The Classic FJ60 "Stumbling/Hesitating Acceleration/Running Problem

[Landpimp]

Background, had this 86fj60 since 1999(had 92K on in) over the next few years I went thru most everything, tested all the emission stuff, replaced all hoses, carb rebuilt, think i replaced both BVSV, the 60 ran great and I recall it getting like 15mpg. It did gain some weight along the line, 33's ARB, winch, OME ect.........

Over the next decade(for a few reasons) I did not drive the 60 much, few years ago it got an exhaust manifold gasket leak, so I drove it even less. This summer(with 115k now) I found a killer mechanic close to me and had them replace the gasket, we resurfaced the manifolds, no leaks, no backfires runs great.

Still getting 8mpg, power seemed low, when I would let off the gas it felt like there was something holding the motor back.........but it did run will. But, I knew it ran better once, matter of fact I knew it should run as good or better than my 82fj40(same everything but gears), that 40 is peppy, 60 should be so as well, maybe more so as I have 4:11 in the 60.

So for the 1st time in a year I had some free time, so I bypassed the EGR......and took it for a spin...........DAMN!!!!!! its my old 60 again! Feels like I gained 50hp, motor revs freely, let off on the gas and nothing is holding it back. Going up the same hill I would be in 3rd to the top, 4th now with power to spare.

left timing at 7deg. I have no pinging(did not before), no more cab farts, cooling temps are same as before........its just a JOY to drive

it appears I am now getting 15mpg+ and it feels like a dang rocket......

I believe it was the VSV that was failing, but have not ran all the checks in the FSM.....and frankly I am not all that inclined to, no smog checks.

 

[Chocolyle]

I was hoping to help. I recently went through HHHHHH*********LLLLLL with my de-smogged truck. A lot of help here including Slow Left, PinHead and many others.
A: Head gasket replaced with a Reflex suggested by PinHead
B: TrollHole carb, well the second one a least.

Truck runs great!

 

[hank14]

I believe it was the VSV that was failing, but have not ran all the checks in the FSM.....and frankly I am not all that inclined to, no smog checks.[/QUOTE]

Have you looked into a proper desmog Landpimp?

 

[Landpimp]

yes, but done nothing besides remove(3 years ago) the smog pump with a Jim C pulley. I have a spare dizzy and carb I have been planing on sending him, then de-smog.

I believe it was the VSV that was failing, but have not ran all the checks in the FSM.....and frankly I am not all that inclined to, no smog checks.

Have you looked into a proper desmog Landpimp?[/QUOTE]

 

[hank14]

yes, but done nothing besides remove(3 years ago) the smog pump with a Jim C pulley. I have a spare dizzy and carb I have been planing on sending him, then de-smog.

That's about where I am with mine- it runs great now with all smog equipment intact, but I'm not willing to chase down smog equipment issues since it's not required here in Texas either.

 

[87nm60]

I'm late to the thread here. Great stuff! Thanks for everyone contributing to this. Hoping someone can help. I've been searching and searching but haven't found a definitive answer. I have the stumble. When I bought the truck, first thing I noticed was the vacuum hose's were very old and brittle. It's also a clusterf**k under the hood. Hose's disconnected. Mis-routed. Hanging loose. You name it, I've got it. I need to know roughly how much of each size of OEM vacuum hose to order (I believe the 90999-92003 (3mm) will do most of the job. But I think I need some slightly larger diameter hose (5mm) as well as some longer versions of the 90999-92003 (3mm) if I've read the threads correctly). The threads I've found say to order a lot... I'm fine with that, but I don't know what a lot is exactly. With Cruiser Dan now retired, the guys over at American Toyota still honor our discount and they're great to talk with, but they don't have the expertise he had. So they are asking me to find out how much I need of each size and to let them know and they'll get it ordered. I want to stick with OEM parts so I'm not looking for info on any aftermarket hose options. Can anyone help me?

Thanks in advance.

 

[ravenplague]

Hey, check this thread out
Vacuum hoses FJ60

I think i bought 20 feet of the 3 mm from McMaster-carr and could have used more

 

[Output Shaft]

I need to know roughly how much of each size

If you want to get silicon hose at McMaster Carr, see link below:

Vacum hose for a 2f, how much and what size.

 

[87nm60]

Thanks guys. I really want to go OEM Toyota on this hose. Problem is, I've only been able to find threads that talk vaguely about the OEM hose or that suggest McMaster Carr. If I can't get a clear idea of how much OEM to order, I will have to just go with McMaster Carr and call it a day.

 

[Output Shaft]

Measure up what you need. Takes 15 minutes.

This breakdown of Toyota OEM hose gives you the length to price comparisons. 90999-92003 is the most economical way to go. 600mm pieces.

 

[voltaire]

Hey guys my son's 87 fj60 all original smog etc. Would idle great and rev great until trying to accelerate then it would bog down as if fuel starved...If we feathered the pedal it would help a bit. Now a month earlier we put in a new mechanical fuel pump with a near the tank filter and another filter in the engine bay both full of clean fuel and it ran great... So I had to rule out fuel issue... I swapped out the coil! Problem was fixed now it's back to like it was and honestly it has a bit more acceleration feels like a DUI system that I have in my 40 FJPrime. So in our case it was a 22 dollar coil... Figured I'd suggest that here since I didn't see that as a solution God bless

 

[NeverGiveUpYota]

I've wondered on mine w/ the coil. $22 is darn cheap. Where'd you source it?

