ALH FJ40 109 relay HELP

I cannot get the 109 relay to power up in my swap. If I touch ground to the blu/yel wire it will power up. But it won't shut off until I pull the relay. I kept the load reduction relay box and the 109 relay from my donor. 2002 Jetta ALH. And the power distribution box at the battery. Can anyone tell me what wire tells the computer to ground out the blu/yel wire for the 109 relay. Thanks!

A friend of mine said to check 121/37 and sure enough I have that wire being powered by the 109 relay....

fjdiesel said:

A friend of mine said to check 121/37 and sure enough I have that wire being powered by the 109 relay....

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That should be connected to the ignition switch, not the relay. Power at this point will cause the ECU to turn the relay on. By connecting it to the 109 relay, you are making the relay hold itself on.

Yes, thank you. That is exactly what happened. I moved it to an ignition source. All is well now.

Would love to see pics of your ALHJ40

What transmission are you running, tire size and are you running stock gear ratios?


My buddy lusted over my old 4bd1t/4bd2t fj60 and fj40. After seeing the power and smooth reving power band of the vw diesel i should have never messed with those 700+ lbs swaps. Im trying to talk him into a stage 2 tune BHW in his FJ60 on an H55 transmission. He's running 33 inch tires on the stock 3:73 gears. Im thining he'd be better off with 4:10 gears but should be table fo find a 40 or 62 owner wanting better mpgs on their gasser willing to do a trade. The h55 came behind both the 2H ans 3B and guys use them for the later turbo yota diesels as well with success so i don't think the gear ratios would be that bad so long as you dont have too much tire for your gearing. The 60 being only about a half ton heavier than a 40 shouldn't be that big of a deal with a BHW if an ALH pushes a 40 with ease. You probably lost what...300 lbs ditching your F?

PickleRick, I forgot to subscribe to the thread, so I just seen your post. I am running the Coty built adapter and I am running the nv3550 from a 2004 Jeep wrangler. For tires I put on Toyo MT's 285/75r17. And I changed the r&p's to 4.56's. I did a 4BT in my 60 first. Then I went to a 4BDT2. lol. And you are right, they are nice, but HEAVY... I put the turbo from the 4bt on the 4bd and that little Isuzu could run circles around that cummins. I am thinking you are correct that the ALH is 300#'s lighter than the 2F. I have the coolers all mounted now, just finishing up the coolant lines. I will load a pic once I figure out how. Lol.

I've not yet seen an h42(1:1 final gear so crappy for a daily driver unless your top speed is 55)

You can adapt the h42 to SBC with adapter bell housing then use a tdi to sbc adapter. So....2k or more in adapters.

Or ditch the 4 speed trans for a modern over drive trans so that fj40 can cruise at 65 mph all day without sounding like the motor is going to throw a rod.

I say 65 because past 65 in an fj40, no matter how well your brakes and steering work...you need a top notch life insurance policy.

The dana 18 is plenty strong and common. It has the pass side front and rear diff drop. Has parking brake drum and can be adapted to many popular transmissions other than just a 3500 dollar h55f or nearly as costly nv4500

Another option is a ranger over drive mounted in front of the h42 to work as a 27% over drive gear splitter and sbc adapter. I found they made the h42 shift very sluggish. Too much slop for me. But it's a liveable slop in an already quirky rig.

The r150f is another option if you don't mind swapping the rear axle for a mini truck/4 runner rear axle.

My fj can 75mpg at 3200rpm... which I know is a little high... rubber OD on 35s.. at the time I hadn’t seen anything about tdi swaps only the r2.8 Cummins. I’m just about done wrapping up the AFI efi kit and the ac

I have a 88 fj62 that’s getting a ls 5.3, I have all the parts already for it but haven’t got around to it. My kids are 9 and 5 and are at the age where they take up all my extra time but I will eventually get around to it

I never felt safe over 65 mph in my 40 in hwy traffic even with all new suspension/steering/fj60 hub and 4 runner caliper upgrades. She rolls better than the dodges with the swb and high center of gravity at hwy speeds.


3200 is a little high for a tdi to cruise. That's about the top cruising rpm of the tdi marine motors.

I cruise 75 mph at 3000 rpms in my bhw passat. It's a little loud, gotta crank the radio.

The 40 has zero sound dampening so it will be much louder. This may or may not bug you. I ran a sbc in my 40 for a few years before I swapped to a diesel. I could have baked a ham in the passenger floor board with the v8 set up.

@Mxshift72 The two main reasons for the NV3550 was I bought the adapter from Coty. And they make it to fit a Jeep trans. The second is overdrive.

I changed my suspension to FJ60 springs, axles, split case t-case, power steering. I did 90-95 mph in 3rd gear when I was road dynoing it for the tune. Handles great and feels safe. But, everything is brand new...

I am still having heat issues.. My cruising egt's are 1150 F when running 55 mph. I have been talking with @PradoTDI he just changed his nozzles. So I am going to see how that works for him. I think I may need to do that and de-tune a little. When we went to the Black Hills, SD this summer in the heat and hills. It was 65 mph tops on the trip, otherwise the egt's were hitting between 1540-1650F. Too hot for me to be comfortable...

what’s your thoughts on the r2.8? You think it’s worth 8k ? +adapter plate?

