Hi Everyone

(Initially posted this enquiry elsewhere - being new to the forum. More relevant here...)


The Problem :

1984 Datsun 280C (fuel injected)

After it's been driven for about ten minutes it's stalling when it pulls up at a street corner or traffic lights i.e. won't idle. Konking out with all warning lights coming on. However, can usually be started again immediately. Only way to prevent stalling is to keep the accelerator slightly depressed (thereby keeping the revs up), while (obviously) holding my other foot on the brake (drag racing style !). No sign of over heating or boiling. No smell of fuel

General Points :

First start up each day : Usually starts first time (also after having been parked when I'm out and about during the day), although does have a worn ring gear so it occasionally "squawks" if the engine stopped at that point where there are no teeth. Blows smoke on first start up (only). But can't see any water or oil coming out of the exhaust. Idles quite OK in Park, Neutral and Drive (in the driveway)

Runs fine until it's been on the road for about ten minutes then starts to stall when I stop at street corners and lights.

Recent Service History

Fouled spark plug replaced
Engine was steam cleaned (wondering about the advisability "all that")
New fuel injectors & battery installed
Checked for water loss and oil leaks
New water by - pass hose fitted
Rocker cover gasket checked and refitted

Possible Issues ?

Other Spark Plugs fouled
Coil
Oxygen Sensor
Choke /Mixture
Vaccum seal
Fuel vaporizing
Fuel Pump
Distributor
Thermostat (although , as mentioned, no sign of over heating)
Coolant leaking into combustion chamber

Diagnostic Checks

I'll fill the radiator right up with coolant at night and see if the level has gone down substantially by the morning

Have entire cooling system checked

Summing Up

It's as if something is closing completely, shutting down or, possibly, expanding (?) when the car warms up. Maybe a coil problem ?

Any general thoughts/ suggestions before I go back to the service place would be appreciated

Thanks

Bruce

Sensor or even blocked fuel filter possibly.

Yes, could be. I tend to think an oxygen sensor maybe

Any updates??

Evening

Going in tomorrow. I'll post an update when I know more

Cheers

Been into the workshop this week.

The story I've been given is that there's oil leaking into the cylinders and it's fouling the spark plugs. Guy who owns the place has advised that to fix the problem properly is going to be a big and expensive job and, in view of the fact that the car has done nearly 400,000 Ks, that it simply isn't worth doing.

He's installed a full set of new plugs but he's explained that it's only a matter of time before they get fouled up as well.

He's of the opinion that it's time to move on.

Does all this sound reasonable or should I get a second opinion ?

Cheers

Although, wouldn't fouled spark plugs only be an issue in regard to starting the car ?. And, if they are the problem, how is it that I can start it again almost immediately if it stalls ?

Check the plug heat range. Std is BP6ES, replace with BP5ES.
change engine oil and use.
http://www.fuchs.com.au/ProductDetail.a ... t_id=37376

_________________
A little knowledge is a dangerous thing.
www.datsport.com

"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT

So does it stall with the new plug fitted, before they foul?

_________________
A little knowledge is a dangerous thing.
www.datsport.com

"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT

Hi

Only had the new plugs in for a day . I'll have to see how it goes.

If the plugs were serioulsy / heavily fouled they wouldn't be able to start the car would they ? Couldn't I just pull them out and clean them when and / if they do get fouled again? Although I understand that this is not fixing the main problem which is oil getting into the cylinders... or so I've been told... it's simply painting over rust

How is oil getting in? Ring and blowing smoke or past valve stem seals

Not sure. The bottomline seems to be that the car is just not worth persisting with.

Is it possible that the idle mixture is just wrong, when cold and choke is on it gets enough fuel and when choke is off it Dosent.... If the car is otherwise fine just adjust the idle when the car is warm till the point it runs. Also I wouldn't listen to the mechanic, you should be able to get a replacement engine in reasonable condition for fairly cheap (disadvantage would be getting it fitted, if you are confident in doing it yourself it would be worth while.) how much do you like the car?

L-series engines are tough as hell, its not that big job to change piston rings and valve guides if those are the symptoms for engine failure. I took out my engine in 1.5 hours (its a Z but same engine) 42 years of revving and burning rubber and still going strong as ever!