I have an 1989 3.5 efi RRC with a flapper AFM. If I take all 8 plugs out and wire brush them clean, it starts on literally the first crank of the engine, and will run for about 1 -2 minutes then cough and splutter and then dies. I can get it to start again after cranking it over a bit, but it'll only go for about 30 secs, then dies, and that will be it until I take out all the plugs, which are now sooted up and wet with petrol, and I clean them off again and start the process all again. This is a long ongoing project, which allways used to start fine, as I would do this once a month to keep it going. It has a had a new / recon ECU from Carselect, new dizzy,(Lucas arm and cap), leads, coolant temp sender. I have a spare AFM which I have tried both of, with the same results. I am at my wits end with it now! I've been tempted just to get rid of it cos its been driving me that mad, but I can't get the damn thing started to get it out of the garage where its stored!! Any ideas what I can do now would be most grateful???

iainmcb said:

It has a had a new / recon ECU from Carselect, new dizzy,(Lucas arm and cap), leads, coolant temp sender. I have a spare AFM which I have tried both of, with the same results. I am at my wits end with it now! I've been tempted just to get rid of it cos its been driving me that mad, but I can't get the damn thing started to get it out of the garage where its stored!! Any ideas what I can do now would be most grateful???

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Would suggest you look at ignition amplifier and coil and all the connections in between. The other thing that might be related is the fuel pump and or relay. If there is something causing the pump relay to play up it could cause the sort of thing you have a problem with but I think you need to start with the ign. amp and coil.

Get a multi meter and check continuity for sensor inputs and check the resistances and voltages for the EFI components, details can be found in the Haynes book of lies which is surprisingly useful for this. You might also get some pointers from RPI Engineering website and another place to look is the v8forum.

Good Luck.

iainmcb said:

I can get it to start again after cranking it over a bit, but it'll only go for about 30 secs, then dies, and that will be it until I take out all the plugs, which are now sooted up and wet with petrol, and I clean them off again and start the process all again.

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Hello Iain,
You clearly have reliable sparks because the thing starts regularly and even tries to burn the fuel into those sooty deposits before it croaks and drowns in excess fuel.

So your engine is overfuelling continuously and you have to look at all the things that will cause that fault. ie - temp sensor, pressure reg, throttle pot, AFM and ECU. They can all be tested (but the ECU which is best checked by substitution).

Trust nothing, just because you have fitted new or replacement items means diddly-squat. The potentially faulty units should be tested to establish their integrity unless you can find a fire-sale of cheap components and you will find everything you need in this index.

Rover SD1 Efi System Components

which covers most of the components on your system.

One final note at this stage, the majority of all Flapper Efi faults are caused by air leaks and electrical connector problems. True, air leaks dont usually cause overfuelling but the ECU cannot always be sure what is happening when they exist and can be fooled, so check for rogue air leaks too.

Specifically the whole air leak subject is covered in fine detail in the Plenum article from the mentioned index.

Elsewhere on the site are instructions how to test for and deal with Efi loom, wiring/connector issues.

Ramon
Vintage Model Airplane and Rover SD1 3500cc Twin Plenum Vitesse

classic kev said:

Would suggest you look at ignition amplifier and coil and all the connections in between. The other thing that might be related is the fuel pump and or relay. If there is something causing the pump relay to play up it could cause the sort of thing you have a problem with but I think you need to start with the ign. amp and coil.

Get a multi meter and check continuity for sensor inputs and check the resistances and voltages for the EFI components, details can be found in the Haynes book of lies which is surprisingly useful for this. You might also get some pointers from RPI Engineering website and another place to look is the v8forum.

Good Luck.

Click to expand...

Thanks, I'll get my meter this weekend and start probeing deeper

ramon.alban said:

Hello Iain,
You clearly have reliable sparks because the thing starts regularly and even tries to burn the fuel into those sooty deposits before it croaks and drowns in excess fuel.

So your engine is overfuelling continuously and you have to look at all the things that will cause that fault. ie - temp sensor, pressure reg, throttle pot, AFM and ECU. They can all be tested (but the ECU which is best checked by substitution).

Trust nothing, just because you have fitted new or replacement items means diddly-squat. The potentially faulty units should be tested to establish their integrity unless you can find a fire-sale of cheap components and you will find everything you need in this in
Rover SD1 Efi System Components

which covers most of the components on your system.

One final note at this stage, the majority of all Flapper Efi faults are caused by air leaks and electrical connector problems. True, air leaks dont usually cause overfuelling but the ECU cannot always be sure what is happening when they exist and can be fooled, so check for rogue air leaks too.

Specifically the whole air leak subject is covered in fine detail in the Plenum article from the mentioned index.

Elsewhere on the site are instructions how to test for and deal with Efi loom, wiring/connector issues.

Ramon
Vintage Model Airplane and Rover SD1 3500cc Twin Plenum Vitesse

Click to expand...

Thanks very much for your reply, I have had a look at your pages and they appear very helpfull. I'm sure that I'll find the answers to my problems in there somewhere.
Many Thanks
Iain

Leaking injector(s) might also cause such phenomena. I'd especially check cold start injector on the side of the plenum. Just disconnect, remove and pressurise the fuel rail (ign on, push AFM flap gently) and observe.