Ok guys, again several issues, but i'll start with the most important and then do the rest in other threads.

 

Car was running perfect until i gave it a little snot, got it home and it started idling really badly, it now stalls if you leave it a few seconsd without compensating with the accelerator. While ildling it's badly misfiring, which is why it grinds to a halt.

 

I'll be honest i havent got a clue about it car, it like learning Japanese (pun intended). Where are the HT Leads? Spark Plugs?

 

I've looked on a few other threads and you guys keep mentioning the O2 Sensor? where is it and what does it look like?

 

Desperate here guys, i dare not drive it until its sorted.

Does it sound rough when you use the accelerator to give it some revs - lumpy?

This sounds like your'e not running on all 6 cylinders. Could be a coil problem, an injector problem, a spark plug problem, or a PTU problem.

 

First - the 300zx doesnt have ht leads - the engine is Direct Ignition - each spark plug has its own personal coil that sits on top of the spark plug - which is why you cant see them. You will see in the engine bay from the top 6 metal brackets with 2 bolts each on them These are the coil packs - next to them sat lower down will be the injector connectors. Try wiggling all the wires you can see while the engine is running and see if it improves the idle - if it does you need to clean up all the connectors as they get full of corrosion over time. If none of that seems to help do a search for the PTU as this can go funny - start by cleaning the connectors on that as well. The PTU problem usually manifests itself when the engine gets warm - as it all cools down the problem can go away for a short while, and then come back.

 

Good luck!

Thanks, very informative response, much appreciated! :bow:

Give the water temp sensor cable a wiggle, or give the sensor a little clean. I had exactly the same trouble as that when the temp sensor wasnt working.

ok will try that.

 

What should i use to clean up the connectors? I heard WD40!

You can buy proper electrical connector cleaner in a spray, I found it in the motorbike section of Halfords for some reason :)

Check to see if the coil pack conectors are all plugged in mine popped off a few times when i put my foot down only one but that could be the problem.

Also check that you didnt blow off one of the many small hoses and give yourself an air leak. Any hissing around the battery area when its trying to tickover. Sometimes these small hoses can even burst with boost pressure and old age.

 

And for cleaning up connectors I found you had to use those tiny screwdrivers like in watchmakers stuff to scrape the oxide from the inside of female connectors and the outsides of the spade ends. Then a smear of vaseline to protect afterwards.

definately first check if any th coil pack connectors havnt come loose, that happened to me last week on the way to huddersfield. not nice, very very shaky when accelarating at lows revs over 70mph.

had same lumpy symptoms when one of th vacuum hoses came off, great help from this forum and a hand from berks sorted that

No luck, tried the water temp sensor cable and connector, cleaned it up too cuz it was badly corroded, no change.

 

Took battery of to reset ECU for 1 hour, no change, a little worse in fact.

 

The car isnt smoking at all either.

 

But i did find this, around the back of the engine, what this connector go to:

 

No luck, tried the water temp sensor cable and connector, cleaned it up too cuz it was badly corroded, no change.

 

Took battery of to reset ECU for 1 hour, no change, a little worse in fact.

 

The car isnt smoking at all either.

 

But i did find this, around the back of the engine, what this connector go to:

 

 

as posted in your other thread mate it def looks like the detonation sensor harness/connector......and investigate the smaller hose below i think it wants to be connected to something:p

 

jaz

That hose IS connected :p Just a rough end on it but its one of the many under plenum coolant hoses ;)

That wire - its not rear plenum passenger side nearby the battery? Because it could be related to the Idle Air Valve. If thats not working anymore it could explain the lousy tickover. The ecu controls that valve to keep the tickover stable at 700 ish rpm if set up properly.

I had this problem on idle where it just kept bloody stalling after a few seconds.

 

Apparently Option motorsport traced it to the fuel pump wires (earth) or somet being faulty.

 

May be worth giving them a ring, as I am sure this sounds very similiar to my problem.

