lionheart320

Hey guys, I have a 92 auto se. My car has just recently started severely bucking and almost stalling while traveling at highway and city speeds. Im an insurance adjuster and travel for long distances and I noticed my car will only do this in hot climate. For instance, yesterday i was in shreavport,LA driving after about 3 hours in hot weather when my car started bucking really bad. If I left the trottle at the same position the rpms would jump up and down like the car was about to die. So this went on for about 5 minutes until i pulled over. I started it back up after 10 minutes and it ran fine momentarily. However, when the temp. outside dropped at dusk, my car was pulling real hard and driving like it should. I drove all the way to tulsa, ok without any problems whatsoever. It only does it during hot temps.; and ive noticed this after multiple long trips. My o2 sensor is brand new. Any suggestions??? Could it be the mass air flow sensor, if so would this explain it only bucking in the hot weather like its messing up the air/fuel ratio??? Thanks for your replies.

Wiking

Yes it could. But there are also multiple other possibilities acting only when hot.

Why did u change O2? The new one may be faulty...

Coilpacks? Plugs?

Check charge voltage level.

Oxidized connectors act while driving: resistance increases when hot. If never done, harness PM is necessary. Also add extra gnd wires.
click: http://www.cardomain.com/ride/748507/14

Cliff Clavin

iTrader: (11)

there are lots of possibilities, but bucking is often caused by coil packs. Does your bucking usually occur when you step on the gas? This is what happened to mine a while back.

Take out each coil pack and check for cracks. This is a clear indication of one needing to be replaced. However, the rear ones will go bad and look brand new. They have to be tested for resistance. On mine, the passenger side rear one was bad and it caused my problems.

Coil packs are not cheap --about $60 each from a parts store and about $100 or so from the dealership.

Other possibilities are an injector going, the cam position sensor, throttle position sensor, mass air flow sensor or a host of connections. It seems like most of the problems related to bucking/stalling are electronically related, but it could also be a fuel problem. Fuel filter, fuel pump, etc.

bhunter

iTrader: (3)

One of my cars did this same thing and it was the coil packs also.

lionheart320

I changed the o2 sensor after the problem started in an attempt to fix the problem. However it wasnt the problem. I read a write up under maxima troubles about this and everything red92maxse experienced is what mine is doing. I understand that it can be different sensors but i just dont want to install parts on a hit or miss basis. But based on a couple of different members' cars symptoms im leaning on just changing out the coil packs.

Wiking

Plain swapPing: Tell me, what else there is to be done with an intermittent fault? List the choices, start with the easiest/cheapest. This is what you did, cont...

In this case the highest peaking heat fluctuation points may be mapped: coilpacks are on top of that list; full of electronics. (take a couple of thermometers and place their sensors under the hood to check out)

Still I'd swap plug$ before coilpacks, I'd try one notch cooler set.

subs1000w

+elevintybillion on the coil packs thats what was causing my problems and a friends which sounds identicle to yours and everyone elses

if you cant go to the junkyard and get some for cheap i would suggest buying 3 at a time first do the fronts (they seem to be bad moreoften) and if its still there do the backs

also all mine read fine on a meter but it was still the problem

CandiMan

iTrader: (1)

Someone in another forum posted a similar problem like yours.

He states:
"My daughters 92 se is acting up, runs great, then while driving car stumbles then quits, car has 220k on it, no maintainence done recently, was wondering what to look for(I have a 1990 TTZ), so I`m familiar with Nissans in general, but I have never had this kind of trouble with the Z any help appreciated"


This was my reply and opinion from that forum. I'll just copy/paste:
"Our Maxima's have to known to have several driveability problems, from stalling, jerking, stumbling, hesitating, low power, etc. In my opinion I don't think anyone have that one true fix that will solve any one of those problems.
A lot of those problems can be attributed to faulty sensors but more common are faulty connections. Since you're firmiliar with Nissan's start with pulling the codes, if that doesn't lead you to anything start checking/testing sensors and connections. The knock sensors, coolant temp sensor, and TPS are several sensors that routinely go bad. Also check the harness connection for each one of those (or any other) sensor.