 

[2mountainfish]

I dealt with all of these problems. Everyone will have a different set of parameters to figure out,but in the end, if you are going to run without the EGR system hooked up, you Will need to get your dizzy re-curved. Even if you don't hear pinging, your combustion temps will be higher and that can lead to serious internal engine problems up to but not limited to blown head gaskets,accelerated valve wear ect.... The stock distributor is designed to increase advance to burn the crappy exhaust gasses pumped back into the combustion chamber. JimC. here on mud does the re-curves. I get no kickback for the endorsement, I just know that it is very important to address the advance curve. Good luck to all. If you take all the advice from this forum and keep plugging away, you will end up with a healthy running 2F, Idid.

 

[voltaire]

I've wondered on mine w/ the coil. $22 is darn cheap. Where'd you source it?

AutoZone and since my post the fj60 is still running strong for my son and he has noticed the acceleration increase by a 3 to 5 % ... He says it's minimal but enough to notice hehe gonna toss in new plugs and a snorkel this weekend his buddies like to mud after it rains here...And since the intake pulls from the driver's side grill not a good idea to keeping there found an El cheapo snorkel on eBay looks to be good quality I'd say up to par with my safari

 

[FJStan]

Apologies for reviving this thread, but just checking in on whether anyone has an explanation for why the jerky hesitation stops once I disconnect the Tach - so smooth.

Although my FJ60 is not desmogged, it pings under load regardless of the tach trick - just throwing it out there to the brain trust here on Mud, which by the way has been an incredible resource to me. Thank you to everyone for their insightful input.

 

[Spike Strip]

TL: DR the rest of the thread, but it has to do with the coil signal to the Vehicle Speed Sensor (a very crude one) in the tach. That signal is used to control the on/off of the Decel Fuel Cut circuit. Explanation in the Emissions FSM.

If you ground the white wire from the ICS you can by-pass that circuit and see if the stumble goes away with tach connected.

 

[mattressking]

TL: DR the rest of the thread, but it has to do with the coil signal to the Vehicle Speed Sensor (a very crude one) in the tach. That signal is used to control the on/off of the Decel Fuel Cut circuit. Explanation in the Emissions FSM.

If you ground the white wire from the ICS you can by-pass that circuit and see if the stumble goes away with tach connected.

I wouldn't doubt if the emissions board is removed and solder points inspected, that you'd find cracks at the plug joints.

 

[Spike Strip]

Yes, but the stumble above 1800 rpm usually means there's wonky sensor input, hence removing the tach input smooths out the stumble. Certainly could be in conjunction with a bad Emissions computer board, though, and with a persistent stumble, must be ruled out.

Again, easiest way is to ground the ICS to carb.

I sure wish I lived in an area where I could remove all of it - Then I'd mail it to Jerry Moonbeam Brown.

 

[FJStan]

Yes, but the stumble above 1800 rpm usually means there's wonky sensor input, hence removing the tach input smooths out the stumble. Certainly could be in conjunction with a bad Emissions computer board, though, and with a persistent stumble, must be ruled out.

Again, easiest way is to ground the ICS to carb.

Thx for the guidance here. If I’m following your logic correctly - regardless of what is going on throughout the various valves and sensors, the ultimate culprit of this classic stumble/hesitation is the Idle Control Solenoid, yes? ...and by keeping it in active mode permanently (by grounding it and thus completing the circuit) the issue goes away? It’s that simple?

 

[NeverGiveUpYota]

Thx for the guidance here. If I’m following your logic correctly - regardless of what is going on throughout the various valves and sensors, the ultimate culprit of this classic stumble/hesitation is the Idle Control Solenoid, yes? ...and by keeping it in active mode permanently (by grounding it and thus completing the circuit) the issue goes away? It’s that simple?

Yes and no. Depends on the type of mudder you talk too. Grounding it is not really considered a permanent fix. Spike is just saying its a way of ruling the computer out. Resolving the primary issue that's causing the ICS (or FCS, one in same) to have its signal be faulty is the permanent fix. Could be the emissions computer solder points have cracks as already mentioned and there are folks that have reflowed the connections w/ new solder. It can be done (your reminding me that I'm going to start a thread on that)... But plenty do just ground the ICS and never think about it again. I had mine grounded but at some point had crazy stumbling with it grounded so I hooked it up the right way and it all went away. When I spoke of it on my thread a person said that maybe being temp unhooked then hooked back up rebooted the computer. Who knows. You can buy a new ICS from CCOT but some will say that the stock one is the best so if you can find a used one on the classified that might be a way to go as well. Have you pulled it and taken a magnifying glass to the o-ring? If its old and degraded or missing as has been noted by others, you can get a new one at an Ace Hardware. They have a great o-ring assortment bin in the plumbing section.