Technical Uno pacer 1.4 carb inlet manifold wiring and vaccuum routing

[niamaster]

Hi All,

I'm busy restoring an Uno pacer 1.4 carburettor model 5 door with electric windows. It's been a bit of a challenge since the wiring harness has been hacked one too many times. I'm working at my own pace and deal with one issue at a time.
I'm struggling to figure out the wiring of the inlet manifold sensor and resistor heater see the attached image red highlighted circles. Then the vaccuum highlighted in yellow i managed to get a new one but not sure how to route this to the carb. Any tips or advice will be appreciated. Thanks in advance.

 

[peterdt0260]

Hi All,

I'm busy restoring an Uno pacer 1.4 carburettor model 5 door with electric windows. It's been a bit of a challenge since the wiring harness has been hacked one too many times. I'm working at my own pace and deal with one issue at a time.
I'm struggling to figure out the wiring of the inlet manifold sensor and resistor heater see the attached image red highlighted circles. Then the vaccuum highlighted in yellow i managed to get a new one but not sure how to route this to the carb. Any tips or advice will be appreciated. Thanks in advance.

Did you resolve your vacuum connection on the inlet manifold

 

[niamaster]

Did you resolve your vacuum connection on the inlet manifold

Hi @peterdt0260, I've been a bit busy at work recently and haven't had much time to work on the UNO again, so to answer your question, no I haven't solved the vaccuum routing issue as yet. If you have any tips please share, I appreciate you taking the time out to reply. Thanks

 

[s130]

In your picture the large central manifold pipe assembly has two functions. 1) the larger diameter pipe is for the brake servo vacuum tube 2) the small diameter pipe should have a hose on it going to the item ringed in yellow.

The yellow Item is a thermal vacuum switch. The outlet pipe on this is clearly broken off. A small hose would connect to this and go bank to the carb.

The two terminal switch ringed red is (I believe) the thermal switch that would turn the power on/off to the resistive heater you have ringed in red. On that one lead (green) would go the earth and the other (brown/white) would go the the thermal switch. The other side of the thermal switch would go to +12V fed via the ignition switch.

Can you yell us the part number on the manifold? Hard to read in your photo. With that we can probably find the exact part in ePER and associated drawings.

 

[niamaster]

In your picture the large central manifold pipe assembly has two functions. 1) the larger diameter pipe is for the brake servo vacuum tube 2) the small diameter pipe should have a hose on it going to the item ringed in yellow.

The yellow Item is a thermal vacuum switch. The outlet pipe on this is clearly broken off. A small hose would connect to this and go bank to the carb.

The two terminal switch ringed red is (I believe) the thermal switch that would turn the power on/off to the resistive heater you have ringed in red. On that one lead (green) would go the earth and the other (brown/white) would go the the thermal switch. The other side of the thermal switch would go to +12V fed via the ignition switch.

Can you yell us the part number on the manifold? Hard to read in your photo. With that we can probably find the exact part in ePER and associated drawings.

Hi @s130 , thanks for the detailed explanation, I have attached the images requested. I have also purchased a used thermal vaccuum switch to sort the broken one in the previous image so will try your suggestions and let you know if I succeed.

 

[s130]

I can't find that 7792253 or 7*92253 anywhere either on ePER, another list of parts I have or on the Web.

So suspect it is a casting number and not a Fiat P/N. Was worth a try.

 

[niamaster]

I can't find that 7792253 or 7*92253 anywhere either on ePER, another list of parts I have or on the Web.

So suspect it is a casting number and not a Fiat P/N. Was worth a try.

No stress mate, will defnitely try the routing as per your explanation and feedback

 

[niamaster]

Ok I managed to get the car started and the routing according to your instructions, everything seems to be working as expected just need to sort out the carb tuning. Thanks for all your help @s130 and @peterdt0260 .

 

[s130]

Ok I managed to get the car started and the routing according to your instructions, everything seems to be working as expected just need to sort out the carb tuning. Thanks for all your help @s130 and @peterdt0260 .

Great news!

I'm pleased to have been able to help.