Car Stalls.... Sometimes.... 89 Skyline

[Strat]

Posted this at another forum I frequent but thought you guys might be more knowledgable. Any help would be appreciated.

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Hi guys. Got a few issues/questions but will try and keep this post structured. If I am unclear or you need more information please ask.

Car: 1989 Nissan Skyline - Auto.

Parts Changed without resolving the issue:

• Spark Plugs
  
• Leads
  
• Oil/Oil Filter
  
• Fuel Filter
  
• Air Filter
  
• Injectors are only ~20,000k old. Although they were replaced 6 months prior to the fault occuring.
  

Issues Occuring (possibly related/unrelated

1. When the car is first started it idles smoothly most of the time (around 800-1000rpm) but every say 10-15 seconds it will kind of shudder and the rpm's will drop. The car won't stall and it quickly returns to it's normal idle but it does this all the time when it is first started. Mainly when it's cold.

2. Okay this is the main issue. Sometimes when driving and coming to a stop the car will just start dying (idle rpm's drop) and then die. If I notice quickly and put my foot down it will sometimes not die but otherwise it will stall. It then usually takes a few turns of the key and a 30 second rest before it starts again. If it stalls it will often stall again if I come to a complete stop in the same period. It does this when the car is hot (so it's not an issue with it being cold)

It only does this infrequently. It has probably happened 8-9 times over the past 12 months.

From my experience it seems to occur mainly (although not neccesarily) when I drive for a period of time, say 5 minutes down the freeway 80-100kmph, and then come to a complete stop (say at an off ramp etc).

Any ideas? I am thinking possibly a sensor or something like that. I don't mind taking it to a mechanic but don't want them to charge me for not fixing the issue. And with the nature of the issue it may take a month or two for it to occur again.

Also I am thinking about taking it in for a 'tune' to see if it helps. But what exactly is a tune. What do they do? And would it help my issue at all.

I have owned the car for 3.5 years and it hasn't been to a mechanic yet. I do periodic maintenance though (oil, plugs et al). The engine is only 160,000km old.

Any suggestions would be appreciated. This is really starting to piss me off.

Cheers guys.

[boj01]

Maybe AFM or crank angle sensor. Are you running an atmospheric blow off valve.

[Strat]

i should have mentioned that the car is completly stock

thanks for your reply

[g0t $|{i||z?]

02 sensor ?

[SKY031]

Is the car a 31 or a 32?

"89 Skyline" could be either?

Also I am thinking about taking it in for a 'tune' to see if it helps. But what exactly is a tune. What do they do? And would it help my issue at all.

If you're running the stock computer, then there isn't a whole lot that can be done as far as tuning goes.

Check the timing.

If you have anyone in your area who is willing to come over and swap parts from their car to see if it makes a difference, then that's a good place to begin.

[Strat]

Sorry it's a 31.

A few people have suggester checking the fuel pump and crank angle sensor so going to have a look at those later today/

[SKY031]

oops... sorry about that, i started to edit my post and got sidetracked.... 20 minutes later i sorted it out. Silly distractions!

OK, now that I know it's a 31, I'd also like to point you in the direction of the fuel pump.

My car did a lot of strange things similar to what you're describing, it turned out to be the fuel pump.

The problem was intermittent, and went on for over a year before it died properly.

Have you noticed if the fuel pump noise has changed at all recently?

1/ check timing

2/ check fuel pump

3/ check cas

4/ check afm

I'll also throw in a recommendation for you to check the distributor cap and rotor button.

[Strat]

I did take the distributor cap off, and give it a clean etc but that didn't help.

Once I can motivate myself to get off my ass I will go down stairs and check the pump and a few other things that people have suggested.

Will let you know how it goes.

[Strat]

Okay did a few things.

First I checked the connector on the fuel pump. One of the wires (GND) had been cut and soldered together with some scrappy wire. I took off the wire, restripped them and soldered it properly.

Now I don't see how this would work but now when I turn the ignition just before kicking it over when the fuel pump kicks in, it is noticeably louder. Now it could be something to do with the few boxes I had in my boot previously but I don't think so. So very possibly the crappy join was the problem.

I took the connector off the crank angle sensor and it was dirty and slightly corroded (and wet). The boot was cracked. I attacked them with some sandpaper and bent the connectors a bit to make sure they make good contact. Also taped it up nice and tight to stop anymore water getting in.

Finally I took the Oxygen sensor off and replaced it with a new one I had lying around . The old one was a bit dirty and burnt but nothing over the top.

