Motor Running Without Pump Plug?

After replacing the glow plugs (which were stuck, requiring the cylinder head to be removed, etc.), the timing belt was replaced and completely adjusted. After that, the car didn't always start; sometimes it would, sometimes it wouldn't (VP 37 with a 2.5-liter 5-cylinder engine).
After disconnecting the 3-pin connector from the pump and manually connecting the shut-off valve to the ignition power, the car started as usual.
According to the instructions, the other two cables are supposed to be for "valve pre-setting." Meanwhile, an error has been written to the memory.
Could it be that after troubleshooting, the car will run normally again? Or is it possible that I need to test all the cables at the connector first?
It's a VOLVO 850 TDI with the Audi 5-cylinder engine.

hello Stefan,
The other two cables go to the solenoid valve for the electronic injection start control. The basic setting of the fuel injection pump is crucial if you want the engine to start well both when it's cold and when it's warm.
I first tried it on an AAT (Audi) engine. I adjusted the pump precisely using VAGCOM. It practically wouldn't start when warm. If you slightly adjusted the position of the pump, everything was suddenly fine.
The adjustment of the solenoid valve can also be precisely controlled using a diagnostic device.
will be checked.
Best, Jan.

"VAG-COM doesn't work with VOLVOs because it seems they use a proprietary protocol. But... how can I take the car to a VOLVO dealer and have them connect the diagnostic tool if the car only runs with the connector unplugged and the starter motor bypassed?"

Stefan, why don't you try it my way: Loosen the pump slightly and then carefully adjust it a few millimeters. Try it one way, then another. Maybe mark it beforehand.
In the T4 forum, you constantly see posts stating that after a timing belt replacement...
The starting problem occurs.
Best, Jan.

...I don't know if they knew...
"However, I can't adjust the pump directly. The belt is secured by two tensioning pulleys. The front pulley has a marking to ensure the belt has the correct tension, and the rear pulley has a marking for adjustment (forward/backward). By adjusting the rear pulley, you can then use the front pulley to properly tension the belt again."
If I were to actually test your system, I would probably need the entire day tomorrow.
In the past, with the 1.6-liter diesel Golfs, you could at least adjust the fuel pump with the help of another person while the engine was starting.

To adjust it, the rear camshaft gear of the pump drive needs to be rotated relative to the camshaft. To loosen the central screw, you need an extension and a holding device for the camshaft gear. I made something like this myself from a piece of flat iron (30x6 mm) and two M10 screws, with a lever arm of 70 cm. However, it's a bit weak! 30x10 mm would be better.
Christian.

Hello Christians,

The idea is good. However, the impeller is positioned with the marking exactly in the center.
Where should I position the indicator mark on the pump impeller? Should it be more towards the bottom or more towards the top?

hello again - I was a bit confused - I have the same engine in my bus! With this (ACV) model, the pump is fixed, which is correct. The injection timing is correctly adjusted when the pump is pre-installed in its basic setting (0.55mm static preset with the measuring gauge) using the VAG diagnostic device, by rotating a deflector pulley. This pulley is eccentrically mounted and, when turned clockwise, advances the pump timing, while turning it counterclockwise delays the timing.
The corresponding tensioning roller compensates for changes in belt tension using its spring force.
Under no circumstances should you loosen the mounting screw at the rear of the camshaft!
It's completely different in the Audi; here, you can still adjust the pump! There are only two fixed idler pulleys.
Best regards,
Jan
P.S. To adjust the timing on your engine, you only need a standard 6mm Allen wrench.
The swivel bearing also has a basic setting . A pointer attached to it aligns with the flange contour of the cylinder head.
You can remember the position of the role by using that as a reference.
The mounting bolt for the idler roller should be tightened to 20 Nm.
If necessary, the (automatic) tensioning roller should be rotated counterclockwise until both pointers align.

Thank you for all the helpful suggestions. There's always more to learn.

The pump itself is now working correctly, and without the pump connector and with the shut-off valve against terminal 15 closed, the car runs well and starts as usual.
"Due to the lack of feedback from the shut-off valve and the preset value, there is a permanent error stored in the memory. As long as you drive normally, it doesn't cause any problems other than the warning light."
Tomorrow morning at 8:00 AM, I have an appointment with the Bosch service center because VOLVO couldn't help me. I can't plug in the connector, so error deletion isn't possible. My last hope is now adjusting the injection timing using a clock.
I will report...

Oops.
"The newer five-cylinder engines are different from the older ones like the AAT and others. It's good that someone noticed that."
Christian.

I believe my engine is the AEL engine from VW/Audi. This engine was used in the Audi 100 and A6.

Etzold's repair manual doesn't distinguish between AAT and AEL when it comes to adjusting the injection timing. However, it's mostly correct for the AAT. Either Etzold overlooked the procedure you described, or the fact that the AEL has TWO tensioning rollers, or the ACV is different for AAT and AEL in this regard.

Christian.

Do you have a book? Could you please tell me the ISBN number and the price?

Otherwise, I'm not sure which Audi/VW engine code my engine has. I also think that VOLVO probably made some changes as well.

Happy holidays... maybe BOSCH will bring me something special tomorrow.

Hey, funny guy...

If you type the word "BOOK", a link related to it appears immediately .

Book book book

Hi, definitely, the Volvo has a cylinder head from a VW Bus, part number [insert part number here].
starting with 074 103 373B. Has a counterpart at Audi (number 0461033).
73...) completely different shape on the valve cover side. The engine block is identical to the one used in Audi models, but it has different pistons and connecting rods.
The mechanical setting value for the ESP is 0.55.
Do you now have a tensioning pulley and a redirecting pulley, as I described?
Best, Jan.

Okay, I have the roles.


This morning at 8:00 AM, Bosch service arrived... Everything was checked, the dial indicator was used and adjusted, the error code was cleared with "ESI," and everything is working .

So, the BOSCH service is delivering the Christmas presents...

Merry Christmas and a Happy New Year.