Engines woes

[mhuk]

My week gets better.

Alternator woes
lost my job (Thanks Covid)
engine woes now

Here's the deal.

Engine was fine. Drove 60 miles down south and my air fuel ratio gauge displays ---- which means excessive lean condition. The car felt ok to drive but when it started to idle fast when clutch in or in neutral.

Leaning on the power felt fine too.

Next morning I stuck my smoke machine on the car. I can see smoke coming from one injector port on the manifold so I thought great it's only a seal.

I reckon the reason for the seal wear is because of several things.

I have poly mount so everything shakes more. I have a aftermarket fuel rail which shakes because the ****ing mounting scew was loose.

I have ordered a set of seals as on closer inspection 2 others are looking damaged. These have not turned up so out comes the bodge!

I used instant seal around all the injector ports. Now I have no leaks. The idle is OK but it's hunting slightly. I found the throttle switch was not always clicking when throttle was moved. Removed and put back again and now that's OK clicking.

Here's the thing.

It idles OK mostly but it's hunting slightly by 100rpm or arounds. The exhaust has a blow after the cat which is sealing now but gasket seal.

The air fuel gauge is showing ---- excess lean. I'm hoping it's because the exhaust leak is sucking up clean and giving a bad reading but it's a good 4 feet down stream from the air fuel o2 sensor.

I must say I'm getting beyond with thius car. I might go back to my mark 1 audi TT.

Sometimes I wish I had never started.

Grrrrr

So what else might cause a lean condition?

[TonyS9]

Fuel pressure
O2 sensor
Faulty injector
Air leak

what AFR gauge and sensor are you using?
Which Engine/car? Any other mods, why do you have an aftermarket fuel rail?

Certainly exhaust leaks will suck in fresh air.

[Laird Scooby]

Tony has nailed the most obvious problems ^^^^^ but also check between the MAF and throttle body (including the AICV pipework) for pinholes, splits etc that may not cause a problem under load (or even under boost) but might provide enough of an air leak to cause problems on idle.

There was another thread similar i think by Ovlov (not sure of his screen name) that turned out to be an exhaust leak downstream of the Lambda and upstream of his AFR sensor. His is also modified.

Good luck finding another job, can't be easy at the moment!

[mhuk]

Fixed. Leaking o ring on injector. Tha ks guys

[TonyS9]

Originally Posted by mhuk

Fixed. Leaking o ring on injector. Tha ks guys

Excellent, where did you get the o-rings? I been thinking of refreshing mine.

[mhuk]

https://mrinjectoruk.co.uk/ or turbonoz.co.uk.
But im using bkue t5 injectors.

[Chooch84]

The size of the seals they are 14.58mm outer diameter, the cross-section is 3.53mm and they are made from "Viton®". You should be able to get hold of these separately. Although the kits do include the filter baskets and the pintle caps/washers.