Since your daughter have the DOHC motor you might want to check each igniton coils. They have been known to have external crack which will cause the spark to arch to the head instead of going to the plugs. If they are crack and shows signs of arching, simply wraping the coil with black electrical tape have been known to correct the problem. I can attest to that.

I've had my Max since 96 with 29K on the odometer and 9yrs later I now have 153K miles. Besides two months ago when I have having a starting problem (it would crank but not start) the engine have never stall on me and have always started for me. Sure I've had my share of driveability problems, like hesitating, bucking and jerking. "My" hesitating was due to crack ignition coils, I tape the coils, problem solved. "My" bucking and jerking was due to a faulty TPS, changed the TPS with a used TPS problem solved.

The starting problem I was having two months ago was due to a faulty coolant temp sensor and/or harness. Who would have thought a CTS can caused the engine not to start. I've seen fautly CTS cause a engine to run like crap when cold or hot, but not cause a starting problem. Regardless, I changed the CTS and harness, problem solved.

During the past 9yrs of ownership I've probably wash the engine 3 times and I have the pics to prove it. So if you're into washing the engine bay on a regular basis that will contribute to faulty corroded connections.

In "my" opinion it pretty much comes down to doing a thorough checking of sensors and sensor connections. I don't think there's that one solution that will fix your problems. I don't know what's the plan for your daughter car, but if you're planning on keeping it for several years I would invest in a Factory Service Manual (FSM) It gives you a lot more info than what your average DIY's will ever need but more info will never be a bad thing.

I'm at work right now and I work the graveyard shift. I can go on and on so I'll stop for know.

Good luck
MIKE

PS: Once again I'm currently at work when I posted this reply. I tend to do a lot of my web searching while at work, so there goes my productivety for 8hrs

Wiking

Some Comments to Mikey:

- never use water in computer rooms. never. still, keep it clean, especially connectors.
- crunched, pinched, shorted, cutoff, five or ten - series/parallel: temp sensor is never a starting problem. no way u may prove that, Mike.
- invest to a computer and do some clicking - to find that FSM.

CandiMan

iTrader: (1)

-If you're calling the engine bay the computer room, I agree it's not a good idea to constantly use water. As stated I have pics to proved I hardly ever wash my engine.
-You state a coolant temp sensor could never cause a starting problem. Prior to my engine not starting a few months ago I would have agreed with you, but I know what I did to resolve my no start problem which was replace the coolant temp sensor.

Viking, you are always refering others back to the FSM so let me ask you this. You know it takes three factors for a internal combustion egine to run, fuel, heat and spark. Take away or alter anyone of those three factors and you can have a driveability problem.

Looking at the FSM there are several signals/sensors the ECM uses in order to determine the injector pulse width. One of the sensors the ECM looks at to determine pulth width is the coolant temp sensor. In my case could it have been possible that the ECM was getting incorrect signals from my coolant temp sensor which in turn was dumping either too little or too much fuel creating a not start problem?

MIKE

Cliff Clavin

iTrader: (11)

mine was having a non-start problem and it was the coolant temp sensor. The engine acted as if it were "flooded" like an old carb.

When I checked the codes on the ECU = code 13 (coolant temp sensor)

Coolant temp sensor = $20 at NAPA and about 5 minutes to replace on a VE

Wiking

Computer room reference: http://www.cardomain.com/ride/748507/14

As far as FSM informs, the 1. temp sensor (variable resistor) is used to open/closed loop ECU control. Closed loop is when feedback from exhaust via O2 sensor is possible (engine warmed up). This is done based on coolant sensor resistance.

