Hi all

 

As some of you know I recently got my car back on the road.

 

It's running spot on except for a couple of little things that I think are all connected ie a leaking injector(s)

 

Here are the symptoms and issues

 

- the car is hard to start. It turns over more than expected then splutters into life. Then runs perfectly

- fuel pressure drops off immediately after stopping the engine. It should hold for hours. I guess this explains the above

- one/both of the O2 sensors sit steady at 0.8v at idle- raise the revs a bit and they dance around as they should ( brand new Bosch)

- the car smells rich at idle- on the mot test, Co came out around 1.75% (too rich I think)

- after giving the car a bit of a Rev at idle a slight misfire develops, then clears in a few mins.

 

Things you should know

Almost everything else is brand new/good- loom, gaskets, plugs, timing belt (correctly set)

The car is setup correctly- timing, throttle voltage and switch, icv.

All deletes are done

Consult is clear of codes and as it should be.

No air leaks (maybe a few high pressure small ones)

 

Before installing the injectors I ultrasonicaly cleaned them and installed new orings

 

In my haste to get it back together I did not clean out the (new)fuel lines- this already caused a blocked injector which I sorted and it ran well after that.

 

I'm back in Hong Kong now so I can't really go and check up on it but I have lots of time to think about how to get it running perfectly.

 

So maybe I have answered my own question but I'd like a few more opinions.

 

I will probably buy a new set of 550s and get a nos tune when I'm back but I want it spot on first.

Skim read that a bit, but.

 

If you think you have a leaking injector

 

If you can hear Squealing (like an old radiator being bled)

 

If you can smell fuel

 

DO NOT DRIVE THE CAR.

 

I got my zed with a leaky injector. The very recently replaced rear injector had been put in with the plenum in place. During instalation the O ring had got nipped, rolled up a bit and split.

 

Over 3 drives it went from a quiet squeak after shut down, to a smell of fuel and a gurgling noise, to fuel coming up in a jet and hitting the underside of the bonnet like a karcher jet washer.

 

How I didn't end up on fire I dont know!

Before suspecting the injectors you may have fuel getting into the cylinders from another route, a very common issue is the fuel rail damper, when the diaphragm in this fails it drops fuel into the plenum after switching off that gets sucked into the engine upon restart and can cause a non start from flooding or just hard cranking with a misfire that clears when revved, of course when the engine is running the fuel is been burnt more quickly, it does however have the ability to cause an occasional pulse misfire and effect the fuel pressure stability.

 

Testing the damper is simple, remove the vacuum pipe attached and wipe you finger over the end of the pipe if its wet or smells of fuel then it leaking, do try this several times after been left, when its running and before and after a run as the little blighters can just leak intermittently, replace it and all will be good and often the improvement extends across the whole running range which is great as they are not that expensive.

 

Jeff

Thanks for the top tip Jeff

 

Unfortunately in my case I have no fuel damper so it can't be that.

 

I converted my fuel rail to -6 fittings and I'm running an aeromotive FPR with gauge

 

 

It's also not an external leak but thanks Tom for the warning

 

I guess it has to be either thr FPR, injectors or the check valve at the pump

Okay, can I ask why no damper?

 

Jeff

My engine bay is very minimalist and I have removed as many (in my opinion) unnecessary parts as possible for both an asthetic and simplification/reliability.

 

I did plenty of research on this obviously before doing so

 

It currently looks like this

 

Wow that looks amazing, what fuel pump you running then? does it smooth out the typical pulse feed?

 

Jeff