TS86

Need some help here....

I have a 86' 4runner and the engine has jerked/sputtered a few times the past week while driving.. Let me explain:
I will be driving down the highway and the engine will suddenly jerk (seem like its about to stall) and then it runs fine again. Its the same sensation as when you are accelerating and your foot slips off the gas.
Any Ideas what would be causing this?
It hasn't happened that much in the past but recently has become more frequent. It seems to most often occur at highway speeds although I have noticed it at lower speeds as well.

Any ideas what could be causing this?
As always any help is much appreciated.
Thanks.

Duffdog

yes... mine did the same thing 88'

first I replaced the TPS, that didnt do anything. Changed fluids...still nothing. Then after checking the electrical wiring harness for intermittent shorts, I replaced the cam because the intake cam on #4 was worn down. No more sputtering--and its faster too. I guess one of the cylinders was interfering with the MAP sensor and throwing off the reading--when it got too out of whack, the ECU cut spark.

T

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TS86

Thanks for the help....
I forgot to mention it seems to be related to the amount of gas in my tank..
It seems to usually occur when the gas tank is under half full... Not sure if this could be related or merely a coincidence.

midiwall

Crud in the tank that's blocking the fuel pickup?

Tacoma Dude

Maybe you need a new fuel filter? I changed mine out of my '86 and immediately felt a difference.

02SE

I see you're in Canada, probably pretty cold right now.

I would bet you have water in the gas tank freezing. The water accumulates inside the tank due to condensation. It becomes a problem in below freezing temperatures, when the water freezes.

Keeping the tank as full as possible, will lessen the room inside the tank for condensation to form.

Dump some gas line anti-freeze in the tank. If the fuel filter is old, it wouldn't hurt to replace that either.

SoCal4Running

You didnt say or not but does it do it in the rain. I had a 89 that did that exact thing only in the rain; water in the distributor.

Any check engine light?

TS86

Nope... It's not related to rain. Only snow here at this time of the year.
But either way it has happened on days without moisture.

Erich_870

It sounds to me like your fuel injectors are clogged/fowled. My rig will occasionally buck like a bronco when I partially reduce the pressure on my gas pedal. Try running a bottle of Sea Foam in your tank when you fill up again. It's just a band-aid for my rig. I know I need to have my injectors rebuilt or replaced, but I don't have the time or the cash, so I just do the Sea Foam in the tank once a month.

Erich

Tiger Paw

I have an 89 4cyl that was doing the same thing. Turned out the insulation on the spark plug wires was wearing thin. I got a little "pop" when I put my hand too close to them while the engine was running. I changed them out and it took care of the problem. Good luck!

Swede

Try these options before you do anything else #1 - For water in the gas, dump some Methyl Hydrate in the tank and then fill it up. And
#2 - Replace the fuel filter. These are cheap fixes and you can go from there.

epic37311

mine does it sometimes. Its carberated. I am pretty sure its bad gas. mine feels like its hitting on 3 cylinders. Then fill her up with diff gas and its fine.

TS86

Thanks for all the help..
I haven't done anything to the truck yet as I was keeping the gas tank over half full all the time and wasn't noticing any problems.
That is until this last weekend. It started sputtering a fair amount at 3/4 tank.
I am now down to 1/4 tank and its sputtering a lot and my power has dropped considerably.

Any more ideas before I try to get it fixed this weekend?
Thanks.

midiwall

I think Swede's got it nailed - fuel filter.

