Drivability issue: 2H installation behind 4 speed "bucks" under light throttle

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rchalmers3

I speak Toyota
Joined
Jun 29, 2007
Threads
45
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1,539
Location
Playas de Nosara, Nicoya Peninsula, Costa Rica
I recently completed a 2H diesel swap into my 1983 FJ60. My '83 is going to be my DD and has the stock 4 speed. Specific drive train mods to the '83 include 33's, a 3" spring lift, 4:88 gears, and front and rear ARB lockers. For the "donor" I used a 24v 1986 Canadian 2H ( Called a "G Unit") that was coupled to an automatic. Spector Off Road was sourced for the flywheel, bell housing, clutch and other small parts necessary to mate the 2H to my 4 speed.
The conversion went very well. I am proud of my accomplishment and intend to enjoy the product of my labor (and expense). However.....
After driving the truck, there is a rather severe drivability. When I am neither accellerating or coasting, but right where I am using light throttle to maintain speed, the truck starts what I call lashing, or bucking, where the motor lugs, then accelerates. This causes the driver to tip in and out of the throttle. The truck starts an abrupt accelleration/ deacceleration mode that intensifies! It's Gnar gnar!!!
Before making the conversion I had driven both vehicles at least 1500 miles. Neither truck exihibted this problem. The auto trans on the "donor" Cannuck truck was sick, but did not lash or buck as described. The clutch is new and only occurs when the disc is clamped to the flywheel (engaged).
I have experienced this with larger diesel trucks I have owned and driven (Unimog 416's). Adding weight seemed to diminish the effect. I am speculating the fuel delivery is too lean, but before getting into that I thought it prudent to make an appeal to the brain trust... :D
Thanks to all in advance,
Rick
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Nice job,looks like a store bought one:D

As to your problem,12HT owners manual owners often have a similar problem with the engine bucking over rough ground and the cure seems to be to add some more springs at various angles to the throttle arm.
That wouldn't solve the root problem but it may help you while you work on the other .

Certainly sounds like a fuel supply problem,maybe gummed up injectors.

I might try some injector cleaner for starters,it also cleans surfaces inside fuel pumps.
You could also check for leaks in the vacuum hoses to the pump.
Fuel leaks in pump and governor could also have an effect,even minor ones.

Fuel pump settings do not change over time(not much anyway) so at this point I wouldnt go fiddling with fuel settings if it was running ok before.
 
RoscoFJ73,

Thanks, I'll certainly add some injector cleaner to the tank for a systemic cleaning. Do you think it's necessary to remove the injectors and have them cleaned and tested?
As for the additional springs on the foot feed, I spoke with my wife about this. She's agreeable to have it be a little stiffer down there. I'll let you know how that turns out.... :ban:
 
The Automatic and Manual transmission Injection pumps are different.

Also make sure the vacuum diaphram is lubricated and does not have
any holes in it.

There are hoses that run from the butterfly on the intake to the diaphram
unit that control it, make sure the venturi nozzles and hoses are clear.
 
From my experiences, when my fuel sending relay was pooched, it caused my edic motor to turn on, then off, then on etc., making my BJ60 to lunge through an intersection, jerking back and forth, a little nursing of the clutch and I made it to the other side.

Now, I'm not too familiar with the 2H motor, but perhaps this can provide you with some insight from a different angle.
 
RoscoFJ73,

Thanks, I'll certainly add some injector cleaner to the tank for a systemic cleaning. Do you think it's necessary to remove the injectors and have them cleaned and tested?
As for the additional springs on the foot feed, I spoke with my wife about this. She's agreeable to have it be a little stiffer down there. I'll let you know how that turns out.... :ban:

If the injectors haven't been done in god knows when ,I would say yes.
I think Owensexport's advice on the vac diaphragm is a likely cause also.
Start off cheap.
I would try and keep a spare set of rebuilt injectors on hand.
The dont clean them like the old fashioned types,they replace the nozzles with a kit, and then bench test the opening pressure.

Got to keep wifey happy ;)
 
How did you deal with the injection pump hook-up, given that it came from an automatic? Are you using the vsv to open and close the intake butterfly?

As far as the difference between the automatic equipped engine injection pumps and the ones for manual transmissions, there are not huge differences, from what I can discern:

-auto trans set up pump dumps more fuel in at start up, but the other rack settings on the pump are pretty close to the manual tranny version
-the auto trans model uses the vsv, while the manual model uses EDIC.
-there are some differences in how the throttle cable attaches and in the brackets to mount the throttle cable to the intake manifold.

I also have a 2H that originally had an auto trans, and I am planning to keep the same injector pump and rig up the vsv to operate from the key switch. It doesn't look problematic to use the automatic specific injector pump with a manual transmission, but maybe I'm missing something...
 
I might add another thing to think about on it instead of extra springs on the throttle. I would call up my local Radio control car dealer and get some hydraulic dampers from the suspension of an rc buggy and mount one of those up on the linkage. This would keep the throttle from being heavy but will slow the action of it. Think bouncing of the front end of a truck when there are no shocks installed or they are shot....same concept. Just food for thought.
 
Hi Rchalmers3,
l just swapped in a 2H from an auto into a HJ60 with a bad engine,it did the same thing like you said,more on 1st and 2nd gear than 3rd and 4th.all l did to fix the problem was to tighten the throttle cable,make sure there is no slack.
And Henry james,go for the swap,leave everything on the auto engine,the VSV shutoff has a round plug,the plug is already on the 5 speed truck,all l did was plug it in and the VSV works.
Simon Liew
TLC import connection
Winnipeg
Canada.
92 HDJ81
92 HZJ77,soon to be lifted,snorkeled,locked
89 BJ74
84 BJ60 SO trail truck
82 BJ42 project rock
83 BJ42 needs body
 
Hi,
by the way,l have a 2H bellhousing,flywheel,clutch and release bearing with fork for sale
Simon
 
From my experiences, when my fuel sending relay was pooched, it caused my edic motor to turn on, then off, then on etc., making my BJ60 to lunge through an intersection, jerking back and forth, a little nursing of the clutch and I made it to the other side..

