Affordable Fuel Injection (1 Viewer)

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Thanks for all the ideas/help.

Just drove it around the block.

It runs great....even when I had it running originally on the separate coil/ignition module setup, it didn't run this good. Something was wrong from the get go. I do not know what. I now have the HEI setup with the live wires. Purchased Ford straight 6 wires, as to get the straight on, 180* spark plug ends.

Gonna enjoy it while it lasts. Hopefully a long time.
 
Congratulations! You’ve joined the small cult of FJEFI nuts! Keep a spare HEI igniter in the glove box. I’ve found that the original GM ones are bulletproof but the aftermarket ones are not nearly as robust. Cheap insurance.

Don’t forget to check in with an update after you’ve got some mileage on the system.
 
Last edited:
Suprasoup said:
Congratulations! You’ve joined the small cult of FJEFI nuts! Keep a spare HEI igniter in the glove box. I’ve found that the original GM ones are bulletproof but the aftermarket ones are not nearly as robust. Cheap insurance.

Don’t forget to check in with an update after you’ve got some mileage on the system.
Click to expand...
U got a pic of your main spark table if u wouldn't mind posting it up?
 
Suprasoup said:
Congratulations! You’ve joined the small cult of FJEFI nuts! Keep a spare HEI igniter in the glove box. I’ve found that the original GM ones are bulletproof but the aftermarket ones are not nearly as robust. Cheap insurance.

Don’t forget to check in with an update after you’ve got some mileage on the system.
Click to expand...

Thanks for the advice. Will do.

Looking forward to checking mileage, never done that before on this truck. I'm not sure I've ever filled the gas tank all the way full.
 
No updates. I've not changed anything. Drove about 200 miles a few weeks ago, no issues.

It's night and day with mid range power and starting. I had a trollhole carb and desmogged before the AFI, and could never get it dialed in. Had a bad stumble when starting off from a stop. Hot starts were iffy as well.

The only weird thing is that twice it has just randomly shut off while driving. I cut the key off, cut it back on and cranked it up and I kept driving...no further issues. Not repeatable and it drives fine otherwise. Will just be keeping an eye on it. There have been documented issues with the AFI supplied fuel pump, which is what I'm using. Not saying that is the problem, but FYI.

I've been reading about other fuel injection kits that may be a bit better, but are not sold in complete kit form like the AFI is. If I were to do it again, I would investigate those other kits further.
 
Anyone know what a good fuel pump upgrade would be? I have a feeling my fuel pump is wonky. Runs good but starting to grow a small surging effect when idling warm. Also seems to cut out just a bit on acceleration. I need my valves adjusted, so that may have something to do with it.
 
Onemanarmy - thanks for your update.

RE: stalling - I had problems with a fuel selector valve for an aux tank. It was randomly leaking air and giving me low fuel pressure and random stalling. About pulled my hair out troubleshooting this - finally, I accidentally installed a cheap plastic see-through fuel filter ahead of the AFI pump and saw massive air issues.

So, be sure all your supply lines/filters/valves, etc. are rock solid. I may remove my aux. tank, since the switching valves (including a new one) have been unreliable and irritating. Why is something so simple in design so unreliable?

Last weekend, I bumped up my timing from TDC to 'just where the indicator was leaving the window' which should be 5-6 degrees advanced. It seemed to help with a bog off the line problem (where I had to rev it slightly and slip the clutch for a smooth start). I will need to drive it some more to see if there's a downside to this.

My only other complaint is that when I start and drive the truck at 30 degrees F, it runs poorly/rough until the engine warms up considerably and/or it goes into closed-loop mode, at which point it runs fine. I have been in contact w/AFI, but haven't really gotten an answer, other than 'this system is tried and proven...blah...blah...blah..' I wonder if lack of an IAT (intake air temp) sensor doesn't hamper cold weather performance.

I bought a spare fuel pump - this one was recommended on Pirate. Airtex E8094. Check eBay/Amazon/Rock Auto for a good price.
 
I had issues with my AFI install from the get-go (documented here), and spent hours on the phone with Norm?....anyway, he did keep saying how the system was tried and true and 'I shouldn't be having issues'

But I was. He sent me a new style DUI distributor and that fixed everything.

As far as cold temps go....mine will rev pretty high and hunt for a stable RPM until it's fully warm. I'm sure it has to do with only having 1 temp sensor in the thermostat housing. It is a pretty crude setup, but works.

I have no drivability issues now, and am pleased.
 
Your cold weather experience seems normal for these.

It should start much easier than the carb and settle into an idle (even if high), but it still seems to need to warm up before it runs perfectly.
 
The Howell TBI kits come with a Walbro pump, which I’ve had great experiences with. They’re definitely better than the stock AFI units. (AFI is trying to be the lowest priced though)

They also offer a heated O2 option for a few bucks more. This could help get with cold starts. May still need to let the intake warm up for better fuel atomization.
 
FJ60Cam said:
The Howell TBI kits come with a Walbro pump, which I’ve had great experiences with. They’re definitely better than the stock AFI units. (AFI is trying to be the lowest priced though)

They also offer a heated O2 option for a few bucks more. This could help get with cold starts. May still need to let the intake warm up for better fuel atomization.[/QUOTEm]

Part number on the walbro pump?
Click to expand...
 
thecrazygreek said:
Anyone know what a good fuel pump upgrade would be? I have a feeling my fuel pump is wonky. Runs good but starting to grow a small surging effect when idling warm. Also seems to cut out just a bit on acceleration. I need my valves adjusted, so that may have something to do with it.
Click to expand...

This is the fuel pump that came with the Holley Sniper EFI Holley 12-920 80 GPH In-line Universal Electric Fuel Pump So far no issues with it.
JP
 
Your cold weather experience seems normal for these.
It should start much easier than the carb and settle into an idle (even if high), but it still seems to need to warm up before it runs perfectly.

I am trying to 'push the envelope' and reveal any shortcomings in the AFI TBI by running it at low temps, and I did. Broadly speaking, AFI has 'neutered' some of the GM TBI bits (AIT sensor, VSS, etc.) and I think it shows up in poorer performance around the margins of temperature. I wish I could have a non-judgmental discussion about this with AFI.

Mine literally seems to run better on the very hottest days, which is where the carburetor choked the worst, so that's critical - I can do hot restarts in the summer and not have it stall 45 seconds later in the middle of a busy intersection. That is worth its weight in gold, as far as 'not getting creamed and dying in your FJ40'.
 
Good theory. When my road isn't a mud-bog, I'll drive it cold with the advanced timing and report back.
 
Well, with advanced timing (a little) and bumped up idle speed, it stalled after starting (twice) and ran poorly cold. A bit less stumbling under some throttle while cold, but unacceptable. When it was fully hot, the idle was 1800 (!), so I pulled the battery cable for 60 seconds and restarted. Idle was down to 1250 after that. Over Thanksgiving, I will reset the timing to TDC and turn down the idle and see if I can get a baseline of 'running well and idling at 850 when hot' and go from there.

Question: What's the coldest temp anyone on Mud has started their AFI TBI FJ40? At anything close to 30F, mine is not performing well. I can only imagine how bad 15 or 20F might be.
 
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