ZXGrinch

I have a question so that I may be guided in the right direction...
82 ZX non Turbo. Stick Shift
When I floor it, around 3500-4500 RPMs, any gear, the z does real small hesitations or hiccups if you will...if they were bigger I would call it sputtering...but the passenger usually wont even notice them...is how small they are. Engine idles great and does not do this when in neutral...only when in gear.

If I ease the throttle up to the same RPMs then it is smooth, only happens when I am getting on it hard.

Ran a tank with fuel inj cleaner last week, and that made no difference at all. Has new plugs/wires/dist/coil.

Any thoughts?

BlueKitsune

Might want to make sure the TPS is working correctly and is adjust correctly. Other then that I'm not sure.

ZXGrinch

I have no idea what the acronym TPS is for...
Sorry...not real great with TLA's yet.
(Three Letter Acronym)
im a tech geek...sorry.

audiofreak97

Throttle Position Sensor...


How are the spark plugs and wires? Is there any play/wobble in the distributor?

You may also want to pull that plastic cover off of the AFM (air flow meter) and see if you are getting a good sweep on the carbon track. See: http://www.kamikazeracing.org/dl/JsAFMRebuild/

Another thing to check would be fuel pressure...

rogerz

get the fuel pressure. check the ignition timing. check the vacuum. lots of s130 problems can be traced to vacuum leaks. dead spot in the afm rheostat another possibility. don't forget to load test battery and be sure your cables are free of corrosion and tight. z's in general don't like low voltage and you get lots of gremlins when the electronics aren't getting full volts. ground cable should ground to the frame and then to the starter. grounding thru the starter is not a reliable connection and poor grounds also cause electrical problems.

ZXGrinch

I plan to put a cold air intake in her anyhow, so checking the AFM will be my first attack.

Thank you for the advice guys.

ZXGrinch

Working on it today....wish me luck.

Doesn't look to bad even though it has been tampered with in the past.
Had the grooves just like it said.

ZXGrinch

That did the trick!
She is running beautiful...no hiccups!
Thank you so much guys!

ZXGrinch

I know this will seem like a silly question but I just can't find the answer searching through the posts...

82 280ZX fuel inj. non-turbo...
When I am driving and the rpm's run a bit low the engine makes a gurggling type sound...sounds like a deisel engine for a second until the rpm's get above 2500.

What is this called...and why does it happen...and how do I fix it?

thanks guys

NismoPick

Merged w/ previous thread.....

Since we can't hear what you hear, we have no idea. Can you make a video clip? Otherwise I'd say aliens have invaded your car. Then it's time to get MIB.

ZXGrinch

" Since we can't hear what you hear, we have no idea. Can you make a video clip? Otherwise I'd say aliens have invaded your car. Then it's time to get MIB. "

Sorry...I will look for a clip of what a diesel engine sounds like.
I figured that was a pretty good description that people had heard in the past.
I must be the only one who has my windows down at redlights to know what diesel engins sound like...I only say this since you stated "we" answering for everyone else

Maybe...someone else will know that sound. I sure hope so.

NismoPick

If your gasoline engine sounds like a diesel engine, you have major problems...

Is that a better answer?

I thought you were EXAGGERATING because 5 minutes before you posted about a diesel sound, you said:

ZXGrinch

If you have ever ran a car when it starts to overheat, it makes a gurgling sound which sounds similar to a diesel...some have told me that is from bad gas in the past, but i have been through three tanks and it is still doing it.

The car is running great...just making a wierd sound when stepping on it in low rpm's.

snwbrderphat540

Is it by chance lifter tick? lol. Cause these motors are straight sixes single cam engines, which is what a diesel engine is other than the fact one is a diesel lol. But the most prominent sound other than a turbo from a diesel is a the tick/knock they make. Which could be described as a gurgle I suppose, which sounds very similar sometimes to the lifter/injector tick of our cars.

J-cubZ

Also is this cruising or accelerating? From what I've been told you shouldn't be crusing steady below 2500rpms anyways if that is indeed the case.

ZXGrinch

I am pretty sure that is not it...I do recognize the lifter tick...the gurggling is louder... BTW how do you quiet the lifter tick?

Either way, but most obvious in first and second gear.
If I shift to 5th to soon it will make the sound up until 2500

Could it be 'ping' i hear that term all the time and I really am not sure what that sounds like?

SHADY280

whats your timing set to? check that and get back. adjust it to about 10 deg. not 8 like the book says

snwbrderphat540

"ping" is pre-ignition and not likely if at all posssible to happen at low RPM's and not higher RPM's. I'd be interested in hearing a sound clip or your car.

NismoPick

wait... you don't know what a big diesel engine sounds like? Shame on you. You are supposed to magically know what each weird noise sounds like.

snwbrderphat540

LOL, totally. Cause diesels only make one different noise

ZXGrinch

Sigh....I am guessing I won't win the diesel sound thing.
But in effort to clarify more...since recording the sound is probably not a real option...maybe I will try, but not sure it will come through on a video.

The diesel sound I am referring to...is when you have a F250 diesel or RAM 2500 diesel next to you at a red light...they tend to make a very distinct sound of gurggling when they idle. That sound is pretty much unique to diesel trucks (and my car).

My car does not do that when idle, it only does it between 1.5-3k rpm and not all the time, just a lot more often then it should.

Sorry if this is coming accross as vague...I really am trying to describe it as best I can....I am going to put my camera in my car tonight so the next time it starts doing it loud I can record.

But on the upside...since I did the AFM fix...driving is even more fun.

NismoPick

The only thing I can think of would be a burnt & leaking exhaust manifold gasket...

Bleach

It very well could be pinging. Sometimes that does come in louder when you get on the throttle at low rpms and then goes away after that.
Advancing the ignition would likely increase the problem. I'd suggest you put in some mid grade (89) gas when you next to go fill up. Or just try a half tank. See if that helps.

ZXGrinch

Filling up in about an hour...so I will try that and see.

Thank You

ZXGrinch

I don't know that it is "fixed" but it is certainly less than it was.

Ok here goes a long story...for those who don't know...and to help for getting an explanation.

WHen my son was in 9th grade he had to do a science project, so I sujested to do a test on all of the different octanes of fuel. I was told when I was a teen that the octane rating meant how clean or pure the gas was...that lower rating meant dirtier gas.
So I told him that we will get 9 mason jars and get the 3 different grades from 3 different gas stations. The plan was to let the gas settle in each jar for a week and show the different levels of dirt in each octane and see the difference...then to burn them and see which burns cleanest. ( btw, filling up 9 mason jars at 3 different gas stations is a very eerie feeling....it is illegal to do so...i was waiting to be arrested for terrorism...try to explain why you have 9 jars of gas in your car.)

No dirt ever settled in any of them...as most of you are saying duh of course it wouldn't.

In the end, we saw no difference at all...so we looked up what the octane rating really means. Apparently the higher the octane rating the more pressure the fuel can withstand before combusting. Higher compression cars need higher octane so they dont combust before spark.

With that being said...why would I have this issue with a stock engine?
And how can I fix it, short of always buying higher octane gas?