u-turn

Hi im new to the maxima scene and need some help.
I was recently given an 86 maxima that doesn't run
very well.It doesn't want to idle,sputters when you
take off and the exaust smells very rich but runs
great once its moving.I'm wondering if theres any
way for me to pull codes at home or what could be the cause.I've also purchased a coolant temp sensor but can't find anything that resembles it anywhere on the engine. Please help

maximase86

iTrader: (24)

Alright, to pull the codes off the ecu, here is the procedure on doing that, this was provided by alllw86:

The ECU self-diagnosis for an 86 are different from the +87 cars.
There are no additional modes to get into.

There's nothing wrong with your ECU giving you the code 23/31, you
didn't completed the full procedure correctly so those codes came up.

To do the self test on the 86 and probably 85 maxima, do the
following:

Verify mode selector is turned fully CCW
Turn ignition switch to "on" position
Inspection lamps will stay "on" (bulb check)
Turn mode switch fully CW
Depress accelerator pedal, then release
Start engine,
Apply brakes and shift to "D" position...nothing said for SE 5sp
Turn one of the load switches....OFF....ON....OFF...
Code #31 will be erased after the E.C.C.S. control unit detects one
of the load signals below....

Power Steering oil pressure SW
Air conditioner/Heater SW
Headlamp SW
Rear defogger SW
Radiator fan SW

Shift to "P" position....again nothing said for SE 5sp

Make sure that inspection lamps on control unit are displaying code
#44....no fault code

Also, there are a two coolant temperature sensors, and they are both on the radiator, both are on opposite corners. You can see one of them on the passenger side of the radiator, near the top of the radiator. There is also a cylinder head temperature sensor. I forgot the exact whereabouts are, but I think it may be need the thermostat. You might want to check a Chilton, Haynes, or Factory Service Manual for location.

S

maxi-freak

You're correct. The cylinder head temperature sensor is next to the thermostat. It's really kind of a pain to get to. I wouldn't change it unless it's really bad. Before you assume that it's bad, break out the ohmeter and check the resistance range of it (it's a thermistor that varies resistance with temperature). You can even emulate a cold or hot condition by inserting the proper value resistor into the connector.

maximase86

iTrader: (24)

Also, if your CHTS is bad, you'll probably be getting a code from the ECU, because its used to help figure the air/fuel ratio. Check that first. If you don't get a code, then crack open the tester to see if it still alright.

S

u-turn

Couldnot get codes probly cause the engine wont stay running long enough. Do you know what resistor is used to emulate a hot condition.I will highly appreciate the info and will be trying the code check again.

u-turn

HI again. Well ive adjusted the idle linkage enough to keep it running but still cannot get any codes. Ive followed the steps above but dont see anything on the control pannel flash.what will flash? I found the cts by the thermostat whos idea was that!that would take forever just to get to remove it.And i hope this dont sound stupid but what is the CHTS and where? Thanks for all the help sofar.

MaxWgn

iTrader: (1)

The CHTS is the temp sensor you found next to the thermostat. It stands for Cylinder Head Temperature Sensor.

u-turn

ok ive retrived codes 12,13,23,31. i understand that the 23 and 31 are ok but what about the 13 and 12.i dont have a manual yet to decifer the codes.thanks again for the help.

IROC Z

well I dont know the codes on this particular yr but I do have some good tips. pull some plugs at random and check them for gap/wear and condition, could be oily whatnot. this is really good info. 2nd thing is you will more likely then not need an O2 and I wouldn't doubt if 1 of the codes is a bad O2. running noticably rich and stumbling can often be an O2 or a sign of a bad O2.

I would try pulling the negative termanil off, replace the O2, give it a test drive and re-check for codes.

maximase86

iTrader: (24)

Alright if you follow the procedure right, when you depress the throttle once, and start the car, error codes 23 and 31 will go away. Part of the process. Here is the info for you other codes:

Code 12 is the MAF sensor. It could be shorted, circuit is open, or the MAF sensor is toast. You should check your airbox for water, AIV tends to spit water out when it goes bad, and destroys the MAF sensor. You may have to go the the junkyard for one of these, since they are expensive new.

Code 13 CHTS, it maybe shorted, circuit is open or CHTS is bad.

What you need to do is replace those components. Then run the ECU test again so it can clear those error codes...though this run will clear those codes, they will come back because those components are bad. After that I would double check your timing, and reset your idle.

S

IROC Z

nothing personal but i would pull the terminal to reset the ecu, restart, test drive and re-check the codes. Maf sensors arent cheap.

maximase86

iTrader: (24)

Well, with the current symptoms he's having, rough idle, engine running rich, there is no doubt the MAF sensor is bad. What I would do is call around to a few junkyards first. Its too expensive new. I think somewhere in the neighborhood of $100 plus dollars. Either way you can try that to make absolutely sure of course, but I can tell you there is no doubt that its a goner. :

S

u-turn

Thanks yall I replaced the CHTS and reset the computer test drove what seemed like a different car rechecked the codes and now am only comeing up with the 23 and 31. It still has a small stutter but i think some fresh plugs will clean that up. By the way what plugs do yall see the best results with.

maximase86

iTrader: (24)

Wow...did I get proven wrong.....again? LOL. As for the studder, a set of plugs, maybe a new cap, rotor, and some wires will probably do the trick. You might want to check the timing while your at it.

S

IROC Z

remember if you cannot pop a code at least twice then it maybe a short or fluke. I always reset the ecu/ecm and recheck for codes rather then buy a part I may not absolutely need.

as has been said cap/rotor/wires may help but more likely its several small things in combination that are causing problems, giving you a stutter or stumble feel. A new O2 is still a really good idea, check the exhuast again of course for richness but a new O2 can improve mpg's and smooth out a rough car. of course basic maintenance issues like fuel filter, air filter will help as well.

When I picked up my 84 the air filter was clogged, the thermostat was stuck and the O2 was bad along with 1 fuel injector. I replaced all of those along with the oil and improved my mpg 40%.