Jeep TDI conversion-newbie with questions?

Jeep TDI conversion-build thread

Hi everyone, this is my first post. I am a newbie, as this is my first diesel. I own a 97 Jeep Wrangler and want to do something cool. I have had v8s in my s10 and 4 liter jeeps but everyone has one. So after a ton of reading I have decided to go with a 1.9 TDI. I just started collecting parts last month. I am picking up a car on wednesday it has a 98 1.9 AHU engine with only 67k mioles.


Any input is great except if you want to tell me to do a 350 or something else. Parts are already purchased.

I would start by reading some of the other TDI to non-VW conversions if you haven't done so. A lot of your questions will be answered as well as a whole bunch you haven't even thought of yet.

1. Using the stock fuel tank if fine, but you cannot use the efi fuel pump. The most fuel pressure you can have running into the injection pump is 2-3 psi, otherwise bad things will happen. When i put a TDI in my truck, i just took the fuel pump right out and it has been fine. It was a bit of a pain to prime the first time but not a huge deal.

2. I have never had anything to do with an MTDI setup but i would recommend keeping the electronics. In all honesty it took me 20 hours to comb through the harness and figure out what i needed to do and 2 hours to get a running truck. There are only 3 wires that need to be spliced into the Jeep harness to get a running truck. I think it is well worth the effort to keep the OBDII and the chippability.

3. I kept a stock Toyota radiator and made my own piping to make it fit. The VW stuff isn't going to work great because you are going from a transverse setup to a longitudinal setup, so most of the hoses won't fit anyways.

4. It seems like the thickness of your wallet is the limiting factor here. I am hoping a chip, injector and a different wastegate turbo will get me around 150hp and 250 ft/lbs. I think i will be happy with that as it is more than double the torque of the 22re that i used to have.

5. I would definitely change the timing belt as well as the idler and tensioner. It will take you less than an hour if the engine is sitting on the bench. Given the age of the engine and length of time it has been sitting you might think of change some of the other seals on the engine like the cam, crank and intermediate shaft seals. On the other hand, if its not broken don't fix it.

If there is anything else you can think of feel free to ask away. I am just in the process of buttoning my truck up and starting to crank up the power, so far it is pretty awesome.

Luke

Thanks for all the input. What are the advantages of keeping the electronics and the OBDII? Besides the ability to chip. I do like simple. exspecially for offroading.

Also if any one see's anything they want off this car as far as parts, let me know. Anything I dont need to use is for sale.

Keeping the electronics will allow you to use vagcom to do all kinds of things. The most useful is checking for engine codes, but you can check the injection timing, the injection amounts, use it for mods like the hammer mod, the list goes on. There are also scan gauges that you can plug into the OBDII that can show engine RPM, boost, fuel consumption, coolant temp, voltage, engine load, etc. This is very nice if you don't want to have a million gauges and not modify your gauge cluster. The ones i saw were only about $70, which is a lot cheaper than a set of decent quality gauges. Also if you choose to run an MTDI pump you will need to get a pump built. I have heard someone by the name of tintin, will build it for around $500+ if the parts are supplied. The way i look at it, that is the cost of a chip and bigger injectors, which will net way more power.

Agreed. I aready use a obdII reader that I bought. It uses bluetooth and operates on my droid. It also does mpgs, 0-60 and 1/4 mile times. There is a guy that is building sweet mechanical pumps for under $300. just fyi. So you need the ECU to the new engine on glow plugs, pump, map, and ?. What were the 3 things you spoke of that needed to be spliced to run. Here is a Dumb question. Run both ecu's or can I eliminate the jeep one. Is it needed to run other things. Also is the 98 jetta gonna have the drive by wire skinny pedal and is it required.

Oh ya my obd reader also does hp and torque.

What is the Jeep ecu needed for?

If you look here:

http://www.haywood-sullivan.com/vanagon/TDI/tdi-technik-eng.pdf

You will see what sensors you HAVE to use to run the engine without codes. The EGR can be deleted with a chip or other ways and the clutch/ brake switches will cause codes if not used but do not really effect anything unless you are planning on using cruise control.

If you look here:

http://www.haywood-sullivan.com/vanagon/TDI/tdi-technik-eng.pdf

You will see the wiring diagram for the engine in that car. I can't remember exactly what i did, but if you look at the power supply relay (J317) you can probably make sense of it. In my truck i used the EFI relay, a fuel pump relay would also work to replace the VW power supply relay. If i recall correctly, you need to have + going to the relay and the VW ecu will ground it out after a system check, this will then supply power to the rest of the engine and sensors. There were 2 wires going to the power supply relay and a ground.

Once you get the car i would strongly recommend labeling EVERYTHING, even if you think you will remember and it is obvious. This will save time and frustration later, also make the labels out of something that can still be read with a dirty finger print on it. Blue masking tape and silver sharpie is not a good choice, ask me how i know. Take the engine harness and cut the sheathing off. There is some stuff that can be deleted right away, such as the EGR wiring, coolant glow plug wiring, the A/C wiring, the starter wiring and the vehicle speed sensor (again if you are not using cruise control). Next study the wiring until you know exactly what everything does and what the wire colors are. Now get a Jeep wiring diagram and see where the two need to meet. Assuming you want the gauge warning lights to work, there will be some splicing there (oil pressure, battery, engine light, coolant gauge) as well. I left as much of the Toyota wiring alone as i could until i was sure i wasn't going to need it.