The car still seems to not idle as smooth as it could but it doesn't seem as bad as before. Than again I won't really be able to judge until the car is cold and I take it for a proper drive.

Thanks for all the help so far.

Now to show my noobness. If I was to take the car for a 'tune' at a mechanics what exactly would they do to it?

Cheers.

[rsx84]

ok i have had very similar things happen to my r31 before, the problem for mine is a plug to a temp sensor at the front of the engine, what my machanic said is this, if the sensor is'nt sending signals to the ECU the ECU shuts of the injectors and there for kills the engine, if the plug is loose and sending part signals then you'll be getting working injectors then non working injectors hence the coughing engine? this was fixed and the problem stopped.

[Sumo]

A tune?

Replace Plugs/Oil/Fuel filter/Air filter/reset the computer?/give your tail shaft a grease....

A tune isn't much for a general workshop.... But a EMS tune is a whole different scenario

Sumo

[Strat]

Okay another update. Sorry if make it short but had an absoloute shit day.

Anyway I took the car to the mechanics as it was still idling bad and stalling.

He put the engine on his little computer thing but couldn't find anything wrong. So he gave me a call and said it could be the computer but to get it tested would cost $100. I happened to have a spare new computer in the garage so I took it down and we switched them over, but it didn't make any difference

At that stage he noticed that he wasn't getting any reading on his machine from the 02 sensor. Even though it was a brand new one. He suggested that I should get a new, new one and see if it helps. I was a bit skeptical and thought perhaps his machine wasn't connected properly.

Anyway when I got the car home I took the oxygen sensor out of my dads car (an 87 skyline) and swapped with mine. His car is running fine with mine in it and putting his in mine has made no difference (car stalled today and the idleing is still screwy)

Anyway when I got home I unplugged the o2 sensor from my engine and started the car and it made no difference to the way the car ran. So my question to you guys is If you unplug the 02 sensor on an engine that is running fine, would it make a noticeable difference to how it runs?? I am starting to think that perhaps the cable connecting the o2 sensor to wherever it connects is screwed or something like that??

EDIT: I should note that I only unplugged the cable on the 02 sensor, I didn't unscrew it.

Any other suggestions guys? Are there any mechanics in melbourne that specialise with skylines or anything like that. It really is driving me nuts. I will probably take it back to this guy and see what he says although he really did seem stumped by the problem

Thanks.

[Sumo]

I honesty think that you may have a leak in the intake manifold... The old trick is to spray a bit of aerostart around the manifold (or where ever you may think its leaking) and see if the idle changes - if it revs up you've found it, if it doesn't, back to the drawing board....... You have to eliminate all the possibilities

Cheers

Sumo

[funkymonkey]

my car did that too, traced it back to too much gunk collecting on my AFM. (you could see a clog around the sensor). cleaned it off by dipping it in alcohol and the problem was resolved.

[Strat]

Funny you should mention that as I put a new AFM in yesterday and it didn't help.

Sumo when I get some time I will have a look at the intake manifold

Thanks.

[SKY031]

Anyway when I got home I unplugged the o2 sensor from my engine and started the car and it made no difference to the way the car ran. So my question to you guys is If you unplug the 02 sensor on an engine that is running fine, would it make a noticeable difference to how it runs?? I am starting to think that perhaps the cable connecting the o2 sensor to wherever it connects is screwed or something like that??

From what I understand (which probably isn't a whole lot) the O2 sensor doesn't do much while the car is at idle, so you probably wouldn't notice a difference unless you took it for a drive.

(If anyone can shed some more light on this, then please do!)

[CNBLOW]

have u checked the plug which connects to the dizzy....try cleaning to...i had dramas with that on my 31

[Scooby_Steve]

Hi,

Just a post to let you know my R33 has done it twice, so if anyone has any other ideas, let us know.

I was driving my car, turned it off to go into the shops. Came and restarted the car. Car kicked over, and then stalled. Restarted again, and then stalled. Did the same for one or two more times. I then did not let the car idle after restarting and drove home. I turned the car off and back on. hasnt done it again since... (Touch Wood!)

Again, any help would be great. Thanks

[Sumo]

Scooby_Steve: your car doesn't have an aftermarket immobiliser by any chance?

I have seen a few cars with problems like you describe, e.g. once hot the car wont start - I can range from things like crank angle sensors to the EFI module that controls the spark/ fuel.

In factory alarm setups, the immobiliser module acctually has the EFI module by the balls, and if it doesn't give the EFI module the green light, then the car will not fire.

Cheers

Sumo