one last try to get maxy running
 

well, taking her in and doing an ects sensor, fuel filter, and possibly a iacv. plus, i bought 2 injector rebuild kits just in case the 2 older ones in the front are leaking, although i can't smell any gas.wish me luck.

My intermittent low idle issue has been resolved. Replaced EGR valve, EGR BPT valve, EGR guide tube, fuel filter, fuel pressure regulator, fuel injectors (Hitachi), ECTS, fuel lines, bypassed the throttle body coolant line, bypassed the intake manifold coolant lines and deleted the cat.

Other than it smellin a bit more from the cat delete she's running great.

Wish you luck with yours!

so, we replaced the iacv with an oem one, the ects sensor, all new plugs and she seemed to be running great. after she ran for awhile, then sat, then i drove her home, she started bucking and stalled once right up the block from the house. i wanted to do the fuel filter, but he didn't, it's either that or a fuel pump. will a failing fuel pump throw a code? no smoke or fuel smell, car ran much smoother but still doesn't seem to want to crank right up every time but it always starts now, just about. seems like after she's been running for awhile and warms up, that's when she will hesitate to start.

Was the fuel pressure regulator ever checked? If not, I believe you can just check the vacuum hose connected to it to see if there is a fuel leak.

Hi, MAXRIDE41, how you doing it's been a longtime since, I have been on here and we have been talking. It sound like their is something always wrong with your car. If it's fixed and running one minute, the next it's bad again. I know your car has been through a lot and you have lots of miles on it. The last time you were talking about your injectors when The wizard and us all were trying help you out. The car it's doing the samething again.

fpr is new, it's not injectors vq. no codes and no gas smell at all. last time i checked, bad or failing injectors don't make an engine run good, and then after warm buck under load. that's why i ask if a failing fuel pump will throw a code, i know a clogged fuel filter can cause similar issues, i'm doing that next chance i get.

After writing this post it struck me that it could also be the Throttle Position Sensor


So you're bucking, but not misfiring? Could be fuel pump, it sounds like something is definitely cutting power. That makes it seem like fuel pump or MAF, but you said the MAF is new (and I'm guessing OEM). Injector issue would almost certainly cause a misfire, I'm not sure about fuel pump but I did run outta gas a few times in highschool when I lived far outta town and it will begin to buck.

First, check for codes, if any and go from their. I do noticed that the fuel can throw codes, if it's really bad. it might lean towards an evap code of some sort. I replaced my fuel level reader because the gauge stopped working and the code it never threw it and i depended on the orange empty gas light. I took the whole level and the fuel pump part so i can replace the leveler. the pump has an harness and so does the leveler so the ecu can control the fuel pump delivery and the gauge cluster would show the readings. i am sure this same harness world let you know if the fuel pump does or should go bad. If you can pm me i can help out.

maf is not new and throwing no codes right now. it seems like after she warms up the engine starts having a shortage of fuel and bucks intermittently until finally stalling. it seems like the faster i go and warmer she gets, the more it bucks and wants to stall.

Have you checked your catalytic converter? Maybe it's clogged up. Throw a test pipe on there see how she does.
Also, take the manifold off and give it a good cleaning (blow by ports, vacuum ports and egr ports)

Ill shoot a couple cans of brake cleaner in there then dry it out.

It' was also noticed that right where the strut towers are the harness wires in the back near the passengers side the harness tends to break and have wiring shortages. The shortages can be minimal or maximum some can throw codes and some won't. Start the car and try wiggling that back area see, if that will make any differences in how the car idles. Check all the hoses and gaskets and the intake box and it's elbow. I had a missfire and a stumbling and rumbling with my car when i took off my intake plenium and i didn't install it right it was rushed. I started the car it was missfiring and i re did the installations and egr what was the problem it was not sealed. I redid everything and now it runs good.

It's your injectors. It is entirely possible for them to run just fine with engine cold, but as engine warms up they seize up. Bad injectors may or MAY NOT cause a misfire (a misfire is far more likely to occur with a bad coil pack.)
This video I watched a few days ago is the EXACT same issue you're having (albeit a totally different car.):


The whole video is almost an hour, you can watch it if you want--but the jist of it is dude had a corvette that would run pretty well when cold but then start to buck and stall the longer it was driven, until it was stall and not start back up.
If you just want to watch the crux of the diagnosis/ problem solve, start at about 23 minute mark and watch for about 10-12 minutes. But it sounds exactly like the issue you are having.

