HELP! tiny surging at idle and random throttle issues (1 Viewer)

[bleenike3]

Hi everyone,

Been dealing with 2 intermittent problems with my 1995 FJ80

1) a very small "surging" feeling of at idle and I can't figure out what's causing it. Sometimes there will be a tiny surge and it will struggle to keep rpm up and will shake or car will die at a stop -

2) When driving, at constant RPM - when I'm holding pedal down consistently the engine will also misfire or feels like it cuts out of power for a split second before "catching power" again if I slam the pedal down. Also the accelerator tachometer will lag for a few seconds before starting to move when accelerating (throttle power cuts out briefly at 0:07 in this video) -

What I've done so far to try to fix this issue:
- all vacuum hoses replaced
- throttle position sensor replaced (89452-22090)
- idle air control valve cleaned, not replaced (22270-66010)
- mass air flow sensor bought, not yet replaced (22250-66050)

Any ideas of what I should try doing next to solve? Thank you!

Thanks all

 

[voodu3]

it’s hard to tell from the videos but I would start with the easy stuff first.
Fusible link condition (just replace it so you know it’s good)
Battery cables and terminals: no corrosion and solid connections at power and grounds
Throttle cable smooth movement of cable inside sheath.

 

[bleenike3]

Thanks voodu!

1) I did replace the fusible link a few days ago...
2) I did look at and adjust/clean battery cables and terminals
3) Will take a look at throttle cable - i'm a bit suspicious of this but not sure how to adjust. Will do some research on this.

Note - yeah, from the video it's a bit hard to see ... the surging is SUPER subtle... but you can tell the idle starts to struggle and slightly loses RPM

 

[bleenike3]

Quick update -

Just replaced the MAF and tightened the throttle cables based on this post - 80-series Throttle Adjustment - Land Cruiser Tech from IH8MUD.com - https://www.ih8mud.com/tech/80throttle.php

Didn't 100% fix the idle issue but when I was tinkering around looking at the RPM after the update above I did notice that my RPM would dip -100 RPM whenever I used any electronics... e.g. when all windows were depressed (up or down) I would lose 100 RPM while the windows were engaged... maybe wiring harness issue?

 

[voodu3]

Take a look at the harness on the top of the engine by the firewall. Try moving it around while the engine is running see if any thing changes. There maybe a short in there. Also if you’re losing rpm under electrical load it could be your alternator.

 

[mjosoba]

Check grounds too.

Long shot, but have you messed with the distributor at all? I had just down my HG and a million other things and it would act this way occasionally. I was worried the HG had gone again. But the bolt that hold down the dizzy was barely loose and it had moved. Timing was off by a decent amount.

 

[bleenike3]

I did inspect the wiring harness... some wires were exposed but it didn't look frayed/cut or damaged... nothing happened when i pushed and shoved it around while the car was on so I just covered it with heat protective wrap.

I also added a ground wire to the fender wall from the negative terminal on the battery - this was not connected and seems to have helped.

Haven't messed with distributor at all.

 

[bleenike3]

FIXED

issue was failing distributor