 

OPTION MOTORSPORT @ Silverstone Race Course.........not sure what the number is. I used to know if off by heart! Ask for Myer...pronounced mi-er. HTH ;)

That hose IS connected :p Just a rough end on it but its one of the many under plenum coolant hoses ;)

 

Duffman to the rescue again:slap: Andy you reck that det sensors been bypassed if so who do you reckons been at it :rofl: :x:

Duffman to the rescue again:slap: Andy you reck that det sensors been bypassed if so who do you reckons been at it :rofl: :x:

 

We are watching you :nono: LMAO !!!! :rofl:

We are watching you :nono: LMAO !!!! :rofl:

Hi

 

At the risk of sounding daft I suppose you have checked your TPS has not become disconnected or packed up?- without it your ECU has no idea of what your engine is doing!

 

Regards,

 

Dave

TPS? Whats that and where is it? How do i check if it has packed up? Presumably i unplug it with the engine running?

 

Any pointers.

If thats the TPS sensor, i've unplugged it with the engine running, makes absolutely no difference.

 

If thats the TPS sensor, i've unplugged it with the engine running, makes absolutely no difference.

 

 

Right part- Throttle Position Sensor!

 

On most cars the ECU depends on this to determine management for the engine -a basic potentiometer- 3 copper strips with a contact moving across them. On a lot of cars and while we've got rid of distributor contacts and other wearing mechanical parts for some reason you still find these! They wear and break down but arn't changed like points used to be as a matter of course.

 

When I unplugged my own engine it ran like sh.......t - couldn't idle etc- which if you think about is obvious because the rest of management has little info about throttle opening and can't regulate fuel etc.. Possibly therefore yours has packed up and it shows these symptoms and continues to show symptoms when unplugged- bit like taking the lead off a faulty plug and no change in engine firing showing faulty plug.

 

About £20 second- hand and if changed needs setting up- simple job-detailed in advice search on Forum under TPS. Cheap possibility especially if you can borrow a proven good one to try! Could be worth a try?

 

Regards,

 

Dave

You really need a ConZult/Consult on the car at the time that the problem occurs. Then you can monitor the TPS voltage or the idle valve % opening etc in order to identify the problem.

 

Andy

I unplugged my TPS today with the engine running, it also made no change to the engine, so is mine knackered too??

 

I pulled the hose off by the bulkhead near the battery, idle conrol one i think, and this causes the engine to stall, unless you keep the revs up, so i think that if your car is stalling maybe you should check all the hoses near the battery for a leak.

 

Im trying to find the opposite solution to these promlems, maybe i could trade you a bit of your stalling for my high tickover!!!

I unplugged my TPS today with the engine running, it also made no change to the engine, so is mine knackered too??

 

I pulled the hose off by the bulkhead near the battery, idle conrol one i think, and this causes the engine to stall, unless you keep the revs up, so i think that if your car is stalling maybe you should check all the hoses near the battery for a leak.

 

Im trying to find the opposite solution to these promlems, maybe i could trade you a bit of your stalling for my high tickover!!!

 

Lol, Nice of you share the same symptoms as me when the TPS is unplugged, does this mean that my TPS is ok, If yours is doing the same when unplugged....NOTHING.

You really need a ConZult/Consult on the car at the time that the problem occurs. Then you can monitor the TPS voltage or the idle valve % opening etc in order to identify the problem.

 

Andy

 

Got one coming Tuesday mate!

Right part- Throttle Position Sensor!

 

On most cars the ECU depends on this to determine management for the engine -a basic potentiometer- 3 copper strips with a contact moving across them. On a lot of cars and while we've got rid of distributor contacts and other wearing mechanical parts for some reason you still find these! They wear and break down but arn't changed like points used to be as a matter of course.

 

When I unplugged my own engine it ran like sh.......t - couldn't idle etc- which if you think about is obvious because the rest of management has little info about throttle opening and can't regulate fuel etc.. Possibly therefore yours has packed up and it shows these symptoms and continues to show symptoms when unplugged- bit like taking the lead off a faulty plug and no change in engine firing showing faulty plug.

 

About £20 second- hand and if changed needs setting up- simple job-detailed in advice search on Forum under TPS. Cheap possibility especially if you can borrow a proven good one to try! Could be worth a try?

 

Regards,

 

Dave

 

Where can i get one mate, FAST, ASAP?

Errrmmmm hang fire one minute - which plug did you disconnect? Its the GREY plug on the flying lead you need to unplug - the other is simply the hard idle contacts and won't really affect anything that much... ;)