Good luck

Bucking when the engine is under sudden load is often a fuel delivery issue. The car might get enough fuel to run properly under most conditions. But will buck when on a hill or a freeway on ramp.

I've experienced this myself, in other cars. Often times replacing the fuel filter will solve the issue.

that what i'm going to try next, although, it's only maybe 2 years old, i had all these problems after i installed it. cheap enough, crossing my fingers.:noes:

Sounds like a fuel issue... A video would help us a bunch on your issue. Might as well replace the entire fuel system if they're all original and old if you plan to keep this car.

sometimes i just want to slap you.....:slap:

so, she starts better, but still idles kinda weird and a lot less smoke. when i turned the heat on, within a minute she stalled. tps or fuel pump or fuel filter? i was thinking try the filter first, and see if it gets any better. under load she was bucking after warming up and eventually stalled the other night. solid answers please, i've done almost everything to this car, thanks

So already you replaced iacv, ects and new plugs (spark plugs?) what else? If a new fuel filter improves conditions but then it stalls when the heat is on, (heater takes a draw on the electrical system) I wonder if it could be an electrical issue not giving the coil packs enough power. Or the fuel map is cutting more fuel than usual after warm up thus going back to the fuel delivery issue. Does it still bog going uphill without the heater on after warmup?
IDK for sure but I'm interested in the solution as well good luck.

For what it's worth I had an *occasional* bucking issue (in addition to shifting issue and starting issue) and all were fixed with a new TPS.

The MAF sensor is not new, but it can be failing the MAF is supposed to help with the A/F mixture along with the o2 sensors to provide the car with the best performance. The IAT also helps with this matter and it helps the MAF get a better readings. I would try the swapping of a used MAF and a IAT with a used one or a used good conditioned one. The IAT sensor can cause starting and idling issues along with the car wanting to stall. The improper readings of these both sensors will give the descriptions as your describing.

The electrical load from the heater fan causes the engine to stall.

I'm thinking of two possible reasons.

1. A bad ground. Most likely the negative cable and it's terminals. One possible test would be to install a temporary ground between the engine and frame, or directly to the negative terminal.

2. A vaccuum leak. If you have a scanner, look at the fuel trim. It should read near zero. If it shows positive numbers, the ecu is compensating for an air leak somewhere.

Along the train of thought JvG said above.....

A bad EGR valve presents like a vacuum leak as well.

sounds legit, where to find a replacement tps that's oem. i'm not putting aftermarket crap on this car anymore, it doesn't last. link me man, thanks
o, and i'm going to check grounds, probably need cleaning up and re-tightening.

side note, to everybody that responded to this thread, thank you. if you saw the laundry list of parts that i did to this car, you'd be blown away. maybe i'll list them when i get a half an hour, lol

I vaguely recall reading that the BeckArnley TPS was a reboxed OE Nissan unit. I couldn't find the specific post I read that on though. If so, Rock Auto has them for under $50. I did pick one of the said units after reading up on it, and it has been working fine since swapped onto my car awhile back.

Assuming your car is 98 (in case there is a difference in years)...
https://www.rockauto.com/en/catalog/...sor+(tps),5136

Did you ever test the fuel injectors as I mentioned above? You and pretty much everyone else in this thread seem to be immediately dismissing that as the problem even though that's what it is as evidenced by the video link I posted.
Swapping out fuel filter, TPS, MAF sensor and anything else mentioned in this thread will NOT fix the issue.

no, and i'm not going to because they're new. i am going to test fuel trim to see if there's any issues with fuel delivery. people insisting that it's injectors are starting to annoy me, there's no codes or misfires and it's running on all cylinders.

i have a 95 zero, which brand do i use? i wanted oem as stated, maybe i'll get a used oem.

