RockHillMike

Hopefully someone here can help me troubleshoot this problem. I had to replace my knock sensor on my 99 maxima. I removed the UIM and LIM and everything else to do so. Replace the KS and put everything back together. When I start the car, it idles at over 3000 rpm and actually increases to 4000 rpm. I dont know what I could have done to affect this. Any help would be appreciated.

Violator

make sure all vacuum hoses are connected and everything is plugged in and also on the iacv there is an idle adjustment ****

RockHillMike

I swear they are all connected. Not even sure where to look. Also, what does the IACV adjustment **** look like. Is it the screw with red paint on it or is balck, kind of plastic looking?

jholley

iTrader: (13)

+1

Idling at 4000rpm no doubt it's a vacuum leak after reinstalling the air intake setup.

With the engine running spray carb cleaner around the gaskets and hoses you reinstalled. If the engine hesitates whiling spraying a section then you found your leak.

RockHillMike

I had to get a new hose that ran from my crank case into the LIM I think, it is on the left side of the crank case. I started it back up and it was idling much lower about 1200. I tried to drive to work today and it was idling very high, the car was basically accelerating itself and I could barely stop it at red lights. I wish I had a diagram of where all these lines were.

PH98I30

A surging idle is almost always a vacuum leak. They are hard to locate sometimes. If you have a friend with a vapor cigarette setup, blow vapor smoke into the throttle body and watch for any coming out in the engine bay. It can locate a small leak easily.

Violator

are you talking about the 1/2inch hose that connects the front valve cover to the rear valve cover under the uim? Mine was dried out and broke when i removed it. 1200 actually sounds about right if you just started the car up, when warm it should lower to around 800. Also check out your throttle body cables that sounds like it might be related to your acceleration issues.

I just had my UIM off and used google images to find a good high res pic on a 99 cali spec from above the engine bay to use as a guide for getting everything back in it's spot

RockHillMike

I called a local maxima dealer and asked for some advice. The guy said, from my description, to check my throttle cables. And lo and behold, I had taken them off the wrong way (loosened the bolts) and it was too taught. I made an adjustment and now it is fine. (whew!). but, I did have a coolant leak as that PIA coolant line that is on the back of the UIM against the firewall, which is at a severe bend, was not all the way on. I had NTB run a a coolant system pressure check and found the issue and tightened the line. Only cost $33. worth it! I really appreciate everyone's input on my problem. My next project is suspension. My 1999 Maxima with 223K miles needs all-around coils/struts. I am getting quotes around $1200-$1400. Way too high. Hell I can order the parts at Rockauto for $300-$400. Has anyone installed there own suspension? How difficult would it be for a novice?

Violator

Do what I just did and get a set of tein advance coilovers for the 2003 maximas ($685 shipped). All you have to do is enlarge the top bolt hole for the steering knuckle and they fit perfectly, there are guides on how to change the struts on these cars and the coilovers come with a guide on what order the parts go on and what you will need from the stock setup (borrow spring compressors from auto store to get the reused parts off the stock setup) and also might want to get a torque wrench from somewhere like harbor freight i think i got mine for 20bucks, you might be able to do it without but just to be safe and the guides mentioned using one. I just did this im 19 and a noob.

the tein advance coilovers are very good quality both longevity and ride quality, fully adjustable and easy to adjust, and the ones for the 2003s are more widely available and $300 cheaper than the basic teins made for these cars when all you need to do is enlarge the bolt hole on the front two struts because the bolt is just slightly lower

jholley

iTrader: (13)

A Moderator had the same high idling issue 3 years ago and it turned out to be the throttle cable. Read the last post in this thread

https://maxima.org/forums/4th-genera...-when-hot.html

Sorry I couldn't recall that issue.

Violator

i was kinda thinking that 3-4k rpm sounded high even for a vacuum leak, but after i just did my uim i figured that's what he did wrong bc there's a lot of small things and its easy to miss a hose somewhere