.

A bad batttery can sometimes throw off other components.

i still think you should try to find another ECU and see if thats the issue

 

will try today

 

Just unplug the maf...

Note: The ecu will not let the car rev over 2200 rpm when the maf is unplugged..

 

Not likely,i have never heard of a maxima ecu failure since i have been on this board,with the exception of a heater core leaking on it,causing the failure..

Not saying it's impossible,just unlikely..

 

Huh?

So you're saying the rpm needle jumps up to 4000rpm,but the engine is still at idle?

 

Gents, FIXED it, I tried another ECU and Computer. NO JOY! Went to the junk yard and found another distributor for 10$ and YEAH!!!! Everything works as advertised. It was the Crank Angle zSensorinside the distributor!!! Thanks for all your help GENTS!!