air flow meter

[birminghamtr7]

one thing i have noticed this morning is fuel pump is cutting out after ignition ive traced this to the air flow meter
in side there is an open switch which shoud make as soon as engine start drawing air. mine seems to be not quite making does anyone have a picture of inside of there afm so i can compare. do you think its ok to give it a tweak with pliers. or should i just bypass it...
i think thats enough for know thanks

still smiling [:)]

if you factor in the earth's rotation, we are all speeding

[Marko]

you got the FI manual on the Jclays page.

if i get it right you turn on the contact, fuel pump goes on for couple of seconds and when you start the engine it dies in couple of seconds because of no fuel?



take the multimeter to check if the switch is working. dont bend the metering flap, try to adjust the switch it self.

the worst thing with electronic in these old cars is the electronic issues are so hard to find & fix.

while youre at it check the relays


PS

Good luck , dont let the smoke get out [;)] [:o)][:o)]

[birminghamtr7]

ive got all the manuals, i wasn't goin to bend flap, when i open control box the switch is a long piece of copper strip that makes against a fixed copper post. my solution is i have put a very small cable tie just to keep a bit of tension on switch and it still breaks contact when flap is fully shut off. so it will be safe in advent of accident as is its idea. with fuel cutoff switch as well i should be well safe. but i dont intend on crashing. i will send picture of my mod later

if you factor in the earth's rotation, we are all speeding

[jbsjim]

It sounds like your cold strat injector is providing the initial shot of fuel to the system and then the fuel is being cutoff. At least we know the fuel pump is working. Before trying anything else I would check to see if the air flow meter is functioning at all. Remove the air cleaner cover and filter and jam a screwdriver down the throat of the AFM to prop open the air flap a bit. Turn the key to on and then get down near the fuel pump and see if its working. You should hear it pumping away. If it is then we have to figure out why yours is cutting out. If it isn't pumping then the problem is not the AFM. One step at a time is the only way I can deal with this stuff.
The best Bosch L jetronic diagnostic I have found can be found at www.hiperformance.com/Ljectronic.htm . Its an excellent walk thru the system (46 pages). I've read it at least twice and learn something everytime. There is a picture on page 28 that will interest you. BTW this system is on an Alfa but it is on TR7s as well.
All the best
Jim

[birminghamtr7]

ive fixed it of a fashion. with air cleaner of and top of afm when air flap opens when engine draws air switch doesn't quite make ive put a very small cable tie across switch just to put pressure on copper arm and it works perfect as soon as engine fire flap opens switch takes over the pump running it makes me think there should be some clip or spring in there. in the old loom this may have benn shorted out. see my cable tie holds enough pressure on so when flap closes as shown there is a couple of thou gap enough to shut of pump when engine stops
ive had it running again this afternoon sounds sweet and the tie works well. i'm becoming a tr7 pi guru [:D]



if you factor in the earth's rotation, we are all speeding

[FI Spyder]

Looks like you overhauled your AFM.[:)]

Talked to a Spitfire guy the other day whose brother had a L-jetronic on a Alpha or Fiat with 250,000 trouble free miles. What amazes me is the Fiat/Alpha lasted 250,000 miles.[:D]



TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

[jbsjim]

Looks like you figured it out. In the web article I cited earlier he talks about adjusting the spring tension in the AFM. The "w" shaped wire that's secured with the little bolt is the adjustment. Mark original position, then remove bolt and wire, move gear, put wire back and secure with bolt. Pretty simple. He suggests moving the gear's teeth 5 or 6 teeth counter clockwise to boost performance (might hurt emissions a bit) but in your case maybe that's all you would need to put a little pressure on the copper arm.
Jim

[FI Spyder]

Jim, I just tried to follow your link and I beleive it has changed to the following:

http://www.hiperformancestore.com/Ljetronic.htm

All FI guys should copy contents to their hard drive as it may change in the future or may disappear altogether for what ever reason.



TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

[jbsjim]

Good catch. He has edited his article since I printed mine last year.
Jim