1fzfe stalling during steep ascents (3 Viewers)

[William839]

Exactly as the title says, I still have not been able to figure out WHY my 1fzfe 196k miles , very well maintained stalls during steep ascents , otherwise the motor is absolutely solid , in fact sometimes it’s difficult to recreate. I’ve done all usual maintenance including fuel filter , charcoal canister , fuel pump , pcv valve , etc… any pointers would help out , I’ve tried wiggling the harness near the EGR with no avail .. stumped .. I heard some people say it’s “normal” when you’re attempting a steep hill and let go of the throttle but I don’t think I ever let go of throttle when wheeling .

 

[John McVicker]

WAG…is your idle too slow…too low?

 

[William839]

WAG…is your idle too slow…too low?

Noo , around 2000 rpm

 

[John McVicker]

Never mind, your issue is with ascents…I was thinking descents

 

[LandLocked93]

Exactly as the title says, I still have not been able to figure out WHY my 1fzfe 196k miles , very well maintained stalls during steep ascents , otherwise the motor is absolutely solid , in fact sometimes it’s difficult to recreate. I’ve done all usual maintenance including fuel filter , charcoal canister , fuel pump , pcv valve , etc… any pointers would help out , I’ve tried wiggling the harness near the EGR with no avail .. stumped .. I heard some people say it’s “normal” when you’re attempting a steep hill and let go of the throttle but I don’t think I ever let go of throttle when wheeling .

I misread the post too thinking it said 'descent'.
At any rate, is it difficult to restart after it stalls?
Can you restart while still on the ascent or do you have to roll back to level ground to restart?
Are you caning it up the hill or doesn't matter?
As far as being 'normal', I've never had that issue in my '93.
Have had a couple 'brown outs' going down hill, but we're talking less than half a second hiccup, then all returns to normal.
I liken it to a horses sneeze. lol

 

[William839]

I misread the post too thinking it said 'descent'.
At any rate, is it difficult to restart after it stalls?
Can you restart while still on the ascent or do you have to roll back to level ground to restart?
Are you caning it up the hill or doesn't matter?
As far as being 'normal', I've never had that issue in my '93.
Have had a couple 'brown outs' going down hill, but we're talking less than half a second hiccup, then all returns to normal.
I liken it to a horses sneeze. lol

Starts right away. Haven’t tried to start it on the hills usual my brakes can’t hold the heavy 80 up

 

[Funner]

Battery stability an issue? Fusible links?

 

[PeterTheBeater]

Have you tried the fuel regulator? I feel like it staling would be something fuel related. Does it matter how much gas is in it? Does it stall when you’re in a certain gear or the rpm’s go low?
For example, will you stall in 2nd?

 

[William839]

Battery stability an issue? Fusible links?

Both new .

 

[William839]

Have you tried the fuel regulator? I feel like it staling would be something fuel related. Does it matter how much gas is in it? Does it stall when you’re in a certain gear or the rpm’s go low?
For example, will you stall in 2nd?

That’s my next step I suppose , throw a fuel regulator at it , doesn’t matter how much fuel , and no rpm drop , sudden stall no matter what , only can be recreated at steep angles

 

[jonheld]

Noo , around 2000 rpm

Hold on a sec.
Normal idle RPM should be 650 at normal operating temperature.
If your idle speed is 2K, something is very wrong.
Likely the throttle cable is misadjusted. There should be slack in the throttle cable at idle position and the throttle plate should be resting on the end stop.

Your brakes should be able to hold the truck on an incline. I'm thinking you have several issues going on with your truck.

 

[William839]

Hold on a sec.
Normal idle RPM should be 650 at normal operating temperature.
If your idle speed is 2K, something is very wrong.
Likely the throttle cable is misadjusted. There should be slack in the throttle cable at idle position and the throttle plate should be resting on the end stop.

I meant during climbs, if I’m climbing something slowly 2-3k RPM Is when it stalls.

 

[jonheld]

I meant during climbs, if I’m climbing something slowly 2-3k RPM Is when it stalls.

When it stalls, does it cut off instantly like you turned the ignition off, or does it slowly die?

 

[William839]

When it stalls, does it cut off instantly like you turned the ignition off, or does it slowly die?

Instantly .

 

[jonheld]

Instantly .

Then it's EFI/electrical related. A fuel issue would sputter and stall as the motor starves.

 

[William839]

Then it's EFI/electrical related. A fuel issue would sputter and stall as the motor starves.

Even if the fuel regulator is not operating correctly ?

 

[jonheld]

Instantly .

When it stalls, is the CEL illuminated

Even if the fuel regulator is not operating correctly ?

I'm going to say yes. Again, when a motor is starved for fuel, it doesn't just stop instantly.

 

[William839]

When it stalls, is the CEL illuminated

I'm going to say yes. Again, when a motor is starved for fuel, it doesn't just stop instantly.

Yes it does but no codes , one I start the rig it goes away (as it should )

 

[PeterTheBeater]

Have you checked the timing & timing advance?

 

[jonheld]

Yes it does but no codes , one I start the rig it goes away (as it should )

Personally, I think you have a faulty connection in the engine bay. I'm going to suggest some "percussive diagnostics".
When under load, the engine is shifting around on the mounts. More so when climbing a steep grade and bouncing on rocks.
I would start with some low hanging fruit, like the EFI relay socket, EFI fuse socket, connector EB1 next to the power steering reservoir.
Any one of these would cause an "instant off" issue.
Fusible links are also a prime suspect.
I understand that they have been changed, but they are subject to vibration and fatigue and you can't check them with your eyeballs. While the ring terminals should be secure, the mating grey connector off the pink link is suspect. That link provides +12 to all injectors, ignition coil, and igniter.