Quantity Adjuster calibration after replacing fuel temp sensor

[Tempestkic]

Hi guys,
I just replaced my fuel temp sensor on my 2002 alh injection pump. I watched one or two videos on YouTube and then went for it as it seemed pretty easy, but it is my first time working with an IP and didn't realize how finicky they can be.

There was quite a bit of crud built up on the quantity adjuster when I opened it up so I took some brake clean and a toothbrush and gently scrubbed the electronics in there. I had the bright idea to try and remove the top part of the QA electronics to make cleaning easier and they appeared to be held in place by a couple small screws. I removed the screws and realized that it was not so simple to disassemble. Rather than dig further into it I put the screws back in but i noticed that the copper (‽) thing on the left side of the sensor had shifted when I had loosened the screws. I referenced a photo I saw online which had this copper thing moved as far towards the front of the car as possible, so I matched that. I reinstalled the top case of the QA without realizing there was an additional adjustment with this piece. Anyways I now have a p1562 (upper limit quantity adjuster) code. It idles a bit rough at idle now and when coasting, fine under throttle. Ran great before I messed with it despite the fuel temp sensor code.

I have read a number of threads on here but haven't been able to find anything on how to clear this code by adjusting either the copper thing inside or the top of the case using the hammer method. Any advice would be appreciated. Thanks.

I don't currently have access to a vcdm, but do have a cheap obd2 reader.

 

[TurboABA]

I think you need to realize 2 things:
1 - a reader will READ codes.... so no bueno if you want to do more than read codes
2 - clearing a code only "solves" a problem if it's a flaky, intermittent issue.... when you have an actual problem\failed component, you need to fix\address it before you clear a code... otherwise, you're not really doing anything.

 

[jmodge]

It's probably running rich. Best thing to do is invest in VCDS. If you don't want to do that, study "hammer mod" and try decreasing the fueling.

 

[Mongler98]

Nothing you do will fix your screwups. And you have many.
Why was there crud on the inside of your IP? It should be flawlessly clean.
Take the ip off and send it to a qualified shop to be rebuilt or have your car towed to a tdi guru mechanic from our list. You are over your head on this one and anything you may have done or will do from here on out on the ip may cost you more than it's worth.
The fact that its dirty inside is a sign that it needs to be serviced.
If you bent that plunger you are screwed.
Do not attempt hammer mod.
You did not move the QA but you moved the plunger. If you try and move it now you might make it travel too far and snap it off or bend it more or even at all.
You have really 2 options. Have a pro fix it or try and gamble 2 grand yourself.

 

[jmodge]

Also scribe a reference mark on across the QA and pump body so you can always go back to where you started. Another thing to look up is "ALH Diesel Purge". Sounds like it could use a good cleaning.

 

[Mongler98]

If you insist on trying yourself. Do this
Take the cover off. Scribe the line on the body and the QA to referance where you are.
Remove the QA and replace the seals and install it but move it all the way to one side and scribe a line from the old one and then again on the other side like a hammer mod.
You must have vcds and a proper cable.
Put the QA back were you started and measure the difference from the 2 side markings and if your in the middle then put the plunger cam in the middle if you are 1/4 then put the cam respectively 1/4 from center and so on.
Tighten her up and run vcds and perform a hammer mod. Do not move the QA without vcds for IQ.
This is still really risky though and somone with your skill level is gambling with a few grand.

 

[TurboABA]

The YouTube vids must've not mentioned that this will cost you $1k to replace the pump as a result of this Mickey Mousing around.....

 

[Tempestkic]

Wow some real doom and gloom on here.
I've rebuilt engines, transmissions, just never been inside an IP. I opened up the QA again last night and had a closer look at where the copper adjustment thingy on the left side of the QA sensor was. I readjusted to a more central position and could feel it kind of click back into the place it's been sitting for the last 20 years. I also checked to ensure the arm does its test when the key is turned to the on position. After all this it's running great again and no p1562 code.

I understand I got lucky here. Is it not normal for some diesel residue to build up after 20 years and 320,000km?

 

[TurboABA]

Wow some real doom and gloom on here.
I've rebuilt engines, transmissions, just never been inside an IP.

Please excuse my ignorance, but when you start off by posting background education as:

Hi guys,
I just replaced my fuel temp sensor on my 2002 alh injection pump. I watched one or two videos on YouTube.....

followed up by such technical terms as:

the copper adjustment thingy on the left side of the QA sensor

its hard for me to determine deduct your competence with any degree of accuracy...... maybe others are better at this than me!

It's good to hear that you were able to Crtl+Z your issue.

 

[Mongler98]

Yea.. context and history is everything.
100% of all the threads that started with "I opened my ip and moved things" ends up in a rebuild.