Temp 2. sensor is used for EGR.: http://www.cardomain.com/ride/748507/3

If this signal is missing, ECU uses never closed loop (O2) and relies only to TPS info and uses preprogrammed table to guess injection based on TB info.

I am not denying that your car started after temp sensor swap. But max being fully computer controlled, microsoft stock drop could have the same effect...

Do the empirical test: install your faulty sensor back into the temp wire and test. Ground it... no need to install into block. If your car does NOT start, I am baffled.

CandiMan

iTrader: (1)

For shiits and giggles I would try your test, but I already discard the old temp sensor and I also replace the coolant temp harness along with the sensor. Besides RedMax recent input I never heard of any other Max having a starting problem that was due to a coolant temp sensor, I don't frequent the board as I use to.

Wiking

Then the problem source cannot be verified.

Any time computers are repaired, the suspected parts have to be verified (systems under yearly maint agreement) multiple times. Otherwise parts consumption shoots outta roof... Car repair industry is the opposite: Stealerships are masters in this milking; cu$tomers pay whatever is done. Even parts that have NOT been swapped.

How do u know computer tech is changin a flat tire? He tests the flat on each axle end - just to make sure he has pinpointed the cause...

Nobody can show a max that does not start if temp resistor bad. To claim that means repeatability - not a once in a lifetime experience: any time you put that bad resistor in place, engine is dead.

This is cause the ECU temp input takes in only a value 1 or 0, and this comes in form of voltage level depending on the resistance. And whatever there happens to be in that input, that defines ONLY open/closed loop function. Open/closed loop -feature has 'nothin' to do with starting.

If you want, you may tst with different resistors [I currently have a 2.2k bypass] in place of the temp sensor and try to simulate. There is no way you can find a resistor that can kill the engine. Sorry.

CandiMan

iTrader: (1)

I understand your vast knowledge when it comes to automotive repairs, but I also consider myself very knowledgable when it comes to auto repairs. I may not be up to par when it comes to these newer electronic gizmos that the import tuning industry is using (e-manage, SAFC, etc.) but when it comes to basic auto repairs (electrical, susp, engine repair, brakes, etc) I can hold my own.

With your knowledge of the industry would you agree or dis-agree that sometimes shiit happens that doesn't make sense. Can you honestly say all the diagnosing you've done have always lead you down the correct "normal" path? There has never been a time when you said to yourself "damn that's weird, that has never happen before" If you can say all of this has never happen to you, you my friend are definately one of the elites in the industry and I applaud you.

You state the coolant temp sensor is a variable resister that sends a voltage back to the ECM depending on coolant temp. This statement I totally agree with you, but is it possible that the signal going back to the ECM could be incorrect in the way that it causes the injector to pulse too much or too little fuel which in turn causes a hard or a no start situation? Is it possible the signal going back to the ECM from the coolant temp sensor is telling the ECM to dump a lot of fuel because it detects the coolant is cold but in reality the coolant temp is at operating temp? It's basic automotive knowledge, what happens when you try to start a hot engine with the choke on?

With your statement that old suspected parts should be re-install to varify that's the cause of the problem, that sounds exactly what the text books says to do but in reality who really puts back a supected part to varify that was the cause. Working in the industry for a living you don't have time to re-install that old part to varify that was the problem. I don't even think a average DIY's in his home garage would re-install a suspected part to varify the problem. We diagnose, change a bad component, if that solves the problem we're happy, discard the old part then move on.

I understand your opinion when it comes to a component causing a specific problem it should show some sort of repeatability in the industry and not a once in a life time experience. But I do understand when it comes to mechanical and electrical stuff everything is not always written in stone, and sometimes you have to have a open mind a realize that shiit can and will happen. Before this starting problem happen to me, personally I would have probably been like you stating there's no way a temp sensor could have caused a hard stariting situation. Someone else in this thread stated he had a starting problem, changed his coolant temp, problem solved and he moved on.

