So my maxima's idle sometimes bounces around 50rpm or so fairly fast. Like up and down 2-3 times per second. From 650to 600rpm. You can even hear the engine noise alternating so I know the gauge is working. I have a 97 SE. The video link is basically what's going on...not my video tho..


Anyone know what's up with this? I've replaced the coilpacks and MAF. Also tested the TPS and IACV with a multimeter.

 

Well, after buying new oem coils, ngk copper plugs, new ebay maf, swapping iacv and tps and using remanned injectors I've chalked this issue towards cylinder compression difference. I went about diagnostics in the wrong order partially due to reading what people said on this forum. I hooked up a vacuum gauge to the manifold and also saw very minute fluctuations in the needle which were similar to the tachometers needles oscillation. Although, even if I did the vacuum readings the injectors and coils/plugs would still be in the equation as they're cylinder specific...of course I electronically tested the injectors and coils and proved to be good I guess there's always that uncertainty...somehow. What I find interesting is the fluctuations are random, where you'd think it'd be constant. Well, the engine does have 207k miles....I'm still open to ideas..don't really feel like doing a compression test.

 

well, one cylinder had 178 and another had 190...as accurate as my gauge is, lol...

14 psi is the limit...12 is close..dunno.

 

Ok everyone...I am deducing this issue to the problem being the ECU...even though I replaced it already for an A/C issue. Guess the ECUs have some serious issues when they age.

 

How can no one else know what is going on...like this isn't a common issue or even close or something?

 

Just keep throwing parts at it; you'll get it.
:

 

ya for real...anyhow, good thing my friend has the same exact car so I'm going to try his ecu...

 

my car is doing this exact same thing, no joke. lol.. no one replies on it though.

They say its normal due to weather changing right now..cold weather from December now its changing to spring... so i dont know. I was just in a 2009 car model and it was doing the same thing sort of...so

>.>

and also all the answers are on the youtube video u have posted, most of them.

looks like the car needs some cleaning in throttle bodys, mass air flow...Etc. If the car doesn't have air going through freely, it will get a little clogged up and cause the car not to breathe. its like human bodys... if anything is clogged up in our systems, we have trouble breathing, if we have open air flow in our systems, we tend to do better. Same thing applies to cars.

its not major, but can be later on when ur car stalls on stop lights. better to clean them out now to prevent that. really easy job, any mechanic could do it.

Take off part...Clean it up, spray correctly, install back into car, Test and see if that solved the problem.

 

Post a pic of your negative cable from battery to engine block, close up of engine block ground location please.

Look what I found:
Quote:
Originally Posted by CMax03 View Post
Check your Water temperture sensor it will prolong a cold start and run fine with a slight hunting effect at idle..... Be sure the 5v signal is making it to the sensor and the return wire has continuity to the ecu....

That's kind of what you described happening. Go do that.

 

ahh, interesting. I did change the clutch...and honestly I wasn't sure if I put the cables back on the right spot...is that what you're interested in? Or corrosion/dirt?

the ect has continuity..

 

Supposedly when u remove the transmission for what ever reason the mating surfaces of the engine and tranny must be cleaned immaculately to ensure a good ground connection, if it wasnt done right then you would need a grounding kit

 

It looks like I mounted it to the bottom of the cylinder head.. Part of the cable looks pretty green...I guess I'll take the bracket off and do some cleaning.

hmm, doesn't look too bad actually...

 

man..it's gotta be the ecu

 

I have a 97 Maxima with 115K on it. Recently the tachometer's hands would point to the gauge end, that means the rpm is over 8000. On Freeway, sometimes it would come back to normal about 2000 at 60 miles/hour. I was told to check the crankshaft position sensor that reads the rpm. Is it right? On 1997 Maxima, the crankshaft position sensor has two parts. I looked at the one wired (one thread) sensor, it was soaked with oil. and I cleaned it. It worked less than a day but the problem comes back again. Is it really the sensor problem? I want to make sure before I order the parts.
Thanks for you advise.

 

Scan for codes.

The V.S.S. on top of the transmission is responsible for your speed, but it could be your cluster going haywire.

The FSM in my sig below will offer a lot of useful information on troubleshooting.

Welcome to the org!