Good Shot Nick .. this can be caused by the oil sender and a dying alternator .. but you can test it disconecting the EDIC plug and see if the problem continue ..
 
Good Shot Nick .. this can be caused by the oil sender and a dying alternator .. but you can test it disconecting the EDIC plug and see if the problem continue ..

...and in this case, given that the engine originally had an auto trans behind it, and thus the injector pump unique to that is what is in place, there won't be an EDIC system at all to worry about.
 
Wow, you guys are sharp! Thanks everybody for your attention. Henry James #47: word. When I made the swap, I converted the truck to 24v and kept all the vacuum thingies for the shut off. (where I live all the trucks have a factory pull cable to operate the shut off lever on the pump. I'll add that cable as a future install if the vacuum stuff ever goes bad) Thus conversations and recommendations about EDIC don't apply... To those of you who made comments along those lines, my aplgoies for not specifying the details of my conversion. I can see my initial description was incomplete.
As for The vacuum system, I did notice there is some leakage. Brakes work satisfactory and vehicle shut off system functions, but it won't shut off imediately after starting, like the vacuum needs to build up or something. Again, I don't have but a few weeks with this truck, and don't know what is and is not acceptable...
Simonliew, I had the throttle cable off to route it through the firewall for the conversion. Your experience and symptoms sound exactly like my experience, so your suggestion to remove slack from the cable will be my FIRST action, when I get the truck in my hands. I performed the conversion in SoCal, where I'm from. I then put the truck on a boat for Costa Rica, where I live. I should see it in another month.
I photo documented the conversion. While I'm happy (even proud) of the way it turned out, I don't want to re-hash what many of you have done or are doing.
Thanks again to all.
Rick
 
...and in this case, given that the engine originally had an auto trans behind it, and thus the injector pump unique to that is what is in place, there won't be an EDIC system at all to worry about.

I'm not clear in your question ( could be my english ) but all 60 that I've seen with the 2H auto or manual have a EDIC motor ..
 
Well, I can't speak for all years and configurations that the 2H engine was used, from 1980~90, but in the case of my 2H it's a 1986 and there is no EDIC.

The engine manual I have, Toyota 2H, 12H-T Engine Repair Manual, Nov. 1985, shows, pg. FU-29, shows a drawing of the two injection pumps for the 2H and 12H-T. There is a third pump shown on the page too, "Injection Pump (A/T)". The A/T version of the pump and the 12H-T version share a similar-looking governor on the back of the pump. This is because both use pneumatic actuated governors. The mechanically-actuated governor looks different. The same page, FU-29, shows the rod that goes from the EDIC motor as "EDIC Motor Connecting Rod (M/T w/EDIC System)", so the EDIC seems specific, at that point in time, to manual trans applications of the 2H.

Perhaps earlier versions used the EDIC for A/T applications, and perhaps different countries got different set-ups for one reason or another - this may explain in part why you haven't seen the vacuum-actuated governor on 2H + auto trans set ups, Tapage.

A later page, FU-32, shows a series of adjusting levers for the governor, and there are options between "w/o EDIC, w/EDIC, w/o HAC, w/HAC, in their various combinations ("HAC="high altitude compensator").

Page FU-33 shows the same governor used for "(2H A/T and 12H-T)"applications. For this type of governor, there are two adjusting levers pictured, one for A/T and one for M/T. So, the 12H-T-equipped trucks may have utilized the same vac.-actuated governor in both manual and auto trans applications - I can't say for sure though, as I haven't seen too more than a couple of 12H-T's so far, and have just the manual to go by.

I wish my scanner wasn't kaput or I'D post up pictures of those pages mentioned above.

No EDIC for my truck anyway. It's a fine system and all, but I like the idea of having fewer wires involved, no fuel control relay, no EDIC motor and no connecting rod.
 
Hi Rchalmers3,
l just swapped in a 2H from an auto into a HJ60 with a bad engine,it did the same thing like you said,more on 1st and 2nd gear than 3rd and 4th.all l did to fix the problem was to tighten the throttle cable,make sure there is no slack.
And Henry james,go for the swap,leave everything on the auto engine,the VSV shutoff has a round plug,the plug is already on the 5 speed truck,all l did was plug it in and the VSV works.
Simon Liew
TLC import connection
Winnipeg
Canada.
92 HDJ81
92 HZJ77,soon to be lifted,snorkeled,locked
89 BJ74
84 BJ60 SO trail truck
82 BJ42 project rock
83 BJ42 needs body
Is it possible to get more info on the VSV work around. I've converted an auto to a 5sp MT and bought a used EDIC but my 2H fuel pump doesn't look to be a simple add on. Any help or pictures would be appreciated.
 
RoscoFJ73,

Thanks, I'll certainly add some injector cleaner to the tank for a systemic cleaning. Do you think it's necessary to remove the injectors and have them cleaned and tested?
As for the additional springs on the foot feed, I spoke with my wife about this. She's agreeable to have it be a little stiffer down there. I'll let you know how that turns out.... :ban:
he's talking about the mechanism that attaches to the fuel injector pump. from factory they come with two springs. Mine had only one left, replaced with new ones, no more extreme acceleration/surging/deceleration/etc.

this thread explains the problem, and there are links for places you can order the springs from.
 

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