Just started happening yesterday.

Car was running fine and I had my AFM rebulit by Fuel Injection Corp. I had it rebuilt because I was fiddling around and drive the car before warming it up. At the first stop sign I took off and and had a lean backfire. Car still ran but the A/F mixture was all over the map at any given speed or stoplight.

Anyways, installed the AFM. Started the car up and let it warm up while I wiped the car down. My intention was to warm it up and then set the idle mixture. Car warmed up and the idle mix was a hair off so I didn't touch it.

All of the sudden the car just shuts down! As if I'd turned he keys off! Tried to start it and it was very hard to start. It won't idle, it will just shut down. I can keep the car running if I keep my foot on the accelerator. It is missing badly and running very rich.

If I let it sit for 10-15 minutes and cool down it will fire up just perfectly . It will run fine until it decides to shut down again!

Here's what I've replaced so far with new or spare parts

Coil
Points /condenser
Cap/ rotor
Cleaned and inspected spark plugs (good)
FI dual relay
FI brain
Ohmed out CHTS ( 2400 cold / 50 hot)

What am I missing?

Engine is 1911 with stock L-jet

Maybe you ripped the intake boot.

Can you duplicate these problems everytime you start the car?

Boot is good.

Tim: every time.

The fact that your engine continues to run when depressing the throttle, confirms that your fuel delivery is working fine. But when idling, can you verify that the AFM wiper arm isn't pushing against the fuel contacts, thus turning off your fuel pump?

It's usually the LAST thing you or somone else worked on or changed before the problem started. I would retrace your steps backwards. You may need to re-install the old parts to find the issue.

Only thing changed directly before problem started is he AFM.

The rest was changed to solve problem. One piece at a time.

The last thing I wanted to do was to open the new rebuilt AFM...voiding warranty!

But I'm a rebel and did it anyways...all is good in there. I can move contacts for fuel pump and it will slowly die of fuel starvation.

My problem is as if someone shuts the key off. Instant off!

Just on a whim I pulled the Cylinder head temp sensor while car was running...it died instantly just like my problem.

Even thought it ohm'd out in spec, it could have intermitant problems...right?

Not likely, resistors aren't intermittent. Since this problem is repeatable like clock work, put your voltmeter on (+) side of the ignition coil, and see if the 12vdc drops to 0. when your engine dies.

Just happen as I was reading your response Tim.
Car died. Holding for results. Disregard last numbers posted

11.18 volts at coil when car dies.

So your not losing the spark and your fuel pump is staying active during idle, its saying AFM, well atleast for me it is.
You had your AFM dialed in earlier, can't remember but 6-10 turns? Do you think this rebuilder reset the wheel?

Oh yeah, this is a comeplety different unit.

This means nothing, but I own 2 AFM's. The older AFM is the one I currently use on my car, and the wheel has been adjusted for my 1911. It idles fine, and has pretty good HP, as I set it to run slightly rich. With all of this done, I still get 31 mpg.
The other AFM I own is brand new, well NOS, still has a plastic blue cap on it. For shits and giggles, I decided to try it out. This virgin AFM ran poor on my engine. I could easily keep it running, by reving the engine, but it would die if let to idle. I kinda remember it being like it was a "key off" situation, but its been too long for me to be 100% certain.

Do you have a spare AFM laying around, even if it is broken?

No spare right now...was going to pick one up at the G&R swamped tomorrow.
I want to drive the teener there to verify I was good. Now I'll just buy one and hope!

I'll have to give Fuel Injection Corp. a call on Monday and let them know its not working.
That was $200 not well spent!

With the car running, can you physically move the wiper to a optimum position, with the car at idle. Does it stay running any better with you acting as Mr. AFM?

No. It dies when it thinks it is time to die. Wait 5 minutes after it dies and it will start and run perfectly another 5 minutes. If you try to start it immediately after it dies, it is very hard to start and runs poorly. Misses and runs very rich...most likely due the missing and fuel not being burned.

In the morning it will idle for 15-20 minutes before dying. It seems to be heat related. Something is telling the system to shut down.

