EFI issue for discussion

[EFI Guy]

I would do a KOER test while your problem is present. By this I mean do not shut off the key when it acts weird, test it right then.
My first instinct would be crud in the tank causing a restriction and turning off releases it, but if pressure is good that is ruled out.
So if it's in some sort of limp mode then the KOER test should point it out.
I do have a video about the caps on my Youtube channel, but typically you will go very rich when that happens.

 

[73azbronco]

I am going to inspect the caps. Since that is the easiest to do.

I don't have any other OEM computers to test against.

TFI issues, I do have a spare distributor that I know works that I can test against as well.


Thanks for this info.

isnt it easier to check fuel pressure while you drive around?

 

[pcf_mark]

I had a TFI distributor slowly flake out it would stutter and drop rpm. Then one day it just died.

If you decide to go back to MegaSquirt hit me up I have had it running on my rig forever trouble free. It controls my 5.0 and 4R70W and I drive a few thousand miles a year from 100 degree days in summer to 0 degrees in the snow. The only time it let me down I had a bunch of snow get under hood and short out my relay block. I never liked the auto tune I just had someone drive around while I made adjustments from the passenger seat. Power pulls I used my wideband O2 to and a data log (this was tedious) to make adjustments. My tune is super conservative.

 

[sanndmann3]

I would have similar issues when I was getting in the throttle and the engine would die. Fuel pressure would flat line.
Replaced the stock fuel pressure regulator with performance unit and the problem went away...

 

[73azbronco]

Fuel pressure, step one in EFI problem solving.

 

[Sporto]

Fuel pressure, step one in EFI problem solving.

I have a gauge on the rail. I will stop and check it when it happens again. Has not occurred in the last few weeks of driving. So it is a mystery for sure.

 

[Sporto]

I had a TFI distributor slowly flake out it would stutter and drop rpm. Then one day it just died.

If you decide to go back to MegaSquirt hit me up I have had it running on my rig forever trouble free. It controls my 5.0 and 4R70W and I drive a few thousand miles a year from 100 degree days in summer to 0 degrees in the snow. The only time it let me down I had a bunch of snow get under hood and short out my relay block. I never liked the auto tune I just had someone drive around while I made adjustments from the passenger seat. Power pulls I used my wideband O2 to and a data log (this was tedious) to make adjustments. My tune is super conservative.

This is great info! I have not switched back to the Megasquirt setup yet, but I am planning on trying it out on the drive to Super Cel in Tennessee in a few months. I'd be interested in seeing your tune. How modified is your engine? I have a basic 302 with a mild Performer cam. I may reach out once I get this back on and running. Thanks!

I would have similar issues when I was getting in the throttle and the engine would die. Fuel pressure would flat line.
Replaced the stock fuel pressure regulator with performance unit and the problem went away...

Was there any specs on the performance one, I may take a look at that? I had the fuel cut out issue that happened first, and it left me by the side of the road, then I replaced the old FPR with a stock one from Amazon. Now I have this problem where it just starts running lean, with no warning., however it does not cut out anymore.