There should be no anything but shiny clean metal and what not.
Change your filter every 10k and use quality stuff. Maybe your african diesel is just that dirty? No idea

Glad you fixed it but you seriously need to vcds it and check the QA number. I still stand by not performing a hammer mod without vcds as it's still been moved around.

You useing words like copper thing and I watch videos on YouTube to do the work does not instill us with confidence that you are capable of this job.

 

[Tempestkic]

Yes, I was just trying to keep the post short as it was already lengthy. But reading comments such as

Nothing you do will fix your screwups. And you have many.

Are not supportive and is going to turn someone off of trying to fix problems themselves in addition to turning a noobie like me off of participating in this community. Am I just being sensitive here lol?

 

[TurboABA]

Newsflash!
You're a snowflake!
Cry yourself to sleep tonight and then come back when you're ready to play with the rest of us!

 

[Mongler98]

Yes, I was just trying to keep the post short as it was already lengthy. But reading comments such as

Are not supportive and is going to turn someone off of trying to fix problems themselves in addition to turning a noobie like me off of participating in this community. Am I just being sensitive here lol?

NA. don't worry. its just me being me... its the internet, some of us can be ruthless sometimes. You have to understand the picture that we get from a post like yours. Don't worry, many others have had worse reactions also TurboABA has been on the pill or something latly... gezze bro... lighten up a bit.....

 

[Franko6]

Ruthless, yeah, I guess so. I remember the first time I 'screwed up a pump'. The shim between the main shaft and the distributor shaft fell out. My buddy says, "Well, it's already broke. I doubt it's going to get any more broke."

So, we dove in, and between the two of us, not only we fixed it, we figured out how to make it better.

As a footnote, the fuel temp gauge is easy enough to R & R, but what usually seems to happen is a wire breaks or loses contact. Rarely have I found a bad fuel temp switch.

Residue on the IQ (actually, everywhere in the pump...) is usually caused by 'alternative fuel'... biodiesel. Now, I know all the claims that certified bio will not do that. Only 'waste veggie oil' does that. The truth of the matter is glycerin does that. It's the element in biodiesel that 'should' be eliminated under process. There are those who exclusively went to their 'BioStation' and had the deep fried look on their internals. That is what you were scrubbing off your IQ. There is little reason to try to go further than a cleaning. The IQ is not readily disassembled.

The VCDS is worth the investment if you expect to keep the car. Otherwise, you hopefully can find someone willing to share their equipment.

 

[Tempestkic]

Thanks for the advice Frank. Genuinely surprised that they morning after posting in here there was already 4 or 5 responses

 

[burn_your_money]

For the purpose of future searches, the temp sensor is on the top of the QA and does not require the QA to be removed to replace the sensor. That would have saved a whole lot of worms from getting out of the can. All that needs to be removed is the top cover.

@Tempestkic VCDS would be a worthwhile investment. You will need it for the timing belt. If the car is running properly, there is no need to stress over urgently getting the QA set exactly correct. If you took a poll of what everone's QA is set at, you would find a wide range. Outside of that range you will either have codes or driveability issues. Since you have neither, you'll be fine but probably not optimal.

Did you happen to take any pictures of the crud you speak of? A grimy coating is common and usually not serious. A good fuel cleaner will take care of this. People doing a Diesel Purge often see junk coming out of their pump. Rust or corrosion can be serious or it may have no effect. The main thing is to ensure that the fuel filter gets changed and you use good, clean diesel going forward. If you keep water out of the fuel system, the rust can't progress. Water also enters by air leaks in the fuel system which is harder to avoid.

 

[Tempestkic]

I do have a picture but don't see an easy way to attach photos, what am I missing?

I have already replaced the fuel filter, the crud was dark, kind of like varnish. Not rust or corrosion. Do you think a purge is necessary if everything is running fine?

 

[TurboABA]

I do have a picture but don't see an easy way to attach photos, what am I missing?

How to upload photos in Xenforo and use them in your posts

This is a temporary place holder for a proper FAQ on how to upload photos to the new system: To upload images to the image server: Go to the "Media" section. The link is found in the top bar. click on "Add Media" found near the top right corner. You will get a popup on where you want to...

forums.tdiclub.com

 

[Tempestkic]

This is the QA after cleaning, you can still see some of the brown residue on it. That copper adjuster thingy (have yet to see anyone describe it with its real name) on the left side near the temp sensor is in the position which caused me all the problems in this photo. I moved it about 1/8" clockwise to fix my issues.

 

[Mongler98]

I would run a bottle of diesel purge though it and replace the filter with a higher 2 or even a 1 micron filter.
Run the diesel purge via the can and the hose to the IP. Do not add to the tank. Just run it solo. Let it sit with that in the IP for at least overnight if possible.
I've seen bio varnish. Ive seen dirty mud fuel coating. That sir looks like somone ran it with engine oil for years.

