FJ62 engine miss at idle (3fe) where to start? (1 Viewer)

[houstonfj40]

Members,

This will be my next project on the 62. I have a slight miss at idle and a little as revs climb to about 1000. Did be the obvious such as wires, plugs, cap and rotor. Injectors were rebuilt about 2/3 yrs ago from PO. Truck is smogged.

Have FSM and just looking for advice of where to start.

Coil, ignighter, egr, value adj..

Searched and read a lot of threads this morning.

Thank you in advance.

Marc

 

[LAMBCRUSHER]

check your tps. adjust the valves. might need to remove to clean the throttle body and iac valve. also check your egr is not sticking...

 

[Michael Hanson]

Hi, I'd replace all the vacuum lines, and there's a lot. Take them off and replace one at a time. Check valve cover gasket or just replace it ,simple and cheap. Mike

 

[houstonfj40]

To baseline my vacuum at idle, is there a "better" hose to pull it from/test? Lines were updated about 2 years ago, after going thru FSM I am thinking a vacuum leak or EGR/Modulator... Will keep all updated.

 

[houstonfj40]

Replaced the vacuum modulator with OEM and the issue seems to be solved. My standing vacuum is good and no hesitation when first driving.

 

[ward93]

can anyone please explain how to actually adjust the TPS. The fsm is very vague

 

[LAMBCRUSHER]

hate to say dig thru the archives, but there are eleventy billion threads on that...use search and start reading. best thing about that is all the stuff you get to learn that you didn't know you needed to...

 

[ward93]

I've searched. and can't find exactly what I need. do you know of any good threads

 

[LAMBCRUSHER]

I'll look in the library and see what looks recommendable...

 

[ward93]

Thank you

 

[ward93]

Any luck? This is so hard to track down. I'll start a thred if I find any or any u find

 

[LAMBCRUSHER]

@ward93 try this...the 22re and 3fe tps have the same calibration process http://www.lcengineering.com/LCTechPages/pdf/Throttle Position Sensor Adjustment.pdf

 

[ward93]

Guys I adjusted my tps and a car that didn't even start and would barely run when it did. Now Is totally normal. Well it's still a little off but I'm pretty sure that's a couple vaccume leaks I found while doing the throttle body. But not no high idol at any temp and it's starting fine with a little help from the accelerator. I didn't believe how much of a difference this could make but now I do. Though I'm missing one of the screws that hold the tps on and need one asap. Anyone know what size they are? Anyway long story short. What my mechanic said was the afm issue is actually the TPS not properly adjusted and in my case missing a screw which let it get loose and explains why my issue got worse over time at at first was intermittent. I want to kill who ever lost the screw in the first place. And I'm wondering if a little lock tite and hex head screws are in order. Hope this helps some one out. But seriously if you have any idol issues check that TPS

 

[EscapeWagon62]

I was experiencing a similar issue, high idle at 1,000 or more plus it would miss/stumble at idle once it warmed up. I also had a temperature guage that never moved above 1/8.
I had a Toyota Master Diagnostic tech look at it and he told me that the engine was warm but thought it was cold. I changed out the temp sensor, temp switch and temp sending unit (all located in the thermostat housing) and adjusted the TPS.
The parts were readily sourced at a local parts store and online and not expensive and getting the correct temperature reading smoothed out the idle. Adjusting the TPS lowered the idle.
For full transparency I had previously reset the TPS to factory spec but had incorrectly set them with feeler gauges on the dash pot screw not the stop screw. Lesson learned.

 

[ward93]

its more luck than science it took me three trys to get it right, and I'm probably gonna do it again cause sometimes it stumbles on the first start or two once it gets warm.

 

[ward93]

hey y'all have any experience with a bumper funnel I think I've got air in my cooling system it tries to get hot while idling, the fan clutch is fine and I've checked litterally everything else. she runs right on while moving, and sitting still if I keep the rpms above a thousand and slip it in to neutral. I know I have a small leak somewhere but I can't quite find track it down yet. but regardless it should still run cool full of coolant.

 

[EscapeWagon62]

No experience with bumper funnels but had to burp my system twice after installing the new thermostat/temp switches since I got a high temp reading after the first attempt. I jacked up the front of the vehicle, removed the radiator cap, put the heater on high with air pointed at DeFrost so I could get the air out of the heater core. I had forgotten to do the high heat/high fan setting/defrost the first time.
Also - if you get some fluctuations in your temp gauge (rapid movement up and down) you probably got some coolant spill on your temp sender gauge electrical connector. Just remove and clean.

 

[LAMBCRUSHER]

check the filler neck for wear where it should seal against the cap. Also, resuspect your fan clutch...a good working fan clutch can actually mask or negate some excessive heat load...

 

[toy_tek]

Posting this for future reference for myself and others. Had similarly described idle miss/stumble issue after warming up, had difficulty adjusting idle RPM to under 900 or 1000, even with the screw all the way in.

Checked most of the items listed in this thread (vacuum leak, EGR operation, EGR modulator & VSV switches, etc).

Found the following:

• PCV valve plugged : cleaned with carb cleaner & compressed air
• Throttle body very caked up with nasty blackness on the back of the butterfly valve.
  • Removed TB
  • removed dash pot assembly
  • marked TPS position (clocked position relative to TB) and removed
  • cleaned TB thoroughly and blew out all ports.
• TPS sensor would not snap back to "home" position easily.
  • Cleaned spring area with electrical cleaner until a clean snap-back occurred.
• Tested TPS per FSM, ok.
• Removed IAC valve, tested per FSM, operation ok, reinstalled.
• Reinstalled TPS.
  • Adjusted per FSM, found new correct position (clocked) differed from previously marked position by approx 1/8"
• Reinstalled dash pot. Couldn't find dash pot adjustment in FSM, so i just left it as it was. Later found info on hood placard, still haven't touched it.
• Cleaned TB-to-manifold mating surfaces thoroughly.
• Installed new Fel-Pro TB gasket #60910 (special order $1.79)
• Reinstalled Throttle body

Started quick, idle immediately much lower than ever before, had to adjust screw up to approx 700rpm. Engine warmed up, no miss or stumble. Have put approx 100 miles on since, considering problem resolved.

{edit Nov 30 2021 - this fixed my issue, no further idle issues after 3 years}

 

[Randy88FJ62]

Nice pdf in the link lambcrusher. Thanks.