At this point we're totally going off track to what the original post was all about. I stated someone in another forum had a similar problem so I decided to copy my reply from that forum and paste here. You read my reply and choose to pick out one situation from my post which was irrelevant to the original post here. Pretty much what I was trying to say is that no one has that one true fix that will solve his problem, it could be a combination of many things.

At the risk of taking this thread more and more off topic to the orignal post, I'm more than willing to continue discussing this situation which I'm sure you will do. At the end of all this please don't get me wrong, I do understand and repsect your automotive knowledge but at the same time I do understand that sometimes stuff happens out of the norm.

Tag you're it
MIKE

Wiking

Dont make me the issue: I can make REAL bad mistakes, thats beside the point.

Just prove yourself you can 'stop the engine' via temp sensor. You cannot. Sorry about that, no way.

Btw. Max does not have a device called choke.

CandiMan

iTrader: (1)

True or false, there are many sensors and switches that the ECM looks at in order to determine how much fuel the injecters will deliver.
-If you answer false, stop right here, no need to read any further
-If you answer true, then proceed.

True or false, the ECM looks at camshaft position sensor, MAFS, CTS, O2 sensor, closed throttle position switch, inhibitor switch, vehicle speed sensor, ignition switch and battery voltage in order to determine how much fuel to deliver.
-If you answer false, stop right here, no need to read any further
-If you answer true then proceed.

True or false (and this is the kicker) if anyone of the above sensor or switches malfuctions it can effect fuel deliver, which in turn can effect driveabilty, which in turn can effect starting.
-If you answer false, more than likely we will continue our debate
-If you answer true then hopefully you see my point

BTW, if you don't mind me asking how old are you? For you to make a statement the Max doesn't have a device called a choke then you appearantly don't know what a choke is. Of course the Max doesn't have a choke. A choke hasn't been around since the 60-70's but any knowledgeable mechanic would know what a choke was and how a malfunctioning choke system can cause havic when trying to start a engine.

Mike

CandiMan

iTrader: (1)

That's the difference, even though I find it hard to believe chokes were still being used in the 90's I have no proof to prove other wise so I'm willing to accept that as being possible true.

EDIT: I have to continue this conversation next time I log on, gotta go

subs1000w

accually i can support to CTS no start heres how

a long time ago i tryed bypassing the CTS with a resister of some value not sure anymore to tick the ecu to thinking the car was cold all the time to see if it would fix the infamous heat soak well the car did start and run like this for about 5 days but it seemed to be progressivly taking longer and longer to start and finally on the 5th morning i went out to start it and it woudlnt start just crank cranks crank

my ECU didnt throw any codes but the fuel pump wasnt coming on so i blamed it and order a 255lph and that came a week later and i put it in and it still wouldnt start so i just figured id try removing the resister and try it again and wala it started first crank

i cant explain why or how this happened but i bet if i put a resister in it would do it again on any VE

sombody try it i would but my car dont run right now just look up in the FSM what resistance the CTS reads at 100degreees get a resister of that value and put er in then report back in a few days with your findings

Cliff Clavin

iTrader: (11)

It was definitely the coolant temp sensor on my car that made it not want to start.

I even had a video posted (I since deleted it from my hosting place). Car acted like it was an old carb that was flooded. Was very hard to start and then wouldn't start. Cranked and cranked, but never started or just coughed a little bit.

Seems pretty straightforward to me -- it even threw the proper code.

When I replaced the CTS, it fired right up. Like I said, it was $20 and took <5 minutes to do. One electrical plug and a 19mm deep socket, IIRC.

CandiMan

iTrader: (1)

Honestly at this point it really doesn't matter. Some might believe a CTS can cause such a problem, while others might not believe, it's no big deal. Hopefully lionheart320 has made some progress with his bucking, stalling problem.

MIKE

Cliff Clavin

iTrader: (11)

I saw that he bought some coil packs. That cured my bucking and stalling problems.