 

[Tempestkic]

Hmm. I purchased it about a month ago for a reasonable deal and have been playing catchup on all the maintenance since then. Thanks for the advice.

 

[Franko6]

I would be more worried how the rest of the pump looked, like the distributor shaft and the cam plate. That may be a skill set above how deep you want to dig.

My opinion, if it's running.. Call it good.

Something we started doing years ago is to block the injection pump off, so it won't drain back to the tank, fill the pump with purge and leave it there as long as you can. In our case, we might be doing some major service, so the longer the pump sat around, the longer the purge would 'percolate'. Before attempting to start the engine, leave the injector lines off , remove the injector lines from the pump and remove the glow plugs, so the engine spins faster. Use the starter to squirt the purge out of the pump onto the ground before you prime your injector lines. You don't want any of the crud going into your injectors. Leaving the gp's out also makes priming injector lines go quicker, as the starter spins faster.

Setting IQ quantity can be done without the VCDS, although, it takes more time and guesswork. If the IQ body is loosened enough that the box can be tapped back and forth, there is a 'way too much' point with the lid moved toward the driver's side. 'Way too little', is the opposite side, where the engine won't even run. Starting with the pump running rich, mark the lid where you can judge the movement and incrementally move the lid toward the passenger side. Between movements, drive the car. In 3rd gear, 35mph, go to WOT(wide open throttle). When the speed hits 40, count three seconds and note mph. Keep incrementally moving the IQ lid toward the passenger direction and checking engine speed. When the speed drops after a three second count, you went too far. Move the lid back to it's previous spot where speed was not lost.

 

[Nevada_TDI]

Frank, you are always a great fountain of knowledge, and I always learn something by your posts.
For the record, if Frank says something take that information to the bank.
The other thing is, Frank 's shop is really busy every single day, and the fact that he takes time out of his day to post on here is nothing short of fantastic.
FYI, sometimes Frank may come off a bit sharp, and he is not attacking the person he is trying to help out of a jam, he is hoping that his posts help people fix their own problems.
I have been talking/working with Frank for 12 plus years, and if he gives advice to do or not do something, take it to the Bank.

 

[burn_your_money]

Lots of pumps came into the shop like that. I wouldn’t worry about it in regards to the health of the pump but I would do a diesel purge to clean it since it’s not helping anything.
I don’t think it’s oil, but old fuel. Maybe the car was driven infrequently and would go months without refueling, or perhaps a whole winter for snow birds.

 

[Mongler98]

Lots of pumps came into the shop like that. I wouldn’t worry about it in regards to the health of the pump but I would do a diesel purge to clean it since it’s not helping anything.
I don’t think it’s oil, but old fuel. Maybe the car was driven infrequently and would go months without refueling, or perhaps a whole winter for snow birds.

Old fuel? You ever see that issue? I just used the last of my diesel and it was 5 years old. No issues looks new..... that was stored in a container that was full.... I constantly use diesel that is at least 1 year old at times never seen an issue.

 

[burn_your_money]

Old fuel? You ever see that issue? I just used the last of my diesel and it was 5 years old. No issues looks new..... that was stored in a container that was full.... I constantly use diesel that is at least 1 year old at times never seen an issue.

I’m thinking half full sitting in a car for extended periods. Not properly stored at all. Probably with condensation in the tank from short drives. I saw similar in a lot of old tractor pumps.
I’ve taken apart waste motor oil pumps and they don’t look like that. It doesn’t look like waste veggie oil to me.
Perhaps poor quality biodiesel but I don’t have known experience with that.

 

[Franko6]

Nevada, I appreciate your support, but you make me out to be better than I am.

Yes, I agree, it's not a normal-looking pump. One of the problems with bio-diesel/ WVO is that is will carry water through the system and it looks almost rusty. Some put waste engine oil in the tank! UGH! The ones that look like they are 'deep fried', with congealed glycerin and fat are the indication your engine is getting toasted with improperly processed veggie oil.

If it were mine, the pump would get torn down to it's components and rebuilt, assuming it's worth rebuilding.

Overall, and the funny thing is, seldom does the fuel temp sensor go bad, and that is the original reason for the OP to look. An inoperative temp sensor may keep the advance module from retarding when fuel temps are read correctly. Or it could go the other way...

My own 02 ALH had fuel temp reading of 0C, which was fixed eventually, by replacing the wiring loom to the ECU. 20 years old, and it doesn't want to work anymore? ****ty wiring... LOL.

 

[Houpty GT]

For future reference on cleaning and adjustment:
Quantity Adjustor Cleaned! | TDIClub Forums