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Injection mixture control
Mark Allanson - 12/8/10 at 02:23 PM

I have a curious problem with my car. Occasionally it cuts out, but only when you slam the throttle down, if you squeeze the pedal, it doesn't happen, you can 'start' the engine again by simply easing off and then squeezing the pedal down again. If you keep the pedal down while it is cutting out, it jolts back in and out until you ease back again.

The car is completely driveable except when you need the power the most, you get none!

I think it may the the air mass meter door over opening and not giving any signal to the ECU. If this is the case an increase in mixture may help as this is done by altering the throw of the door.

Does anyone:-

1, know which way the screw is turned to enriched the mixture (presently 0.5% which is low for a non cat car) http://board.marlincrawler.com/temp/maf/maf_maf.jpg

2, have any injection parts (1989 2.0i Pinto Sierra) they don't want in exchange for beer tokens

3, have any other ideas

[Edited on 12/8/10 by Mark Allanson]

Bluemoon - 12/8/10 at 03:01 PM

Acceleration fueling not rich enough??

phoenix70 - 12/8/10 at 03:41 PM

What EFI parts are you looking for?

I've just stripped the standard efi off my car (went Megasquirt) so I should have all the parts lying around.

Cheers

Scott

Mark Allanson - 12/8/10 at 03:45 PM

quote:
Originally posted by Bluemoon
Acceleration fueling not rich enough??


Thats why I want to enrichen to see if it makes any difference, I don't have a CO meter handy until I get back to work, so I wanted to apply a 1/4 turn in the right direction - but I don't know which direction!

Mark Allanson - 12/8/10 at 03:47 PM

quote:
Originally posted by phoenix70
What EFI parts are you looking for?

I've just stripped the standard efi off my car (went Megasquirt) so I should have all the parts lying around.

Cheers

Scott


I will take the lot if you don't want it - the easiest diagnostic tool is replace and see if it makes any difference!

britishtrident - 12/8/10 at 04:05 PM

It is not uknown for the fmetering lap hinge to stick -----

RazMan - 12/8/10 at 05:32 PM

TPS a bit noisy?

Mark Allanson - 12/8/10 at 06:23 PM

quote:
Originally posted by RazMan
TPS a bit noisy?


Is that a replacement at worst or a squirt of WD40 at best?

MakeEverything - 12/8/10 at 07:07 PM

quote:
Originally posted by Mark Allanson
quote:
Originally posted by RazMan
TPS a bit noisy?


Is that a replacement at worst or a squirt of WD40 at best?


No, its making sure your TPS cable is screened and grounded to the same earth at both ends.

Mark Allanson - 12/8/10 at 07:29 PM

I am running almost standard Ford injection so all the cables were made by Uncle Henry

RazMan - 12/8/10 at 07:31 PM

quote:
Originally posted by MakeEverything
No, its making sure your TPS cable is screened and grounded to the same earth at both ends.


.... or it could just be knackered

Mark Allanson - 12/8/10 at 07:33 PM

The system looks like this

Modified Injection
Modified Injection

RichardK - 12/8/10 at 08:31 PM

I thought screened cable should only be grounded at 1 end ??

Cheers

Rich

Mark Allanson - 12/8/10 at 09:05 PM

Do I have a screened cable on a standard setup?

Mark Allanson - 13/8/10 at 12:21 PM

It only seems to happen higher up in the rev range, when the air demand is higher which points more towards the air mass meter - any thoughts?

RichardK - 13/8/10 at 04:00 PM

My missus had a KA that would start up and idle everytime but unless you went very slowly with the throttle it would stall, sounds a bit like yours but worse and that was the air flow meter. I just unplugged it and that let me drive it home ok, maybe unplug yours to test, it wont run right but it should confirm if its at fault or not, apparently if the ecu doesn't get a signal from it, it just uses default settings a bit like limp home on ignition.

Cheers

Rich

Mark Allanson - 13/8/10 at 04:53 PM

Rich - Ideal I will give it a try.