Greetings,

I need help

I have a 1991 maxima - for some reason it developed a major miss in it (or at least it seems so) it sounds like it's not running on all cylinders. Furthermore - problem seems to be intermittant - lately it has been too frequent.

I just changed all plugs, distributor cap and rotor, wires (all dealer parts).

This problem seems to be more noticeble and present at lower RPM's.

I was thinking O2 sensor - but it's not chugging any black smoke or anything - and it was changed about 1 year ago. When the car doesn't have this problem - it run's great (like new). But when this problem shows it's face - it's a different story.

Could there be any other sensors that may cause this problem - how can i go about trying to solve this ASAP?

I was thinking maybe injectors??

another problem i have whick i hope to get in garage and tackle today is...the thermostat seems to be gone (intermittant heat) and sometimes i find a little bit of coolant on garage floor (but not always) i cannot find any leaks!!!!

Could there be anything related in these problems - is there something i'm missing??

Please HELP!!!

Thanks in advance

Rob

 

i thought that u meant someone stole your car when the post said..max missing

 

How about checking first if by chance you cracked the ceramic housing of all of your spark plugs. If those are good, ensure all of your wires are hooked up tightly to ensure a good connection.

As far as a bod thermostat causing these problems, I doubt it. But change it out if you believe it is going bad.

 

Does the car vibrate alot at low RPM's? If so then it could be the injectors. Check the injectors by using a stethascope or a simple long screwdriver and touch one end to the injector and the other end to ur ear. I would recommend the handle end to the ear. Anyways, listen for a strong ticking sound from each injector. Be careful not to mistaken the ticking of the near by injectors. If there is a strong ticking sound from the injector then it's good. if not then time to replace it.
A definite way to make sure is to take each spark plug out while the engine is running and see if the RPM drops a bit. If so then the specific cylinder is running fine. Do this to each engine and also consider doing a compression on each cyllinder. I had an injector go on my car so it was running on 5 cylinders. Sounds like the same symptons that u have. Good luck!

 

Are the injectors something i can change myself? That is something i have never attempted...

Is there a place to buy injectors for a 1991 maxima at very good prices??

The main thing i don't know about injectors - are the injectors parts that you just put in and they are preset from the factory??? - or do you have to adjust them??

Thanks,

Rob

 

Changing the injectors aren't that hard. Just need to take off the intake plenum and the intake collector. The Chilton manual will give you a good description of this job. U'll need a hex head bit(can't remember the size), a 3/8" drive rachet, and a torque wrench.
As for the injectors them selves, u could go to the junk yard and get all 6 for $35 including the fuel rail(at least that's the price I got at my local junk yard) or u can go to the dealer and pay $113 for one injector(they quoted me on that one). I talked to the techs and they said they usually replace only one of anyways instead of all of them.
It all depends on how long u'll keep the car and how much cash u have. I'm a college student and I got mine from the junk yard instead. Oh, while ur at it think about cleaning the intake plenum and a port and polish. Trust me it will be worth ur while. Good luck!

 

Rob,
Before you spend money (they are not cheap) please have them checked out to insure you are fixing the problem. It would be a waste of money and time if you are just guessing and hoping that this will fix the problem. I,m unsure sure of 3rd gen but on the 4th, replacing them would be labor intensive. Listening for operation is one way to check them. Using a volt/ohm meter is another. Achilton or haynes manual should have the correct specs. Hope this helps out.

 

I've been having the same problem, exactly. I tuned it up about four months ago then dumped cleaner in and things cleared up. Started running rough again, same as you decribed. Place I took mine said I had one not firing at all, 3 not working properly. Suggested changing all, with a little something here and there coming out to the tune of $1,500! Looking for a shade tree mechanic.