Oi who's nicked my airflow meters!!!

[robculm]

Hi folks.
Just bumped into a friendly 350 owner who when having a look over my S hinted that there should be some air flow meters between the filter & plenum chamber. My car is a 91 S3C (C's removed) & apparently the later Granadas didn't have air flow meters, so I'm hoping this is normal.
Any suggestions??????
No taking the P please. I'm new to this, my old spitfire had a carb!!!
Cheers,
Rob

[tvr s4c]

Your friendly 350 owner is correct. The air flow meters should be between the air filter and the hoses connecting to the plenum chamber.

[GreenV8S]

Your friendly 350 owner is incorrect. The later cars do not have air flow meters.

[joospeed]

hmmm ..tvr S4 owner says yay to airflow meters .. did some later cars also have meters then? like peter I though all the later cars were meter-free..

[robculm]

Hmm, still confused so far! Well, I checked a friends K-reg 2.9 Granada & that doesn't have them. There must be some S3C owners who know what they've got there?

[tvrgit]

Peter (GreenV8S) is right - your friend is unfortunately not. S3C does NOT have air flow meters. Categoric and definite. Here's why:

The catalyst engines have lambda sensors in the exhaust manifolds, which detect the air/carbon mix and feed this info back to the ECU, which then adjusts the air/fuel mix accordingly for a given throttle opening and engine load. Hence no need for air flow meters.

[robculm]

That's a relief! Thanks.
Does it matter that the cats have been removed? Do the lambda sensors still work OK without them???

[tvrgit]

yes the lambda sensors only work out the air / hrdrocarbon mix on the "up" side of the cats - taking the cats out means that they still work the same. Some cars have the lambdas downstream of the cats - taking the cats off then screws up the readings.

There is some debate that de-catting means that the engine ecu should be re-mapped. Mine is the same as yours - no cats but otherwise unchanged, and it seems to run ok, having run it for a year. It's just much louder!

[joospeed]

tvrgit said:

Peter (GreenV8S) is right - your friend is unfortunately not. S3C does NOT have air flow meters. Categoric and definite. Here's why: The catalyst engines have lambda sensors in the exhaust manifolds, which detect the air/carbon mix and feed this info back to the ECU, which then adjusts the air/fuel mix accordingly for a given throttle opening and engine load. Hence no need for air flow meters.

unfortunately that's not the reason. Lambda sensors work nowhere near fast enough to be the govenor of the fuelling .. all they can do is send a signal based on what's already happened so the ecu can trim the fuelling for the next events .. the ecu still needs a firaly accurate map already in it, the lambdas are only trim devices. The non air flow cars have MAP sensors to sense load for fuelling and ignition.

[tvrgit]

And there was me trying to keep it simple just to highlight the difference...

[chin up]

My S3C has no airflow meters. I had to work quite hard to convince a local garage that this was deliberate (phone calls to factory etc...) Won't go back there again. This guy just refused to accept that it was meant to be like that.

From the chap in the factory the remapped ecu can lead to our TP's burning out more readily than in other S's, apparently. (runs for cover) Please don't shoot the messenger....saying that, I've had no trouble with mine....

Cheers, chin up

[robculm]

Thank's for all your comments.
She's having some general running problems, especially at low revs & difficult to start. Partly why I was panicking a bit about the prospect of not having them when I should! I'm planning to get hold of a multimeter & check the sensors / throttle pot etc this weekend. Hopefully I can find something there.
Cheers, Rob.