Since OP insists it's not the fuel injectors or signal operating them, I'll second this as the next thing I would check. My only hesitation here is the fact that he says his CEL is not coming on which it should be in the case of a malfunctioning EGR valve-- HOWEVER remember that these 4th gens are notorious for clogged EGR tubes as well, which could be causing similar symptoms to a bad EGR valve but not throw codes or cause the CEL to illuminate.
The EGR tube is easy and free to check so that's the next route I'd take.

feel free to come on out and tear that ***** of a thing out, i replaced the egr tube like 8-9 years ago brand new. not to say there isn't some possible build up but i've seafoamed and cleaned the crap outta the throttle body and the iat sensor is new as well as the fpr also.

While your injectors might be new, they can still
leak, yet not throw a code.

Not saying that the injectors are definitely the problem, but they are still suspect.

I removed my uim when I rebuilt my injectors, cleaned the egr, etc. Only I did not replace my valve covers. So.... I had to remove the uim again last week. That was not fun. But not horrible.

Your mind open to what members are telling you.

Especially the well known ones.

J... Stop hurting your head like that. You're getting a flat spot. LOL:banghead:

Agreed. I've told my story many times on how I installed new/rebuilt/refurbished injectors, only to have the same issue misfiring/white smoke caused in a different cylinder. JoshG recently experienced the same thing as well. JoshG was stubborn too, at first, but ultimately replaced his injectors (again) and solved his problem.

NEVER DISMISS NEW PARTS AS BEING TROUBLE FREE. I'm not saying I'm 100% confident you have an injector issue, but don't be so closed minded Maxride41, and say it can't be the injectors. It very well can be.

KP, Sometimes my desire to be helpful results in flat spots in my head. Generally in the same area as my rather large bald spots.

ill take your hint, and fix some warm popcorn

Don't forget the BUTTA! LOTSof it! LOL

Keep Rockin!

Just to add some input regarding injectors, remanufactured or rebuilt injectors sold on eBay (even oem originals) could be suspect based on the results of the ones i recently purchased and had balanced and blueprinted by RC Injectors. They were far off the mark. i don't recall which injectors the OP went with, so my input may be moot for the situation.

Maxride41, i may have a spare used oem tps you could have it you wanted. I picked up a used throttle body recently and it may still have it attached. I can't guarantee it is functional or even oem though...

If it does turn out to be an injector or more, this is why I prefer doing the front bank FIRST and after they prove to be running perfectly, then put them in the back and the last unused three in the front so if any are bad, it's easy access and then replacement. AND LUBE THE O-RINGS WITH OIL and install gingerly.

If it's the first time injectors have ever been replaced since new, Definitely replace the seating grommets and top insulator cushions as well. AND make sure you have a JIS #2 Philips screwdriver for the screws. (Japanese) This way you won't destroy them removing them. Japanese use a different tip cam style and engage way more intensely.

I'm still thinking too much air getting in somewhere. If it's not running, can't trip any codes to validate that.

starts right up first turn of the key, little smoke, then warm her up and she runs fine. i don't have the money to tear these rears out, and my mechanic is positive it's not an injector issue, yet he can't figure out what is causing the issue so, i even bought a couple of rebuild kits for the front injectors, but the car was running much better after we did repairs last week so we didn't check them. i'm not saying there isn't a chance in snowballs hell that it couldn't be maybe one or two injectors, but it seems more like an electrical problem than gas at this juncture. you get to know your car like i know my ride and what you've done and it becomes apparent that certain things just fail on your 24+ y/o maxy.

also, i found this on rock auto ,https://www.rockauto.com/en/moreinfo...1211386&jsn=11 its a ntk tps, is it reliable?

NTK = NGK (as in the ad.

I would buy that.

cool, i thought so.

I am not ruling out the injectors due to the white smoke out the tail pipe. I am sure that this is related to fuel that's dumping out. I am curious on the head gasket yes, the head gasket has similar signs of white smoke coming out the tail pipe with hesitations and some bucking. I had my Chrysler that had just started the head gasket issue and the white smoke was also showing with misfiring with hesitation and with slight bucking. I was also loosing coolant on the poor thing. I am sure that the problem you have it's possible that it's injectors that are either with bad pintle caps or you have a bad o-ring seals and the seals are bad. The thing that bothers me that you are having all of these problems without any codes.