1800: P1800ES fuel injection

[Laird Scooby]

Originally Posted by Ron Kwas

LS;

I briefly compared your description with my detailed contact/function drawing here:

Source: https://www.sw-em.com/bosch_d-jetronic_injection.htm
...it does look like the function you have observed is correct, but you might want to double check it against the detailed drawing and note out any inconsistencies or questions.

Good Hunting!

Bit baffled Ron - i was referring to the Thermo Time Switch connections above, unless you're thinking of something else?

[VolvoRoyS]

Well on that picture wire no. 9 is at the top and 17 at the bottom as I am finding.

Roy

[VolvoRoyS]

Think I might have caused some confusion by talking about both the wiring for the cold start valve and TPS issues in this fuel injection thread

Roy

[c1800]

Hi Roy, I don’t know why Ron’s pics show #9 at the top. I rechecked my TPS, clearly has 17 on top, next 14. I hesitate to move the wires around to identify the others, given their age.

Also screen shot from the Fault tracing manual previously posted also has 17 on top.

I checked the parts book and the same TPS part number is shown for all 1800’s, 70-73, 243366.

There are many applications for the Djet system , with corresponding similar looking, but different components. There was a listing for “Classic Bosch” D-Jet parts online, but that was taken down by Bosch several years ago.

UPDATE: Upon further investigation, I removed the cover on my TPS, it appears Ron’s picture, and my TPS are different. I can’t find a part number on mine.
It looks like you’ll need to confirm which one you have.

Ron’s on the left, mine on the right.

[VolvoRoyS]

Originally Posted by c1800

Hi Roy, I don’t know why Ron’s pics show #9 at the top. I rechecked my TPS, clearly has 17 on top, next 14. I hesitate to move the wires around to identify the others, given their age.

Also screen shot from the Fault tracing manual previously posted also has 17 on top.

I checked the parts book and the same TPS part number is shown for all 1800’s, 70-73, 243366.

UPDATE: Upon further investigation, I removed the cover on my TPS, it appears Ron’s picture, and my TPS are different. I can’t find a part number on mine.
It looks like you’ll need to confirm which one you have.

Ron’s on the left, mine on the right.

Thanks for going to the trouble of taking yours apart! Presumably it's one held together by screws? Are you saying that the no. 17 is stamped on the top of the switch body and lines up with wire 17 because on my switch the no. 17 is stamped at the bottom of the switch body and lines up with wire no. 9. I'm beginning to think that the one on my car has been replaced by one that is not compatible with the wiring. Would it do any harm to the ecu to change the wires around and try it out?

Roy

[c1800]

Originally Posted by VolvoRoyS

Thanks for going to the trouble of taking yours apart! Presumably it's one held together by screws? Are you saying that the no. 17 is stamped on the top of the switch body and lines up with wire 17 because on my switch the no. 17 is stamped at the bottom of the switch body and lines up with wire no. 9. I'm beginning to think that the one on my car has been replaced by one that is not compatible with the wiring. Would it do any harm to the ecu to change the wires around and try it out?

Roy

Yes, my TPS has a screw on cover. After some less than definitive searching online, it appears that there are at least 2 different TPS used. One with a screw on cover and one with a snap on cover. The one in Ron’s pic appears to be the snap on model. Which one do you have? In my searching there were some clues that the screw cover is an early model, and the snap on is a later model. The screw cover model on mine doesn’t have any terminal numbers on the cover.

I don’t have any advice about switching your wires. To determine the bosh part number of your TPS you’d have to remove it, the number is on the back. I do know that you can run with the TPS disconnected. Try this, and see what happens.

In several listings on line, like this one, the Bosch part number is listed as 0 280 120 039.

https://fuelinjectionproducts.com/pr...800e-se-series

That link also indicates “ MAYBE REPLACED BY BOSCH 0 280 120 026”. Don’t know the part number on mine, I spent some time setting it up properly a while ago, don’t want to remove it and do that again.

[VolvoRoyS]

Originally Posted by c1800

Yes, my TPS has a screw on cover. After some less than definitive searching online, it appears that there are at least 2 different TPS used. One with a screw on cover and one with a snap on cover. The one in Ron’s pic appears to be the snap on model. Which one do you have? In my searching there were some clues that the screw cover is an early model, and the snap on is a later model. The screw cover model on mine doesn’t have any terminal numbers on the cover.

I don’t have any advice about switching your wires. To determine the bosh part number of your TPS you’d have to remove it, the number is on the back. I do know that you can run with the TPS disconnected. Try this, and see what happens.

