73 Volvo TPS

I am trying to replace the TPS for my 73 Volvo 1800ES with a 5-pin Bosch # 280 120 047. Is this TPS compatible with the 73 Volvo?

The original Volvo TPS is a 4 pin, no WOT. According to the wiring schema on the 047 TPS, the pin arrangement from top to bottom is
9, 20, 12 (WOT not used), 17, 14.   

Comparing this to a known working 4-pin TPS (not a 047) installed in another ES, the pin arrangement is 9, 20, 14, 17.   

I have installed the 047 TPS according to the schema indicated on the TPS, but I do not get continuity between pins 17 and 14 when I test with my meter. I do not heart any clicks either. Is it possible that the pin arrangement is wrong, and should actually be 9, 20, 14, 17? Should I switch wires 14 and 17, and will this cause any damage?  

Thanks
Mitch
 

On the 047 TPS, which pin controls WOT? Is it 12, or 14?

WOT = wide open throttle (full open)

Hi Mitch,
maybe the 047 doesn't fit at all because it is noticed to be a 'Bendix' type, correct right-turning, almost compatible with a Mercedes type 015 (which is a 5-poled compatible with the 4-poled 026 and the 39 that would fit your car) but with a different mounting direction.
Maybe it won't fit because the idle-switch-position isn't reached at all when you try to adjust the unit.
You have to try this out at first...
Install the switch and turn it to left. You should feel some resistance than. Is it adjustable in this position?
Else it isn't useable at all because it doesn't fit mechanically.

You have to know the Pins 14 and 12 are both 'ground'='earth'.
Pin 2 is the contact you call 'WOT'. But this is incorrect - the contact switches at 2/3 open throttle or 3/4 open throttle - depending on the car model <and sometimes model year>. But you don't need it, that's good - you don't have to care about this.

But try at first what I wrote above.
Then we can think about the wiring. You can't damage anything.
It's only the 'ground' that is switched towards the other contacts in this unit.

Regards
Norbert





 

I am going to try to move the wire at pin 14 to the position for 12. This will result in the arrangement 9, 20, 14, 17, and leaving the last pin without a wire. This will then correspond to the arrangement on the original TPS that is on the other Volvo ES.

If this change doesn't work then I will probably have to find a good working 039 unit.

Thanks

Hi,
please check at first what I wrote above.

I have some good and some NOS '019' and '024' because it's the type used in my Opel.
They are five-poled, but fully compatible to the 4-poled 039 that fits your car.

I installed this 5-poled type once in a 4-poled car, the plug had just to be set to the right side, Pin 2 stays free.
Nothing had to be changed at the wiring.

Therefore you could search for a 019 or 024, too that is almost the same. Used in Porsche 914 and Opel.

Regards
Norbert

Thanks Norbert. I swap the wires as per the schema on noted on the TPS, but now I'm going to try to move them wires as compared to how they are installed on the original TPS. I understand that even so, it may not be possible to adjust it correctly. I will report back.

Good to know that the 024 is also a possible replacement for the 039.

Hi Mitch,
the 019 and 024 are five-poled...

The units I have wear double-numbers.
2+14|17|12+47|20|9

Did you tell us all numbers?

I'm quite sure the wires wouldn't have to be interchanged when you would install a 019 or 024 because I did the install without any probs.

But... don't forget what Volker wrote before. Cleaning and degreasing will help in at least 95% of cases. Maybe you have to bend the 'fingers' or the microswitch a little, but give this a try before you install a part that is definitely not a perfect fit.

Regards
Norbert

Hi Mitch,
once more... I just noticed the numbers you posted are vice versa to those printed on the unit.

Following this, I think I can help you.
I was just a little bit confused because you didn't mention the double-numbers.

The correct order following you scheme from top to down should be:
9|20|12|17 - the pin 2/14 (last pin down) is unused.

Don't care about the numbers 12/14. They are the same, the other number is meant for other cars. Pin 2 is the 'WOT'-pin and has to stay free. don't connect 12 or 14 here but in the third position from the top.
This middle contact of the five is the mass (ground) wire towards the ECU. Connect line 12 or 14 here - you only have one of them.

But maybe the prob is the tps doesn't fit mechanically...

Regards
Norbert

Yes, Norbert, it seems that now it is cleared up.

On the Volvo, we use 14 and not 12. So the correct order from top down is 9/20/14/17 and the last pin is unused. I have connected the pins in this order and I have continuity, and the TPS seems to be working well. The middle pin is 14.

However, I am not able to hear the series of 18-20 clicks when I open the throttle manually. I can't understand why I am not able to produce the clicks.

Thank you for your guidance.

Mitch

Hi Mitch,
just read the signals out.
Read the continuity between Pins 14 and 20 while you open the throttle extremely slow.

Maybe there is another reason for the injector-clicks missing than the tps...

Regards
Norbert

OK, I will try this. Thanks

Between pins 14 and 20 I read 11 continuity beeps when moving the throttle.
Is this less than normal?

It`s working o.k.

Regards
Norbert 

Good to know.
Thank you again for your help Norbert.
Mitch

At idle, are the drag contacts supposed to touch each other? Mine do not touch, but I did adjust the TPS so that the meter reads 0 at idle position.

Hi  Mitch,
I don't understand 'drag contacts'

Regards
Norbert

Maybe you can mark this at the photo I add.