Injector leaking?

Symptoms of which would be.. Shut the engine off and the injector leaks fuel into the cylinder, start the car within an hour and not enough fuel is in to cause a flooding issue. Leave the car for let's say over 5 hours and enough fuel has got in to cause flooding and then poor starting. Also if is happens, if you leave the car for a number of days, there's a time that passes where the residual fuel pressure in the rail has dropped enough to allow the injector to stop leaking and then past that time the excess fuel can evaporate. This also ties in to you leaving the throttle open and it starting better (fuel able to evaporate if you got lucky with valve position)

Ways to diagnose a leaky injector at home... Either leave the car a couple of days and if it starts better then that's a sign. Or if you're ok with fettling, when you turn the car off, undo the fuel line by the filter to relieve residual fuel pressure and hopefully prevent the injector leaking under any residual pressure. If it starts ok the next day, another sign. Of course, it may be that the injector will still leak without pressure.

Might be worth considering.

 

A leaky injector was one of my first thoughts but the problem continued after an injector change! It's possible that there was a leaky injector in both sets but the odds are pretty slim?

JohnD

 

Tbh I want to avoid changing injectors.

It is a bit bizarre as the car is serviced every 5,000 miles by Paul and otherwise in tip top condition, he can't find a fault and typically it refused to surface when the car was with him!

Last week it had a full service and cam belt change. It is a bit better, but typically may be a tiny bit hesitant. However, turning on the ignition and leaving the car for about 20 seconds before starting seems to cure it just fine.

The real test will be when it gets properly cold.

 

It might not be the injectors, but it may be worth trying a bit of diagnosing.. Just saying "Tbh I want to avoid changing injectors" isn't going to make the problem go away lol.

 

Lol, ok I might take the investigation further!

 

Since my last post I haven't had much chance to investigate anything more, however the service / cambelt change appear to be making an improvement.

At the time of the service it struggled a little to start, but now it hasn't struggled to start once, although in each instance I turn the ignition on and leave it ten seconds before starting the car.

Nothing else, however, has changed. I still use VPower. Use is a mix of frequent and in frequent. Left her standing 5 days and she started just fine.

I do worry that there is a minor drain on the battery however, and will investigate that further with my multimeter.

 

There will always be a slight drain as the stereo memory, clock, ECU, tracker, alarm etc are live. A healthy battery will cope fine but if the car's left for a week or so it's worth investing in a smart charger -eg C-Tek.

JohnD

 

I'D CHANGE FUEL PUMP FOR A RCM ONE MUCH MORE RELIABLE THAN A WALBRO, AND GET THE ALTERNATOR TESTED AS THIS WILL BE DRAINING THE BATTEREY IF FAULTY.

 

I've just switched to a tank of momentum and it's started better over the last week.

 

I suggested fuel. cant understand why he hasn't tried it yet.

 

I like this theory ^

Also,have you tried just feathering the throttle whilst turning it over? Instead of leaving stick on it overnight. When mine occasionally doesn't start instantly with similar issue to you,i just give it a little gas and it starts.

 

Because I actually have a life rather than worry about hunting down a Tesco. I'm sure I will give it a go when I get a chance.

 

Yeah I have tried that and if she is struggling to start it definitely helps.

But that isn't a solution to the problem, just an aid to rectifying the existing problem momentarily.

 

Had the alternator tested, it got a clean bill of health.

Battery is a top notch brand new Bosch.

Time to investigate if anything irregular is creating a drain.

 

If the battery is spinning the motor over ok then even if there is a drain, it's not the problem.
As I said in a previous post, you will find there is a drain as there are live circuits. I tested mine and IIRC it was around 110mA without the alarm armed.

JohnD

 

I'd definetley change the fuel pump as ive had a few faulty walbro's in my time ive had the rcm one in never had a problem running 380bhp and always use shell v-power, i'd check the connections on top of the fuel pump aswell just under the rear seat maybe a dry connection, but the fuel pump is definetley the culprit as the alternator is fine and the batterey is holding charge but the fuel pump aint got enough pump.

 

Of course you are right it isn't a solution but might be easier than the stick idea

What jameswrx says about injector problem,makes sense to me and would get that looked at. I think if mine ever done it alot I'd get mine checked

 

Thanks to John posting link to my thread in here, seems we have the same issue.
Tried all of the above including replacing the cam & crank sensors and the CTS, also checked the fuel pressure and fine the mention of drain on the fuel system is interesting and think I will rig up gauge to see if this is the case.
The mention of leaking injector now seems possible but when mine does this I have a puff of blue smoke?
It does seem that it depends on the cycle of the stroke the engine stops on.

 

Blue smoke. Could oil be getting past the rings? Do you have high miles,or even a forged engine (usually a rebuilt one) Due to expansion reasons,forged are usually undersize pistons that expand when hot but could let oil by when cold,causing puff of blue smoke when started