Technical Fiat uno turbo Mk2 not starting

Currently reading:
Technical Fiat uno turbo Mk2 not starting

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi all
Complete newbie to this forum and in desperate need of help .

Got a 1991 uno turbo had this for over 20 years started on the button but unfortunately had a gap where I didn’t start it for 3 years (garaged)
Upon trying to start it in February 2021 I noticed there was no buzzing from fuel pump , so changed this and fuel filter under the bonnet ,
Fuel pump cuts in and buzzes but still would not start engine cranks , did a spark test with a tester and I’m getting full spark ,
I could only put it down to fuel issues so therefore disconnected the fuel pipe that goes directly into the injector rail and put it directly in to a bottle to see if there was any fuel spray , and sure enough the was .

Really scratching my head over this one and thinking the injectors could be blocked ?
Or if you guys could point anything out to check ?

The fuel that was originally in the tank smelt like varnish this was emptied and clean fuel added

Much appreciated guys for help in advance
Thank you
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
From what you have said so far it sounds like that the injectors are the issue.

Have you tried to remove and injects and squirt that into a jar?

Would suggest you do this for all four injectors. Just one or two not functioning correctly would cause a non/bad start.

Also after attempting to start take the spark plugs out and inspect. Are they wet/damp/smell of fuel?

Your worst case scenario would be that the engine ECU has packed up. There is also the lesser expensive possibility that there is an "ignition/spark" control module between the ECU and the spark plugs.

I don't think I have the electric circuit diagrams for an Uno Tubo of that era so am unable to advise on the ECU / Ignition / Injection stuff in any detail.
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi s130
Thanks for your knowledge the plugs are dry I did anticipate the injectors as next port of call .

Are the easy to remove ?

I thought of idea not sure if it would work though
I wanted to disconnect the fuel hose going to the injectors and squirt maybe some some injectors cleaner rigged to a compressor to maybe clean them to taking them out ?
I’ve heard some horror stories of snapped injectors??

Also do you have a picture of the part that could of malfunctioned in between the ecu ?

Thank you so much for your help
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
To my knowledge most / all? snapped injectors occur on direct injection diesel engines when the injector is screw directly into the combustion chamber where it is subject to heat, high pressure and contamination and crud.

On a fuel injected petrol engine then often the injector is just retained in place by a securing clip where the injector plugs into a rubber sealing ring on the inlet manifold just in front of each of the cylinder intake ports.

Looking in my Haynes Fuel Injection Technical Guide then the Uno Turbo and Croma Turbo use the LE2 Bosch LE-Jetronic system. Fuel injection pressure is around 35 psi and the diagram shows the injectors fitted as I described above. Also states "the injects must have thermal insulation to avoid hot start problems" so this also supports them being basically pushed into a rubber mounting grommet and simply retained.

Also the injector needle only moves by 0.15mm when energised so we are talking very small clearance values and thus good possibility that the injectors are gummed up / stuck.

Hope this helps.
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi s130

Thank you so much for taking the time in helping really much appreciated,

Your knowledge is truly helpful

Il have a go at removing injectors but before I do this I have a noid light and will check if current is getting through

One thing I forgot to mention is that I found very strange not sure if this is a linked start problem ,
I noticed the fuel gauge is erratic bascically gos from zero to full tank then midway back to full then zero when ignition is on ??

Many thanks
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi s130 would the injectors be easy to remove or do I need a specific tool ?
Would it be worth buying new injectors as I do recall the car had problems when it was running a year or two ago noticed from hot would take ages to start ??
Thank you
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
See: and scroll to time 2:44.

You will see that the petrol injectors simple plug / twist into manifold and are located under and held in place by the fuel rail.

There is a lot of visual info on the injectors etc. so certainly educational.

I would first get the injectors out and examine them, 'O' rings etc. and test coil continuity. Of course new injects will do no harm but if they are OK and the problem is elsewhere then you have additional expense!
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi s130
Thank you so much for link to the video I will definitely take a look and learn something,

I’m trying to source a Bosch original fiat injectors kit (gromits etc )
Would you know if this would be suitable ?

https://www.ebay.co.uk/itm/11154085...b7tu9-ps1s&var=&widget_ver=artemis&media=COPY

Found this on eBay but not too sure if they would fit the standard L2 injectors?

Any ideas on the fuel gauge problem ?

Also loving the strada abarth love these cars 💪👍
Would love to get one of these also 👌
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
I can't comment on what kit would be suitable. You could try contacting a reputable UK company directly and see what they come up with.

https://www.turbonoz.co.uk/ ???

The original P/N: for injector is: 7626715 - previously P/N:60513338

This appears to be a

BOSCH 0 280 150 702 Injector
OE 60513338
Petrol Injection
Article number: 0 280 150 702

BOSCH 0 280 150 702 Injector
OE 7626715
Petrol Injection
Article number: 0 280 150 702
(Submit a review)

This should be all the info you need to source the correct kit (I hope :) )

Pass on fuel gauge. When it worked normally when the ignition was turned on did it go to max (diagnostic/check kick) and then settle on a correct level? If so then the gauge is probably OK but the sender unit/signal from the tank is at fault.
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
I can't comment on what kit would be suitable. You could try contacting a reputable UK company directly and see what they come up with.

https://www.turbonoz.co.uk/ ???

