help needed-another poor git running lean

[chrism]

Took the car out tonight and noticed it was spluttering.Started spluttering more and check engine light came on.Stopped and checked under bonnet,ok,started car again and set off home.When I got home i switched the car off and it kept running a couple of secs.Then it took 4 or 5 secs to start when I drove into garage.

Checked the plugs and they were white.Checked dissie cap and it was all rusted on the tips inside,so I cleaned it thinking it was only that.Took it out for a slow drive to check plugs afterwards.They were still pure white.
I have now checked fuel pump works.I removed it from tank and applied 12v to the terminals.It went round.Checked all fuses as well.Not sure if the relay to the pump is okay,not sure how to check.

Question is: Whats the next step to take?
How should I now go about searching whats wrong?

 

[oap-r]

When did you last change the fuel filter?

Try the simple things first ;-)

 

[chrism]

I changed it last week.

How do I check fuel pressure? What is the best way to check if pump is actually working?

 

[Fusion Ed]

Show us a pic (good one if possible) of the plugs. The centre electrode should be white with a black rim around the bottom. The earth electrode should also be clean down to about the bend to show the heat range is correct.

 

[deslynam]

Just check the voltage across the power feed outside the tank when it's in place.

 

[pulsarboby]

if the cars running on when switched off this will indicate it is either running far too hot (overheating) which is another reason for the plugs being excessively white!

another cause of this is your distributor timing could be out, this will also cause an engine to run on, as the mixture will pre-ignite even after the engine has been turned off!

guarantee it wont be a fuel problem

 

[Fusion Ed]

if the cars running on when switched off this will indicate it is either running far too hot (overheating) which is another reason for the plugs being excessively white!

another cause of this is your distributor timing could be out, this will also cause an engine to run on, as the mixture will pre-ignite even after the engine has been turned off!

guarantee it wont be a fuel problem

The pulsar cannot run on after its turned off, the fuel to the injectors being off.

 

[pulsarboby]

but he said it is running on for a couple of seconds!

 

[Fusion Ed]

leaking/stuck injector? don't really know what to say to that. No power to ecu = no injectors, but to run on is very strange!

 

[pulsarboby]

if there is a carbon build up in the combustion chambers ed, then the car will run on if it has
1. overheated
2. has ignition timing out

the carbon embers will carry on burning any waste fuel remaining in the chambers, i have seen cars in the past which have run on for over 10 seconds with ignition key removed and fuel shut down!
it isnt so much a problem nowadays though due to improvements in fuel and engine oils which dont produce huge carbon deposits, unlike old 4star and 20w/50 oils.

theres a thought! have you been using crap fuel and engine oil chris? over a long period of time! if so then you will probably have a big carbon build up on your head and pistons, if so pour some fuel injection cleaner down your plug holes mixed with a teaspoon of engine oil, put the plugs back in (no leads) and crank over engine for 2-3 seconds, then leave car for 24-36hrs
(once its simmered n boiled lol)after that time, remove plugs, put an old sheet over engine and crank it over, this will loosen and blow any crap out of your plug holes, put plugs back and away you go! car may smoke for a few miles, but will eventually burn off!

 

[Fusion Ed]

I've never seen a car running on after its turned off which is an injection. I wouldn't accept that there could be enough fuel to continue burning after a combustion cycle event has taken place, with the injectors closed. If that were the case as the next cycle begun the fuel would ignite before it even reached the top of the next compression stage and pretty quickly destroy the engine. I have however seen cars on carbs, that would not turn off when the ignition was removed (a shed of an old R5) that was very funny, and it quickly blew ts headgasket too. I ran a moped once on 'nitro' model car fuel/petrol mix that also kept going - and driving around after the ignition was off and the spark plug lead removed!! Also added about an extra 10mph to its top speed haha

 

[pulsarboby]

unfortunately your wrong ed!
i have never seen this problem on an R before, granted! but the cvh rs turbo was noted for running on as they did suffer from massive carbon build up, i have seen them so choked up that even the top of the head near the rockers has been full up with carbon deposits, which you have to chip out as its solid!

the merc sprinter van is another that is notorious for it!
and yes your right the fuel remaining does ignite before tdc which is very bad as you well know. if you listen to a car whilst its running on you will hear it pop and bang from exhaust and airbox due to firing off stroke half way up the cylinder.

 

[Fusion Ed]

Im happy to be wrong, as long as its proven! I would have to go and see this car as to see how this could be happening. Until that time I wouldn't rely on an a statment that could be caused by many as yet unknown external factors...

 

[MarkTurbo]

The pulsar cannot run on after its turned off, the fuel to the injectors being off.

Is that in the same way as the standard ecu cant take more than 1.2 bar :lol: :lol: :lol:

 

[chrism]

Thought I d just say that in hindsight it was probably not 2 secs of afterrun.It was more like a short moment.Probably caused by it overheating due to running lean.
Ive now checked fuel pressure and its fine.Both regulator and pump are getting up to the right pressure.
Cant be too many things left.O2 sensor and MAF.

How do you measure if the lambda is working properly?Is there a sure fire way to check the operation of these?
Would be nice to be able to say for certain that its knackered.