Air Flow Meters-S4C

[MichaelM]

I recently bought an S4C and am beginning to sort out some of the little faults with the help of Steve Heaths book. The problem that is beating me at the moment is that the fuel mixture appears to be lean when the engine is cold with a tendancy to stall when pulling away from rest.Once the engine is fully warmed up all is fine. No fault codes on the EMU reader and the car has passed its MOT. The car does not have air flow meters or air temp sensors! I do not understand how the Ford EEC IV EMU can control themixture accurately without. Therefore I would like to fit a pair of AFMs and hope to improve the driveability of the car.
Will the EMU need to be sent to a specialist for programming or will a Ford garage be able to reset the unit?
Where is the harness plug on the S3?
Are these items Ford or Bosch does anyone have the part numbers?
Does anyone know of a good source for these units?
All help greatfully accepted by this new boy to TVRs. I wish to be back on the road soon.
MichaelM

[tozerman]

You can't fit AFM to these cars, the ECU will read signals given by both Lambda sensors which measures the mixture of the exhaust gases and adjusts it accordingly.
How do you know it is running lean when it is cold ?
If the car is still on its original throttle potentiometer then that could cause then symptoms you described(about £52 from ford)

Edited by tozerman on Sunday 30th March 14:11

Edited by tozerman on Sunday 30th March 14:12

[jimed]

I don't know if the slow running valve could be part of your problem but maybe cleaning it would help? Its the one at the front O/s of the plenum chamber; disconnect the plug then 2 small bolts and its off, clean out with petrol/carbcleaner and refit - you may need to get a gasket or make one from something suitable. They do get very dirty so maybe that's worth a try.
Jim

[tvrgit]

The S3C and S4C don't have air flow meters.

The mixture is controlled by the ECU depending on various inputs, principally the lambda sensors in the exhaust, the manifold absolute pressure (MAP) sensor, the throttle pot, etc. The car does not need to measure air going in - it measures excess fuel going out, basically.

You would have to remove the lambdas, the MAP etc, and I don't know if you also need a differewnt ECU.

As others have said, you'd be better fixing what you have. I'd go with the suggestion of the idle speed valve as suggested earlier, as a start.

If it's any consolation to you, though, my S3C is also crap when the engine is cold but fine when warm. I don't worry about it - it could also be engine temerature sensor (not the one that works the gauge) or a number of other things - if it's ok when hot then it suggests the ISCV or something else in the cold start system.

Edited by tvrgit on Sunday 30th March 20:12

[Barkychoc]

Welcome to the forum - I see it is your first post.
Out of interest is this your car?

http://www.pistonheads.com/sales/364464.htm

If so it looks a stunner.

Might be worth doing the simple things - a new set of spark plugs, plug leads, distributor cap and rotor arm will always make it run much better. You'll get a stronger spark too so it may help whem cold.

Edited by Barkychoc on Sunday 30th March 20:58

[MichaelM]

Thanks for all your help. I have already done the plugs, leads, distributor cap and temp sensors. I have ordered a new Ford throttle position sensor and I read the thread on the site so I will check the connections. I was misled by the pics in the handbook and Ford Granada manual that show both AFMs and Lambda sensors being used with the EEC IV.
Thanks again MichaelM

[jimed]

You have already done several of the worth while jobs and the throttle pot is possible but I would have thought a bit unlikely - but have been known to be wrong. As mentioned above have a look at the idle valve; its not a big job at all and you would be surprised how mucky they get inside so in case its sticking a bit .. nothing lost etc ..
Jim

Edited by jimed on Monday 31st March 19:32

Edited by jimed on Monday 31st March 19:37