tmclancey

(1985 toyota pickup 5 speed 2 wheel drive) I have been experiencing the same symptoms of jerking while traveling at constant speeds and a jerk or jolt while pressing the accelerator. I put the truck on jack stands and put the truck in third gear and while maintaining a constant speed the rear end started kicking down. so i figured it must be bad gears. I swapped rear ends from a truck at the junk yard and still had the same problem of the jerking.... i was convinced the problem was still in the rear end and that i got a bad rear end from the junk yard so i did the same test by putting the truck on jack stands, again the rear end was kicking down towards the ground. So i opened the differential that was originally in the truck to check it out and the spider gears had a lot of play. out of curiosity i wanted to know if it was my problem so i welded the spider gears to keep everything tight and eliminate the free play. I did this just to test since now i had an extra differential. after i welded the the gears i put the welded third member in the truck and my problem was solved. The free play in the spider gears were causing the jerking. now the only thing is it is a true 2 wheel drive truck and one tire drags while making turns....until i find new spider gears to rebuild the other third member i will tolerate the dragging. If anyone knows where i can get new spider gears please let me know because i can not find any place that has spider gear kits for a 1985 toyota pickup.

cbh148

found this old thread from googling "22re constant speed jerk" in an attempt to figure out why my '94 Xtracab 4x4 5-speed acts crazy when out on the road. it doesn't do it all the time, and i'm not sure if it's more/less likely to do it depending on having a lot of gas in the tank or not, but i wanna figure this out because it's super annoying!

hopefully it doesn't require welding the rear diff or anything because i've been riding around with a welded diff in my 240sx for years and the only reason i can tolerate it there is because that car drifts so well that it's worth it. would love to find a solution for this!

tmclancey

[QUOTE=cbh148;52340915]found this old thread from googling "22re constant speed jerk" in an attempt to figure out why my '94 Xtracab 4x4 5-speed acts crazy when out on the road. it doesn't do it all the time, and i'm not sure if it's more/less likely to do it depending on having a lot of gas in the tank or not, but i wanna figure this out because it's super annoying!

hopefully it doesn't require welding the rear diff or anything because i've been riding around with a welded diff in my 240sx for years and the only reason i can tolerate it there is because that car drifts so well that it's worth it. would love to find a solution for this![/QUOT

The problem is either spark plugs, spark wires, or igniter and coil. Any one of those will cause those symptoms mine was the igniter.

cbh148

So, I take it the welded diff seemed to have identified the problem at first as being play in the spider gears, but then later on the problem ended up still being there all along because it was actually just the igniter? And by igniter, you're meaning the ignition coil? Sure hope it's the coil and not the diff, cause hotdang that's a radical difference in effort/expense required to remedy haha

tmclancey

The problem had nothing to do with the differential. That was my first thought and I eliminated that from the equation. The ignitor and ignition coil are two different things. The coil, plugs, and wires are the cheapest to change. Do those first. If the problem is still there then change the igniter. The igniter is mounted right next to the coil that little square box with a plug going into it.

cbh148

I've changed the plugs and wires already, partly for the sake of good maintenance (especially since the old plugs looked dated), but also due to some of the plug wires getting a little mangled when removing them for a compression test (which came out fine).

From what I'm seeing, the ignitor is responsible for taking the ECU's ignition timing advance signal ("IGT") and actually implementing that amount of advance, and since the amount of advance that the ECU outputs is dependent on several inputs (amount of air flow metered, engine temp, knock, and so on) then that opens the door for those inputs to the ECU being erratic and causing the timing advance amount to be erratic as well, which perhaps could be the herky-jerkiness if the ignitor was fine.

And I'm seeing that if the ignitor doesn't get that IGT timing advance signal from the ECU, it doesn't cause the engine to lose spark, but rather it just doesn't advance the timing at all, so it just sparks at the base timing setting, meaning that if the ignitor fails in a way where it goes in and out (and strangely only occurring when trying to go constant speed, in my case), then perhaps that could also cause the aforementioned herky-jerkiness.

How long have you had your problem sorted out from swapping ignitors? Hope it's been remedied for a super long time so that it's that much more valid that the ignitor was the cause of it. Wish I had another to swap on to test this on mine! I'd be thrilled if I could get this sorted, especially because it's one of the few things that really stick out like a sore thumb on this otherwise fantastic daily-driving truck.