Affordable Fuel Injection (1 Viewer)

[wngrog]

wngrog, you are probably spot on, but in the past guys who were not using a factory carburetor were not quite so married to the factory air cleaner. I'll be the first to admit times have changed though.

Yeah we all tossed our stock wheels in the garbage too.

OEM look is the trend for sure.

I loved my Downey air cleaner back in the day. Wore it like a badge over the Weber rectangle.

That said with the introduction of the $300 Japanese made City Racer carb I get hives seeing the tiny filters perched on Webers and Hollys and Motorcrafts.

 

[onemanarmy]

I have installed this kit on my 1977 2F, and am now having issues. I've reached out (again) to AFI, and am waiting a call back.

So, when I first went to crank it after install, I got no fuel from the injectors. Could hear fuel pump prime. I tried it about a dozen times while checking all connections. All looked good and voltage was good. So for fun, I tried starting fluid. That got it to start. Injectors then seemed to be operating properly. Then, while dialing in timing, I cranked and drove it roughly 10 times, and all was well. Did not need anymore starting fluid. Then randomly, it wouldn't crank. So I tried starting fluid again...and it fired right up. I let it idle for a while, pulled it in my garage and then it sat for a week. Now, it won't fire again, even with starting fluid and some gas straight into the TBI. Have spark, even tried a new coil. Got the same spark. I have touched nothing in the system.

Anyone have an idea/had this problem?

I hear the fuel pump prime, cracked the fuel line, and gas shoots out when priming, but no fuel comes out of cracked fuel line when cranking engine.

I was thinking bad injectors, but shouldn't it at least try to fire on starting fluid? I'm not quite sure what the computer/injectors are supposed to be doing while cranking. I'm thinking injectors should be spraying fuel while cranking? But they cant, due to no fuel coming out of fuel line while cranking. Pressurized fuel is getting to TBI, and all was running well before this issue. It does not even try to fire, sounds dry, which it is due to no fuel from injectors.

Thanks. Hope to hear from AFI soon.

 

[FJ60Cam]

Do you have the cranking signal wire(starter solenoid wire) hooked up? Can you verify it puts out 12V when you turn the key?

Sounds like that's the issue. Pretty sure that tells the computer to shoot fuel while starting. The priming signal should come from the switched power (which sounds like is working). I'd verify the crank signal as a starting point.

 

[onemanarmy]

I do have it hooked up, and have not touched it since the times it cranked fine. It's hooked to the started solenoid wire, and the starter operates properly, so it's getting 12V.

 

[White Stripe]

Check the 2 pin plug on the ignition module that goes to the distributor magnetic pickup and see if it is kind of loose. I installed a new connector and as new it had excessive play on the female side, pinched the female pins tighter and all is well. Maybe you have the same problem.

I have installed this kit on my 1977 2F, and am now having issues. I've reached out (again) to AFI, and am waiting a call back.

So, when I first went to crank it after install, I got no fuel from the injectors. Could hear fuel pump prime. I tried it about a dozen times while checking all connections. All looked good and voltage was good. So for fun, I tried starting fluid. That got it to start. Injectors then seemed to be operating properly. Then, while dialing in timing, I cranked and drove it roughly 10 times, and all was well. Did not need anymore starting fluid. Then randomly, it wouldn't crank. So I tried starting fluid again...and it fired right up. I let it idle for a while, pulled it in my garage and then it sat for a week. Now, it won't fire again, even with starting fluid and some gas straight into the TBI. Have spark, even tried a new coil. Got the same spark. I have touched nothing in the system.

Anyone have an idea/had this problem?

I hear the fuel pump prime, cracked the fuel line, and gas shoots out when priming, but no fuel comes out of cracked fuel line when cranking engine.

I was thinking bad injectors, but shouldn't it at least try to fire on starting fluid? I'm not quite sure what the computer/injectors are supposed to be doing while cranking. I'm thinking injectors should be spraying fuel while cranking? But they cant, due to no fuel coming out of fuel line while cranking. Pressurized fuel is getting to TBI, and all was running well before this issue. It does not even try to fire, sounds dry, which it is due to no fuel from injectors.

Thanks. Hope to hear from AFI soon.

 

[SteveH]

I hand-crank started my AFI TBI-equipped truck, and just the slow rotation of my hand cranking caused the fuel pump to light up as I rotated the engine. As FJ60Cam said, it sounds like you're not getting fuel while cranking/running.

 

[onemanarmy]

I hand-crank started my AFI TBI-equipped truck, and just the slow rotation of my hand cranking caused the fuel pump to light up as I rotated the engine. As FJ60Cam said, it sounds like you're not getting fuel while cranking/running.

Correct, I'm not getting fuel while cranking the engine.

The fuel pump primes, but no fuel when cranking over.

But that doesn't explain (to me anyway) why it won't fire on starting fluid and/or gas poured in the TBI when cranking

If hand cranking the engine gets the fuel pump going, that takes the 'starter signal' wire out of the equation, correct? What is it using to signal the fuel pump to turn on?