The original P/N: for injector is: 7626715 - previously P/N:60513338

This appears to be a

BOSCH 0 280 150 702 Injector
OE 60513338
Petrol InjectionArticle number: 0 280 150 702

BOSCH 0 280 150 702 Injector
OE 7626715
Petrol InjectionArticle number: 0 280 150 702
(Submit a review)

This should be all the info you need to source the correct kit (I hope :) )

Pass on fuel gauge. When it worked normally when the ignition was turned on did it go to max (diagnostic/check kick) and then settle on a correct level? If so then the gauge is probably OK but the sender unit/signal from the tank is at fault.
Yes gauge went over to max then 0 and stayed on zero but I had 5 litres of fuel in there surely the needle should move its still on 0 fuel showing ??
Could it actually be the fuel sender itself that’s at fault ?
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Yes gauge went over to max then 0 and stayed on zero but I had 5 litres of fuel in there surely the needle should move its still on 0 fuel showing ??
Could it actually be the fuel sender itself that’s at fault ?
Thank you so much for looking into the parts number etc and sending link over for turbonoz

Il give them a call

I took a look at the video great tutorial 👍
Would you recommend I do a noid test light before removing ?

I’m getting spark at the plugs
Is there anything else electrical I can check other than the ecu to rule out electrical problem on the injectors ie relay fuse etc ?
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
All tests before dismantling are a good way forward. I've personally not had to diagnose a faulty injector / fuel injection system so everything I do is based on experience, hopefully common sense and just my own engineering background and working on cars.

I can only suggest you go with your gut feel and information to hand. Sorry I can't be more specific.

On the fuel gauge when it was last working correctly (if you can remember or detailed in user manual) did the gauge(s) all defect to max and then drop back? If so then I would seriously suspect the tank sender unit and/or the wiring from the sender unit to the dashboard. Could just be a loose or tarnished connection at the back of the dashboard. Some Fiats of that era just had flex ribbon that bent up over a ridge and the connector just pressed over the exposed copper of the flex tape. Not what I would call a real connector connection and as you might guess subject to copper tarnishing, corrosion and wear.
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
All tests before dismantling are a good way forward. I've personally not had to diagnose a faulty injector / fuel injection system so everything I do is based on experience, hopefully common sense and just my own engineering background and working on cars.

I can only suggest you go with your gut feel and information to hand. Sorry I can't be more specific.

On the fuel gauge when it was last working correctly (if you can remember or detailed in user manual) did the gauge(s) all defect to max and then drop back? If so then I would seriously suspect the tank sender unit and/or the wiring from the sender unit to the dashboard. Could just be a loose or tarnished connection at the back of the dashboard. Some Fiats of that era just had flex ribbon that bent up over a ridge and the connector just pressed over the exposed copper of the flex tape. Not what I would call a real connector connection and as you might guess subject to copper tarnishing, corrosion and wear.
I’m thinking more of the sender as the fuel had gone really stagnant .

Il take a look and see what the best option is

On the unos once ignition was turned on it would read straight away the correct amount of fuel .

I’m more drawn to sender unit as my garage is dry and damp free .

Your a star for all the help you have given
I will try have a look at the weekend and post if I fix it

Thanks so much 👍
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi All

Right here goes been having problems on starting my uno ,
Carried out a injector test with noid lights and all pulsing perfectly.
Managed to remove the injectors suspect gummed up injectors.

Now the problem is I can’t replace the injectors as there’s none available so my only hope is to try and get these cleaned ??
Any ideas guys I thought of maybe soaking them in a bath of injector cleaner but I suspect they will be closed and will not clean properly,

Thanks guys any help is appreciated 👍
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
They are available, but pricey

https://www.buycarparts.co.uk/bosch/1150290

Must be able to find cheaper.

As for cleaning I suspect that the gummed parts are on the internal fuel supply chamber. The needle boing closed probably only has a very small contact area not sufficient to stop the solenoid plunger operating.

Put the whole of the injector in diesel fuel and agitate to expel air. Leave for 48+ hours and occasionally agitate. See what rubbish comes out.

Diesel fuel is the soft, non corrosive cleaning option. If that doesn't work then you may have to go more aggressive.

You might be better off getting them professionally cleaned and they will know how to break down and recon the injectors if required.
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Hi s130

Great to hear from you again 👍thank you for the link above I would purchase them but it’s saying out of stock 😬

As for the cleaning that’s a great tip thank you

I also heard that put them into a ultrasonic bath ?
What are you views on doing it this way ?

Correct me if I wrong just thinking of other options
I thought of maybe connecting the injector up to the terminal so it has power and cranking the car and forcing some carb cleaner down the injector ?

Any thoughts

Thank you 🙏
 

s130

Moderator
Staff member
Joined
Dec 5, 2006
Messages
5,334
Location
Wrexham, North Wales
Ultrasonic baths are great, if you have access to one.

Would not suggest attempting to crank the car with inject removed. The fuel rail will put petrol everywhere and you have a risk of fire.

You could connect the injector terminals to a battery to operate the solenoid with the inject full of fluid.

As those out of stock injectors were £116 each then you might as well get a quote for testing cleaning yours. Can't imagine this would cost anywhere near £100 per injector.
 
OP
OP
Vafung19802

Vafung19802

Member
Joined
May 17, 2022
Messages
36
Location
Hertfordshire
Ultrasonic baths are great, if you have access to one.

Would not suggest attempting to crank the car with inject removed. The fuel rail will put petrol everywhere and you have a risk of fire.

You could connect the injector terminals to a battery to operate the solenoid with the inject full of fluid.

As those out of stock injectors were £116 each then you might as well get a quote for testing cleaning yours. Can't imagine this would cost anywhere near £100 per injector.

I’ve managed to source a ultrasonic bath and I’m just currently waiting for them to be cleaned ,

I will let them dry off then I will test them to see if they operate,
seen on YouTube a video on how to test them using a power pack 12v and listening out for a clicking .

Once all are working I will take your tip on a diesel bath for them , one tip too the guy from YouTube said was to use gearbox oil for the injectors as well as diesel .

Il update progress
🤞 hopefully she will start

Also thanks for pointing me to turbonoz managed to get some new seating gro
It’s for the injectors 👍👍
 
Top