I think your right, too much fuel

Sounds like a bad fuel injector. Car runs fine until it warms up then just loses power and dies. Runs fine again once it cools down.

I'm pretty sure these cars will run on 1 or 2 cylinders. I'm not sure a bad injector can cause this.

This engine has 500 miles on it. All injectors are NEW. Not refurbished but NEW. Took a lot of searching but I managed to find 4 of them over a year of parts hoarding.

I had a stuck injector once. White smoke screen out the back, ran like crap all he time. Not the case here.

I know it sounds crazy. Because you have new injectors, it probably isn't your problem. However, a bad injector will cause the car will do exactly what you describe. Perhaps one injector stuck open causes the others not to get sufficient pressure?

I'm searching for some online discussion on the issue because it does sound far fetched.

Hans

I refuse to believe that it can be anything else other than the AFM. We just went thru this engine with a fine tooth comb, a few months ago. Since then, your car was working beautifully, till it backfired a few weeks ago. Your car continued to work, despite the broken AFM. Now, with a new (rebuilt) AFM installed, things aren't the same. This is why I will point my finger to the AFM, till proven otherwise.
You say that the car turns off suddenly, as if someone turns the ignition key to off. Your ignition coil is telling a different story, as its not seeing a drop in voltage. However, we never tested the secondary side of your ignition coil. If you have a timing light, go ahead and connect it to plug 1. Then use some electrical tape, and tape the trigger so it's always on. Now, with your voltmeter, try to probe with your meter lead at the Dual Relay at pin 88b. 88B supply's voltage to your Brain

Now with your engine running, Have the timing light flashing at you, then have your voltmeter closeby. You should see 12vdc with the engine running and a bunch of flashes. When your engine starts to stall, be very observant and see which one you lose. If it is the ignition, you'll notice the loss of flash from the timing light. If your ECU is turning off for whatever reason, you'll lose voltage at pin 88b

Sorry for not responding last night, I was too fixated with the ND game, go Irish!!

My Grandfather and Grandmother are diehard ND fans.
Me...I'm a USC Trojan fan! Fun time with the family at those games.

On to the car.

Went to the G&R swapmeet this morning. I bought a replacement distributor, a pertronix unit, a set of schnorr washers, a new CHT sensor and an AFM (complete with airbox) for $90!!!!

First installed the CHT and started car. Idled for 40 minutes before shutting down.

Installed new AFM and idled for 20 minutes...the old AFM would have quit after 5! So I set the idle mixture and drive around the block...I never quit!!!!

I'll have to verify the fix after a full day of driving, but for now its good!

Best part is, I picked up the AFM $15!!! Opened up the black cover and it is a virgin!! The contacts and board look better than my rebuild! Unbelievable!

Just emailed Fuel Injection Corp. to inform them they sent me a bunk AFM...we'll see how they handle it.

Thanks for the I put Tim!

I gotta find out who I bought that AFM from...I owe him a beer. No it wasn't Gary from Big Bear Ron...he was selling the complete L-jet system...never did ask how much...didn't want to be tempted!

I have a ton of respect for USC, as this is my favorite rivalry games. No matter who is ranked what, it is ALWAYS a very fun game to watch.

Sounds like you got a excellent deal with a working AFM. Towards your rebuilt AFM, I don't think it's broken, it is just not calibrated right. Here is a page from the Ljet manual pertaining to the AFM. Try ohming the temp sensor within the AFM before sending it back.
Click to view attachment

Is that Cap'n Krusty's L-jet PDF? If so would you mind sending it to me at
mikewizblack@gmail.com

Thanks again for all of you L-jet knowledge.

I'll try this out.

Good job, Mike. Good thing you got sick Sunday.

Being that you're a USC fan, I'm not sure if I can support you any longer!

Cough cough

So what was the end result? Did the rebuilder take back the AFM? Is your swap meet AFM working good?

Bad AFM...Fuel Injection Corp. is going to do a UPS call back to pick up defective unit. They say they have to "test" it first. No resolution there.

Swap meet AFM is working sweet! It was actually lean and after I adjusted it, I'm at 13.8 idle, 13.8 cruise and 12.2 WOT! Best numbers yet!