Misfire

[flyerncle]

Is there a fuel pump cut off on the TPS .

[j.brownster79]

Have u changed the belt recently? Was it ok one day then not the next? Is it more noticeable when the engine is hot? It sounds like a maf sensor but it may be worth checking things like fuel filter fuel pump delivery if the new maf doesn't fix it also if it does it when it is hot what plugs u running? They could break down when hot. Just chucking out some more ideas and hope u get it fixed soon which I'm sure u will it is starring u in the face laughing at you like these faults generally do!

[CTWV50]

Originally Posted by Davidbolam

I'm still waiting for the new afm to arrive. In the meantime I decided to get my haynes manual out! Totally forgot to look in there...

I have tested the resistance of the potentiometer in the afm and it's bust. There is no movement on the multimeter until it is fully open. The fuel pump switch operates as soon as it is opened.

The thermistor also seems to be not giving a reading.

I have had a good "dismantling session" in the kitchen tonight and think this must be the cause of the problems.

Ie when the throttle is opened there is no change in the fuel supply causing it to miss and the thermistor is most likely confusing the situation as well (without the ecu knowing as there was no error code showing for this)

Let's hope Hermes turn up tomorrow with my parcel!

David

Very good. Well done. Fingers crossed. Have you applied for your IVA yet?

[Davidbolam]

Originally Posted by flyerncle

Is there a fuel pump cut off on the TPS .

The fuel pump cut off is a micro switch in the afm. As soon as the vane moves a tiny bit the fuel pump works.

Still not applied for my iva yet. I want to sort out all these niggles first.

[Davidbolam]

Originally Posted by j.brownster79

Have u changed the belt recently? Was it ok one day then not the next? Is it more noticeable when the engine is hot? It sounds like a maf sensor but it may be worth checking things like fuel filter fuel pump delivery if the new maf doesn't fix it also if it does it when it is hot what plugs u running? They could break down when hot. Just chucking out some more ideas and hope u get it fixed soon which I'm sure u will it is starring u in the face laughing at you like these faults generally do!

In the diagnostics port you can override the fuel pump to test it's operation and that side is all working fine.

Thanks for the ideas

David

[Davidbolam]

We'll.....

I have changed the air flow meter and the misfire is still there!

I'm now stuck for ideas.

I'm thinking there may be a link to my base idle. Since I adjusted this as per the manual the problem seems to have for worse

David

[CTWV50]

My guess, and it is a guess, is a blocked or faulty injector. Is it one particular cylinder or random?

[Davidbolam]

Originally Posted by CTWV50

My guess, and it is a guess, is a blocked or faulty injector. Is it one particular cylinder or random?

I think all of them

[CTWV50]

Originally Posted by Davidbolam

I think all of them

Daft question but you don't have your HT leads mixed up do you? Does it idle ok but when the throttle opens is stutters?

Can you film it?

[CTWV50]

Are you still getting an AFM error code? Have you cleared the codes? Have you checked the wiring to the AFM?

I'm just thinking out loud in the hope it might help you to find the issue.