I know how overwhelming the wiring can be as my truck was my first engine swap, but it isn't impossible and there are lots of knowledgeable people here to help you out once you have specific questions. Right now start reading everything you can about TDI's because there is lots to learn.


Luke

anks for the info again I remember now looking at those about a month ago. Just been saving all my diesel info to a drive at work. Havn't had time to sift threw it all. But now I know thats in there.

thanks Again

Nothing to add, owning a 1998 Jeep with the 2.5L I'll be following this. Keep us updated!

give'er! I'm doing the same with my 2000 tj and an alh motor with 100,000 km. make sure you clean the carbon out of the intake and throttle body and check your timing belt before you put er in.

im currently waiting on you know who to come out with they're kit for the ax15's... since they decided to do the yj's first

my plan is to go with injectors and re program for injectors, immobilizer delete and egr delete. + intercooler +snorkel + streight stack exhaust.
obviously doing an electric fan convert as well.

stage two would have to be a bigger turbo and shot peened connecting rods + custom pump ( might have to backtrack and jiuce up the injectors again when i get to this point. i want to find out if my first mods will be enough to satisfy the power cravings given the jeeps purpose. alh being lighter and more toruqey than the 4 banger much is to be discovered)


Can I please get some more info on the fuel pump situation ill be in the same boat. to get in there and take out the pump is a sob. might as well replace the tank for higher clearance/cleanlyness +durability

what problems can happen leaving a stock jeep pump in the tank ressurizing the lines? what pressure would a tj's pump operate at?
best alternative / suggestions ?

The VW injection pumps can't take very much pressure, i have heard 3 psi is good. Assuming the jeep was efi, the pump is probably way too much pressure. Some people have used a inline fuel pump designed for a carburetor. If you search for "lift pump" there is all kinds of info to read up on.

Ya I have seen people use the blue holley pump mounted on a frame rail. When I did a previous swap of a small block with a carb and left the FI pump in the tank but not wired in. I had no problems.

The engine is out of the donor car and on the stand. Time to start cleaning. Also still waiting on the trans to be shipped to me. Then I can start putting it together on the floor.

a-dem said:

im currently waiting on you know who to come out with they're kit for the ax15's... since they decided to do the yj's first

Click to expand...

Why wait for HP. It could be a long time. Just do this build http://pirate4x4.com/forum/showthread.php?t=881539&highlight=and get a r151f bell housing and bolt it all up to the acme yota kit you can get now. And you have the option of running your stock np231

The G and W series bell housing does not mate up to the R tranny. The Acme kit is designed for the G and W series bell housing and trans.

Its the turbo trans bell housing. 4 banger on engine side. r on the other.

What I have is a custom tranny combination for Toyotas. It's a Toyota input shaft put into a Jeep AX15 (same as R150 and R151f). I have the 3.0L V6 bellhousing so it will bolt right up to a Toyota and uses the Toyota clutch disc. If you get a 22RTE turbo bellhousing you could bolt it to a 20R, 22R, or 22RE or the acme kit.

So you are saying that using the bellhousing for the turbo trans you can make the 150r/ax-15 and bolt it directly to the acme adapter?

If it will bolt up to the 22 it will fit the acme kit yes. So now I can build a higher hp and torque tdi and not have to worry about the tranny.

Or you can do the same with the ax5 and swap in a toy g or w(dont remember which) input shaft and bell and use your stock np231.

Good to know. Thanks

Ahu?

Please pardon me if I missed something here, but the motor that is pictured in the second post doesn't look like any AHU I've seen. It has a cable-operated injector pump. The AHU, unless it has been converted to mtdi, is electronically controlled. I certainly don't claim to be an expert on VW diesel engine identification but that looks like a AAZ to me.
Brent

The injection pump does look very AAZ, but then i can see the needle lift sensor on the 3rd injector?!?

I am glad that some one noticed. The car was a gas that the guy swapped over to a AHU but this is my first diesel and I wouldnt know what I was looking at if it hit me in the nuts.

If I post some better pics of the motor and you guys could tell me what I have it would be great. It seems like all the sensors are still place but your right it is a cable operated throttle and I was told it ran but I cant find an ecu anywhere, but there is the big round engine plug there and it goes into the factory gas engine harness, but have yet to pull it all apart. Also the cover on the timing belt is maked AHU and I have the reciept from the motor when he bought it with the make ans vin number from the donor car.

Pics to come 2 hours.

here is a few pics. Any opinions would be great.

Sorry about the giant pics

Looks like a AHU that PO put a manual IP on.

Was the wiring on the top of the 3rd injector connected to anything when you got it>?

I would say only8V is right, it looks like you just need a TDI injection pump. If you need to buy one, you might consider getting a bigger pump from a later year TDI. It seems like all of the TDI wiring is there, stuff just isn't connected.

The ECU was wedged up near the heater core on the Passat i stripped, i am guessing it is in a similar place on the Jetta.