I think I would have to break down abs by the h55 for the 5th gear

Well.... I think a 2.8L diesel is probably much more suitable for a 40 for sure. 40's are a brick. Combine that with 33-35in tires, lockers, etc. That all robs a lot of power. I have put about 10k miles on my build so far. Most of them this summer.

I do have a 2.0 BHW block. I have been thinking about doing a hybrid BHW/ALH. I do think that would help a ton. Better piston cooling is a big one. And I would add a Colt stage II cam. Some gasket matching head porting. And then tune it down some. Then I think it would run down the road way cooler.

@PickleRick Here is a photo of us loaded headed to the Black Hills. This is on some little 2 lane on the SD/MN border. I was reading this thread and saw that I told you I would post a pic. Sorry I forgot.

Wow nice ... is that an original fj43 tub or an aqualu aluminum?

Thanks! Its an Aqualu 10in stretch 3/4 tub, doors and tailgate. I repaired the firewall, fenders and hood. I had a guy in WI do the custom top, and its insulated. The complete underside is fj60 axles, springs, hangers, t-case, power steering, etc....

Northwest Fab Works bought out gastodieselconversions.com and with his kit, they can mate to any transmission I believe.

I found him after I bought the Coty trans adapter.
I also bought there heavier flywheel. Which was amazing on how it smoothed out the tdi and added a ton of torque.

Super cool... yea I was looking to pull the trigger on one here in a year or two and give my current 40 to my son when he turns 16 after he helps me build me the new one

Do you have a build thread on here?

Not on here. It's on ih8mud. https://forum.ih8mud.com/threads/meet-ivy-1976-fj40-w-vw-tdi.1092256/

Also, check out @PradoTDI thread on mud. He just put in smaller injectors with much success on cooling down the egt's. https://forum.ih8mud.com/threads/another-prado-in-montana.1026093/page-16#post-14083939

Give you some light reading for tonight.

I had big EGT issues before with some poorly set up 0.220 nozzles, like @fjdiesel it would run 1150 at 55mph, nearly 1300 at 60 and any acceleration would push it above 1450. The hottest I saw was 1686! New Bosio DLC1019 nozzles fitted and calibrated by Kerma have made a world of difference. I still need to do the hammer mod to bring IQ values back into spec after the new injectors, but so far I’m super happy with the results.

If you can fit an R150 transmission in your 40 there are options for changing 5th gear ratio for better highway cruising. Mine runs 2500rpm at 70mph with 4.88 gears.

You guys make me nervous on your egts. I'm using a stock bhw engine with stage 2 tune on my build with the r150. 285 tires are my target size. I have a set of 4.10 gears and a set of 4.30 gears. Im trying the 4.10s first.

I'll be ditching the heavy oem fiberglass 4runner top for a soft top but will be adding a tube winch bumper and tube rear bumper swing out tire bumper.

My lift consists of 2 inch body lift, 2 inch ball joint spacers. Relaxed torsion bars and add a leafs in some broken in ome 2.5 rear springs.

The 1st gen 4 runner is not the brick the 40 is but still not what one would conser aerodynamic.

Seems the heavy running gear puts some strain on these motors.

Stage 3, DLC1019's with the little vnt-15 and it cruises between 600-800 degrees. I have to push it real hard on hills to approach 1400. haven't really towed anything significant with it other than my dump trailer loaded with wood up a short steep hill in the yard. Kept it in 1st gear for that. I've carried weight in the bed but it didn't seem to make much difference

PickleRick said:

You guys make me nervous on your egts. I'm using a stock bhw engine with stage 2 tune on my build with the r150. 285 tires are my target size. I have a set of 4.10 gears and a set of 4.30 gears. Im trying the 4.10s first.

I'll be ditching the heavy oem fiberglass 4runner top for a soft top but will be adding a tube winch bumper and tube rear bumper swing out tire bumper.

My lift consists of 2 inch body lift, 2 inch ball joint spacers. Relaxed torsion bars and add a leafs in some broken in ome 2.5 rear springs.

The 1st gen 4 runner is not the brick the 40 is but still not what one would conser aerodynamic.

Seems the heavy running gear puts some strain on these motors.

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Doesn’t the BHW have a built in pyrometer to monitor and adjust fuel and boost to keep EGT’s in check?

Yes. Now just how much is the question, I've never done a diesel conversion where I needed to add an egt gauge. I've always put big 3.9 diesels from 4 or 5 ton trucks into cruisers so the egts were never am issue. Rpm range was. This is my first conversion using a tdi. I'm hoping it works well with the bhw as I plan to also put another of motors in the little ladies disco 2 which is a good bit heavier than the 4 runner or rover. The 3.54 ish gearing is a little better for hwy speeds.

@PradoTDI said in another thread that he can now use the full range of his skinny pedal. Which on mine, I bet I am only using the top 25% of the pedal. So I think he is on track of smaller nozzles and cut the fuel back a little.

The fj40 came with 125hp. With the TDI I am roughly at 180hp. I am sure it will still move along just fine with a little less...

What diameter exhaust are you guys using?

I am running 2.5in mandrel bends. With straight flow thru muffler. I don't have any exhaust restriction.

3” with 4.10’s and 31” tires