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914World.com _ 914World Garage _ What is the difference between a

Posted by: jsayre914 Apr 29 2009, 10:20 AM

I was told the 74 and 75 L-jet for a 1.8 motor is different. I was wondering what exactly were the differences, and can you see them just at a glance. If anybody would like to post a picture please do... popcorn[1].gif

Posted by: brant Apr 29 2009, 10:32 AM

I think you mean 1974 vs 1975
no L-jet in 73

Djet was the fuel injection in 1973.. a lot of differences

Posted by: davesprinkle Apr 29 2009, 10:32 AM

QUOTE(jsayre914 @ Apr 29 2009, 09:20 AM)

I was told the 73 and 75 L-jet for a 1.8 motor is different. I was wondering what exactly were the differences, and can you see them just at a glance. If anybody would like to post a picture please do... popcorn[1].gif

'75 and '76 L-jets were different from the earlier years. The major difference was the additional pin on the airflow meter -- early meters had 6 pins and later meters had 7 pins. Of course, the changes aren't limited to the meter -- the wiring harness and the ECU were both changed to support the different meter. So you can't just swap out 1 component; you've got to do all 3 for a backdate or update.

I've run my '74 engine with a -76 L-jet system. Just had to swap out the meter, wiring harness, and ECU.

Posted by: zonedoubt Apr 29 2009, 10:34 AM

QUOTE(jsayre914 @ Apr 29 2009, 09:20 AM)

L-jet is on '74 and '75 1.8L only.

http://www.pelicanparts.com/914/How_to_buy_a_914.htm

Posted by: ArtechnikA Apr 29 2009, 10:54 AM

QUOTE(zonedoubt @ Apr 29 2009, 12:34 PM)

L-jet is on '74 and '75 1.8L only.

...and '76 912E 2,0 ...
true it's not a 914 but it's hard to look at any T-IV engine or injection component in isolation and be able to tell exactly where it belongs.

Posted by: jsayre914 Apr 29 2009, 11:52 AM

QUOTE(brant @ Apr 29 2009, 12:32 PM)

I think you mean 1974 vs 1975
no L-jet in 73

Djet was the fuel injection in 1973.. a lot of differences

edited.

so i need to pull a wire from the airflow and count the pins, that is the only way to tell?

Posted by: davesprinkle Apr 29 2009, 01:44 PM

QUOTE(jsayre914 @ Apr 29 2009, 10:52 AM)

QUOTE(brant @ Apr 29 2009, 12:32 PM)

I think you mean 1974 vs 1975
no L-jet in 73

Djet was the fuel injection in 1973.. a lot of differences

edited.

so i need to pull a wire from the airflow and count the pins, that is the only way to tell?

That's probably the easiest way. Or you could look at the PN on the ECU. Sorry, don't have the numbers handy, but you can search the forum for them.

Posted by: orange914 Apr 29 2009, 10:31 PM

QUOTE(ArtechnikA @ Apr 29 2009, 08:54 AM)

QUOTE(zonedoubt @ Apr 29 2009, 12:34 PM)

L-jet is on '74 and '75 1.8L only.

...and '76 912E 2,0 ...
true it's not a 914 but it's hard to look at any T-IV engine or injection component in isolation and be able to tell exactly where it belongs.

i had a 76 2.0 bus w/ L Jet... if that helps

Posted by: r_towle Apr 30 2009, 05:47 AM

I would suspect the ECU and the AFM are designed in pairs..probably the wiring harness also.

Look at the top of this page...914info...other 914 related sites.
The Ljet bible site is in there as a link.

Should be easy enough to get part numbers...the AFM looks different just at a glance, but you would need to see both together first to get the idea.

Rich

Posted by: ClayPerrine May 1 2009, 06:48 AM

The pin numbers on the air flow meter are the key. 7 pins is a 75. 6 pins is a 74. The wiring harness and ecu are definitely different. If you put a 75 ECU on a 74, you will get rich running.

The difference in the AFM is that in 74 the air temp sensor in it used a common wire with the meter part. In 75 they made them separate.

All of the other parts on the L-Jet will interchange between 74 and 75, but the harness, AFM and ECU have to be from the same year.

And don't even think about using the L-Jet from a 912E. It has different locations for the plugs for the power and ECU, and it only uses one contact in the throttle switch circuit.