 

[Rusty 72]

From my broken memory. There's a post somewhere on here that another member had issues with the AFI stuff. Was something to do with the distributor and the wires.

 

[SteveH]

In my opinion, you need to call/talk to the AFI guys. They have seen every condition of either component failures or operator-induced miswiring. They were patient and helpful with me. Since I had the ignition on as I was cranking, I suspect the computer saw the distributor turning and said 'hey, he's trying to start this thing' and ran the fuel pump. I just don't know the mechanics of 'why', beyond that.

 

[onemanarmy]

Thanks. I'm awaiting a call back from AFI.

Will be testing voltage at the injectors when cranking, as that is part of the AFI troubleshooting guide.

 

[onemanarmy]

Gonna keep posting here (in the 40/55 section) to get a bit more exposure...

So I've still got a weird issue with my AFI acting up.

Like mentioned before...it ran fine for a week and then nothing. Will not start, even with starting fluid. No fuel from injectors while cranking, fuel pump is not running, except to prime system.

I've talked with Norm at AFI and he's stumped too, especially after yesterday.

So in my quest to continue troubleshooting, Norm suggested I replace the ignition module, which I did. No change.
So, then I wanted to again check for spark, which I'd done before, but just to see. So I have a buddy come over, I take the #3 spark plug out, attach the lead wire, and hold the plug against the engine block (well technically the head)...I see spark when cranking engine. I also smelled fuel, which was odd. Had him crank it over again with the spark plug grounded, and what do you know....fuel is coming out of the injectors. First time I've seen that in a week. So, I had my buddy keep cranking, I saw fuel, and the thing fired up and was running. It ran until he cut it off, about 5 seconds. Sounded fine, except for a missing spark plug.

Excited, I re-installed the spark plug, tried to start it, and no fuel from injectors. Won't fire. So that's weird.

Tried the same routine with #2 spark plug (from front).....same thing....got fuel and it fired up. Re-install plug and again....nothing.

I'm at a loss. Any ideas?

Thanks

 

[SteveH]

Do whatever you need to do to get it running again (if possible), then leave it running and go wiggle every connector and tap every device with a hard object and bang every fitting until it stalls. It seems you have an intermittent problem. I wish I had better advice.

Have you closely inspected (or replaced) the cap and rotor?

 

[White Stripe]

Where is your ignition module located? Pic?

 

[onemanarmy]

It's mounted on the fender below the battery, same place it's always been. Even replaced the guts, no change. Have not inspected cap and rotor (it's new) but will check again.

 

[onemanarmy]

Checked under cap. Rotor and pickup points look ok to me. Did notice some odd corrosion under the cap, to only be 2 weeks old and only driven 10 miles in nice weather.

 

[onemanarmy]

This is how it will run. Have a wire grounding one spark plug to the engine. Fires the injectors and runs. Will not run any other way.

 

[onemanarmy]

Update.....this is not the silver bullet fix. While grounding the spark plug will make the injectors fire, it won't always catch and run. It's intermittent.

Also, I have an aftermarket tach hooked up...and since Ive been having issues, I get no tach movement when cranking. Grounding the spark plug makes the tach move slightly when cranking.

It has to be something in the ignition circuit, but the external grounding of the spark plug making it work has me confused.

 

[wngrog]

Maddening. Start throwing parts at it.

 

[onemanarmy]

Gonna call Norm back tomorrow and see if he'll send me a new distributor. If that doesn't work, I'll see about a new computer. I'm getting fuel with my janky grounding, so guess it has to be spark/ignition issues.

 

[Suprasoup]

Have you measured the gap between the trigger wheel and the VR sensor in your distributor? If it’s too wide, just like points, it won’t trigger the coil to fire. Or cause it to fire intermittently.

Set your engine to TDC and pull the distributor off. Leave all the connections to the distributor on except the cap and spark wires. Pull the ignition coil wire off the distributor and put a spark plug on it and ground it to the engine block. With the truck in the ignition position turn the distributor rotor by hand. You should see a spark for every tooth on the distributor. You should also see the tbi fire at every spark event as well. If it doesn’t fire at every tooth then it could mean your vr sensor is off. Adjust and try again. It could also be the HEI igniter though sounds like you changed that.
Don’t spin it too often or you’ll flood the engine. You can also disable the fuel pump. You’re looking for the tick tick noise as the injectors fire. If you leave the fuel pump on you should see the fuel spray.

What coil are you using? Stock coil?


Hopefully that wasn’t too confusing.

The way these systems work is that the HEI igniter has an input from the distributor. Typically a VR sensor that has a trigger wheel evenly spaced for the number of cylinders. In our case 6 evenly spaced. Every time a tooth passes the VR sensor it causes the igniter to send a signal to the ignition coil to fire. The fuel injection system gets its signal from the coil, typically the (-] side of the coil. Every time the ignition fires so does the fuel injectors.

If your not getting a consistent signal from the vr sensor or the igniter to the ignition coil then you’ll experience inconsistent spark AS well as the injectors not firing or firing randomly.