Source For Rebuilding the AFM?

[RRoller123]

I tried contacting Fuel Injection Corp; which was mentioned here as having been successfully used for an AFM rebuild, but they didn't answer my email. Doesn't instill confidence. What sources have you folks tried for rebuild of your AFM? I assume there is more than just the one. It is the last piece of my FI puzzle to sort out I think. Thanks.

Pete

[tima01864]

Only one i found online http://bavrest.com/about-us.html

[davidbruce]

Or you could get one from AR
[quotehttps://autoricambi.us/remanufactured-bosch-air-flow-meter-1980-85//quote]

[RRoller123]

thanks fellows, I will check it out.

[RRoller123]

Be advised that Fuel Injection Corp, although not answering emails or website inquiries, immediately answered the telephone. LOL.

I am sending the AFM out today. ~250 bucks, ~5 days turnaround. Full refurbishment and calibration. Replacement of the TFR board if necessary.

BTW, I have my fuel pump activation arm bent out of the way, as I keep the fuel pump powered on when the ignition is on, and use an inertial shutoff switch for safety in the case of an accident. If you do this (common mod), don't forget to add a note with the unit telling them NOT to straighten the arm back out.

Pete

[tima01864]

Curious, My fuel pump is activated with the ignition key. Probably hacked before the previous owner replaced the AFM, The seal on the new AFM is intact I have doubts the AFM was modified to work with this hack?
My next task is to wire the fuel pump back as intended, Activated with the AFM flap. Looks like a green wire was made hot with the ignition.

[RRoller123]

The AFM MUST be modified to do this Fuel Pump mod, the arm at the right must be bent slightly CCW so that it does not make contact during the off position. Doing this eliminates the half of the dual relay that powers the Fuel Pump. The pump is then directly wired to an ignition "ON" source. BUT MAKE SURE that an inertial safety shutoff switch is also used in the event of an accident.

[tima01864]

I dont know how it was done on my car, The AFM cover was never opened. I think the PO just wired it hot

[RRoller123]

May just have disabled or removed the pump side of the dual relay.

[RRoller123]

AFM came back yesterday from Fuel Injection Corp; Tracy CA. Will unbox it and see if it makes any difference, probably later today. The lady that called to tell me it was coming laughed a bit when I asked what it needed. Said the core was quite a mess, but they did everything they needed to bring it back into spec, at the quoted price. ($249 plus $14 return shipping). It used to squeak and the door still dragged a little bit. I had sanded the core to eliminate the squeak a few years ago, but I think the axis of the swing arm was pretty far gone, and the door started to sag once again, causing a squeak as it opened and closed. It was time for a rebuild. The TFR have dual tracks (one from my adjustment of the swing arm, one from its previous life). If they sealed the top (I sent it out with the top off) I will NOT open it up at this time. I also sent it out missing the security plug/button that stops access to the bypass adjustment screw, will be interesting to see if they replaced it, I expect that they did.

[18Fiatsandcounting]

Good to know Pete, and I noticed that Fuel Injection Corp. is about 25 minutes from where I live. However, given greater Bay Area traffic these days, perhaps just a tad more.

Anyway, let us know how it works out.

-Bryan

[RRoller123]

The AFM is installed, but I am charging my battery, so while that is going on....

OK, so first off, it came back extremely well packaged, and delivered by FedEx. They used EPS foam inside the box.







It was repainted a nice grey that matches most else on the engine, and the top is sealed on. I had sent a note with the unit, asking them to NOT straighten out the arm that connects the contact for the Fuel Pump Relay, as I run the pump all the time and use an inertial safety switch. I will know whether they followed this request when I turn on the ignition. If I don't hear the pump, they straightened it, if I do hear the pump, they complied.



The bottom was obviously removed and every possible air entry point resealed.



Hard to see in this pic, but they replaced the slotted screw adjustment for air bypass with an Allen bolt, which I WILL NOT TOUCH, hahahah! BUT there is no cap to keep someone from going in there and fiddling with it.



So far so good, I will know in a while if it makes a difference in how the car runs, BUT given that I suspect a possible Fuel Pressure Regulation issue, and a CAM issue, I will not be disappointed if it makes only a slight or no initial improvement, as I have more diagnosis and repair/refurbishment/upgrades to do.

Pete

[RRoller123]

OK! So the rebuilt AFM has made a marginal improvement in the running of the engine, as expected, yet I still have this idle speed variation, it runs up and down, stumbles unexpectedly, recovers, etc. This video is with the engine warm, it is far worse with the engine cold, and I need to keep fluttering the accelerator to keep it running until it warms up. In the video, if you turn up the volume, you can hear the engine speed variations. Any ideas? Fuel Pressure Regulator is next. I have a new one, and it may go in as early as tomorrow. Have Registry business to attend to. New toy is coming.

Pete



Why won't the video show? Only 30 seconds long. OK, so here is the direct IMGUR link: It is the very first one in my collection.

https://rroller123.imgur.com/all#1

Why is there no volume??? This is so irritating, unbelievable that after about 40+ years, we still have to go through this nonsense for something that should work like a toaster.

[rridge]

Idle speed variation and stumbles can be caused by a TPS that is mis-adjusted or simply not working. The TPS signals the ECU when the throttle fully closes. If the microswitch inside the TPS does not function, the ECU continues to fiddle with the mixture using the oxygen sensor input. That input is unstable at idle speed.

[RRoller123]

Yep, that has been carefully checked. Thanks though, it can screw up the ECU, and then the O2 sensor starts trying to readjust. Another thing is if the throttle plate is too far closed, and the idle is relying upon the bypass screw. We saw this last weekend while playing around with it, it tends to surge, then the O2 sensor corrects, and it backs off. Odd behavior. I try to set the fully closed throttle plate so there is about 0.010" of gap at the bottom, this seems to work pretty well.