Air fuel ratio Ljet Options

[StarBear]

Rich, I apologize if I came across as admonishing you. My suggestion is not to start from Zero, but to eliminate a variable in your troubleshooting. Using a known good AFM would eliminate that from the items you need to check. Do you have someone close to you with a running L-Jet car you could borrow the AFM from for troubleshooting purposes?
Clay

No worries. (IMG:style_emoticons/default/grouphug.gif) I have several but all have been opened.
As it happens our old friend Troy @Messix dropped by out the blue the other day & while he's been spending all of his free automotive time on his Jeep, he still has his 914 that may be pressed into this effort. Not sure when the last time he ran it, but assures me it does (IMG:style_emoticons/default/biggrin.gif)
But hold on ... it just so happens I have a complete 912E motor I got from Ralph Meaney's shop after he passed. & it has a AFM on it that looks like its never been touched.
More to come..

There were two different air flow meters. 74s used a 6 pin meter, and 75 used a 7pin. I think the 912E used a 7 pin but I am not sure. So make sure the pin count is the same.

Clay

IIRC, yes, the 912E used a 7-pin AFM. In 912E LJet guide on Jeff B’s site.

[nihil44]

I have been outed by @wonkipop . I have been loitering in the shadows observing but I've had very little to offer in the foregoing discussions.
The specs on my project car are as follows
’73 2.0 DJet converted to LJet. 3 stud intake runners cut and welded to line up with L Jet plenum
’75 AFM – rebuilt by someone in California. Looks pristine inside
’75 7 pin ECU
No decel valve
FJ6 Standard Motor Products injectors
123 Distributor
Rebuilt throttle body by Phil Eslin
Current ailments – long crank to start and stumbles to stalling under load. Strong of petrol which seems to emanate from engine bay.
Booked into mechanic who has dyno and exhaust gas analyser. I am getting nowhere with my fiddling

Just some observations following which may be of use or interest

I made a tab to hold down cover on AFM for ease of observation only - @ClayPerrine . Hate the idea of silicone sealing


Inside ’75 7 pin AFM. Note counterweight on wiper and dob of silicone on top of black plastic cog indicating absence of tampering - @ClayPerrine . Looks factory quality. 2 white wires coming from temp sensor 1


Inside Kombi 7 pin. Small or no counterweight


Inside 6 pin ’74. Swapped out because of poor function. Note presence of counterweight and no silicone on adjustment screw and evidence of galling on adjustment screw from prior monkeying. No white wires coming from position of temp sensor 1


Note comparative size of intakes. ’74 has plastic tit in intake which is embossed with ‘1’ but no wires leading from it. Same position on Kombi intake is temp sensor ‘1’ – see wire connections

I have fitted the Kombi AFM to the car and it starts and runs but have not driven it.

[ClayPerrine]

I don't understand why you would have to "cut and weld" the intake runners. A little tweaking side to side and the 2.0 Runners fit the 1.8 intake plenum fine. Yes, they are a little short, but that can be compensated for.

I wouldn't mess with using a Kombi AFM on a 914. Unlike current fuel injection, the parts on the early systems like the 914 L-Jet are matched and don't really work well when mismatched.

Good luck.

Clay

[nihil44]

Clay,

I was just having a play with the Kombi AFM just for interest. I am not intending to deviate from the '75 AFM ECU combination.

[wonkipop]

thanks for the images @nihil44

great to be able to see inside without having to tear mine open.
which i don't want to do since it ain't broke. (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)
interesting too to see the differences and evolution of the equipment.

[Van B]

That ‘74 6 pin doesn’t look like either of mine.

[nihil44]

Apologies to the group for posting photos of what I believed to be the AFM from a 74. @Van B alerted me to the possibility that the photos were incorrect. I believed it to be a genuine 74 AFM as that was the AFM that came on the car when I got it.
I popped the top of the AFM which is on the car and indeed it is quite different inside. I don't know where the other AFM came from as the black plastic cap bearing the part number has been lost. Updated photos below. There are 2 black wires coming from the position of temp sensor ‘1’
I looked up PET and the change over point for the different AFM and ECU is the same – engine # ECO 037 551. 6 to 7 pin change over. No surprise there. Part # on this AFM is correct for '74