In several listings on line, like this one, the Bosch part number is listed as 0 280 120 039.

https://fuelinjectionproducts.com/pr...800e-se-series

That link also indicates “ MAYBE REPLACED BY BOSCH 0 280 120 026”. Don’t know the part number on mine, I spent some time setting it up properly a while ago, don’t want to remove it and do that again.

The TPS on my car is the snap on model and yes the number on the back is 0 280 120 039 and looks like the one in that link you included. The numbers 17, 14, 20 and 9 appear both on front and back of the TPS where the plug enters and I can just see some numbers on the one in that link. There is also the number 12; it's a bit hard to explain but the 14 and 12 nos are between 20 and 17 and above one another suggesting that 17,12,20 and 9 is another acceptable fit. I think I will try swopping the wires around to match up and see what happens.

I have now managed to swop the wires and can report that engine response to the throttle is much improved. Although previously the engine would idle ok (after I re-soldered wire 17) as soon as I touched the accelerator pedal the engine would try to stall and only a boot full of throttle would keep it going. Now I can tread gently on the accelerator pedal and the revs rise gently in response so conclude that the wiring was wrong. It must have been like this for years and could well be the reason the previous owner put the car into the auction with no reserve. I have driven it round the block and noticed a vibration and the brakes seem poor, so more work required. Suspect prop shaft needs some attention.

[c1800]

Roy, yes of course having the wires connected in the correct configuration would be the right thing to do, not sure what I was thinking yesterday!

Reading on a Djet forum 12 is not used on Volvo so the correct connection should be 9-20-14-17. Which I assume is how you have them connected now.

Glad you have that sorted. Also it appears that having it connected incorrectly didn’t damage the ECU.

Leaves me wondering why there are 2 different TPS when the parts book only lists one number for all years... I suppose that since Bosch supplied them and they can be interchanged (with the correct wiring configuration) it didn’t need a new part number assigned.

Looking forward to your future reports on sorting out the rest of the car.

[Laird Scooby]

Originally Posted by c1800

Roy, yes of course having the wires connected in the correct configuration would be the right thing to do, not sure what I was thinking yesterday!

Reading on a Djet forum 12 is not used on Volvo so the correct connection should be 9-20-14-17. Which I assume is how you have them connected now.

Glad you have that sorted. Also it appears that having it connected incorrectly didn’t damage the ECU.

Leaves me wondering why there are 2 different TPS when the parts book only lists one number for all years... I suppose that since Bosch supplied them and they can be interchanged (with the correct wiring configuration) it didn’t need a new part number assigned.

Looking forward to your future reports on sorting out the rest of the car.

Something i've found (on the injectors for my 760) is that while the original part number becomes NLA with Volvo, Bosch have a replacement part number. Sometimes Volvo then supply it as the updated version of the same number or a Bosch injection dealer will fit the updated one or some clever article will discover the similarities and do the work themselves to retrofit the later (available) unit.

With my injectors, Volvo didn't offer an alternative. However i discovered that Bosch did and it turned out that the Vauxhall Omega V6 used the same injectors. A quick search of fleabay yielded a set of 6 in good condition.

I don't think you got the Vauxhall Omega in Canada or the USA, it's what we would call a large car but i suspect you would call it medium/medium-large, engines ranged from 2.0 to 3.2V6 and is a similar size and era to the Volvo 940 and was also RWD with a similar range of gearboxes and equipment so would have been a direct competitor to the 940 - there was also a BMW-sourced 2.5 straight 6 diesel version offered.

The purpose of the extra waffle was mainly to show that Bosch have been used on a variety of cars, some of you know that already obviously but intended more to any newcomers to show thinking outside the Volvo box can also work.

[142 Guy]

A bit late returning to the party; but

If I now use the numbers on the switch body the results would be:

9-20 open circuit throughout range and on return
14-9 alternate open circuit/closed circuit with closed at max; on return open
17-9 open circuit throughout range and on return
14-20 alternate open circuit/closed circuit with open at max; on return open
20-17 mostly open circuit; brief closed circuit on initial movement
14-17 closed circuit initially, open circuit on opening throttle

This would be the correct operation of the switch and if you have now aligned the wire numbering so that it matches up with this it should be correct - as your recent driving tests seem to indicate.

The D jet controller wiring diagram provided by Ron K is functionally correct and the pin numbering is functionally correct. I don't know that the numbering represents any kind of correct physical arrangement. Even if it is, as Ron attributes on his website the D jet controller schematic originated from Frank Kerfoot and he did his work on the VW / Porsche 914 version of the controller, so the numbering might be physically correct; but, for the version of the switch used on the VW / Porche.