Technical 1996 Punto mk1 176 1.6 petrol elx 90 no start

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Technical 1996 Punto mk1 176 1.6 petrol elx 90 no start

AndrewCas

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Hello,
as above I have a punto 1 1996 1.6 elx 90 5 door hatch.
awhile ago car just stopped running on motorway.AA came said no spark. Got it home to investigate.

I replaced with new coil pack, new leads, new crankshaft sensor. Cranked engine, started first time, ran for about 15 seconds then stopped. Tried to restart, nothing.
tried to hear anything from fuel pump, but couldn’t hear any noise when turning on ignition.
long story short replaced fuel pump, but still no short noise from pump when turning key. Tried starting, nothing.
have included pics of my engine, engine relay,fuses and glove box relay and fuses.
im not sure which is fuel relay or fuel fuse. Have checked fuses all ok. Any help would be appreciated
 

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bugsymike

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Hello,
as above I have a punto 1 1996 1.6 elx 90 5 door hatch.
awhile ago car just stopped running on motorway.AA came said no spark. Got it home to investigate.

I replaced with new coil pack, new leads, new crankshaft sensor. Cranked engine, started first time, ran for about 15 seconds then stopped. Tried to restart, nothing.
tried to hear anything from fuel pump, but couldn’t hear any noise when turning on ignition.
long story short replaced fuel pump, but still no short noise from pump when turning key. Tried starting, nothing.
have included pics of my engine, engine relay,fuses and glove box relay and fuses.
im not sure which is fuel relay or fuel fuse. Have checked fuses all ok. Any help would be appreciated
Have you tried powering the fuel pump via a temporary fused supply to test it?
Reason I asked is one of my daughters had a Grande Punto that wouldn't start and the relay in the fuse box in engine compartment wasn't getting the signal power to activate the relay. In her cars case it was a break in a wire 20mm from the ECU corroded through within the plastic, although a relay itself could be the cause.
 

Frank Folker

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This sounds like a wiring or contact issue. Before replacing any further parts, I would do the "electric refresh". Disconnect battery. One by one pull out all the fuses and push them back in several times to scrape contact surfaces. Same with all relays. Unscrew all the grounds and scrape (screwdriver, sandpaper) the surfaces before screwing the ground wire back on. I attached a photo of all the ground locations from haynes manual (for 1.1 and 1.2 cars but probably very similar for 1.6).
ECU is located between driver and passenger feet behind the carpet, under the ventilation box. If you have a leaky heater matrix it can kill the ECU with moisture. Disconnect the big ECU plug and reconnect it a few times to scrape the contact pins.
Do the same with all the other connectors you can find in the engine bay and throughout the car. I made a small tool for poking and scraping female connector ends - a paperclip with one end straightened and flattened with pliers (essentially a very small file), pliers left a rough surface ideal for the task.
Apply a bit of silicone grease on the rubber seals of connectors to make it easier to plug them back in without damage to the rubber and to aid in sealing. Regular petroleum based greases might damage rubber in the long term.
This procedure takes time and patience but kt resolved lots of weird issues on my own cars and I recommend it for any old car exhibiting random electrical problems. Of course, if some wire is broken somewhere or if some part actually failed then you're in for more investigating but this is a good start and costs nothing besides wasting time.
 

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AndrewCas

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Have you tried powering the fuel pump via a temporary fused supply to test it?
Reason I asked is one of my daughters had a Grande Punto that wouldn't start and the relay in the fuse box in engine compartment wasn't getting the signal power to activate the relay. In her cars case it was a break in a wire 20mm from the ECU corroded through within the plastic, although a relay itself could be the cause.
Hi havnt tried as yet, will poss give a try thks
 
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AndrewCas

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This sounds like a wiring or contact issue. Before replacing any further parts, I would do the "electric refresh". Disconnect battery. One by one pull out all the fuses and push them back in several times to scrape contact surfaces. Same with all relays. Unscrew all the grounds and scrape (screwdriver, sandpaper) the surfaces before screwing the ground wire back on. I attached a photo of all the ground locations from haynes manual (for 1.1 and 1.2 cars but probably very similar for 1.6).
ECU is located between driver and passenger feet behind the carpet, under the ventilation box. If you have a leaky heater matrix it can kill the ECU with moisture. Disconnect the big ECU plug and reconnect it a few times to scrape the contact pins.
Do the same with all the other connectors you can find in the engine bay and throughout the car. I made a small tool for poking and scraping female connector ends - a paperclip with one end straightened and flattened with pliers (essentially a very small file), pliers left a rough surface ideal for the task.
Apply a bit of silicone grease on the rubber seals of connectors to make it easier to plug them back in without damage to the rubber and to aid in sealing. Regular petroleum based greases might damage rubber in the long term.
This procedure takes time and patience but kt resolved lots of weird issues on my own cars and I recommend it for any old car exhibiting random electrical problems. Of course, if some wire is broken somewhere or if some part actually failed then you're in for more investigating but this is a good start and costs nothing besides wasting time.
Thanks very much I will do all that first over the next few days.
 

bugsymike

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Also, do you happen to know, from my pics, which is the fuel relay, and fuel fuse? I can’t seem to find anything that resembles mine, especially engine bay
I don't know off hand , I am sure there will be be a member here with that.
I would get someone to turn ignition on and off whilst you rest your fingers on the relays, usually you can feel it click if activating . Most basic relays have a larger main power terminal in which should test live with a voltmeter and one the same size opposite to power the pump or whatever the relay is for(headlights etc) the other two terminals, usually smaller are an earth and a power to trigger the relay solenoid. Many relays have the information written on them.
Once you locate the correct relay if you have a fused power test probe (a cheap useful bit of kit) you can power up the output side and hopefully activate the pump etc. Note to avoid damage do use a fused test probe.;)
 
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AndrewCas

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I don't know off hand , I am sure there will be be a member here with that.
I would get someone to turn ignition on and off whilst you rest your fingers on the relays, usually you can feel it click if activating . Most basic relays have a larger main power terminal in which should test live with a voltmeter and one the same size opposite to power the pump or whatever the relay is for(headlights etc) the other two terminals, usually smaller are an earth and a power to trigger the relay solenoid. Many relays have the information written on them.
Once you locate the correct relay if you have a fused power test probe (a cheap useful bit of kit) you can power up the output side and hopefully activate the pump etc. Note to avoid damage do use a fused test probe.;)
Thks I’ll check it out
 

Frank Folker

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Relays have numbered pins, a small (sometimes barely visible) number is printed on the bottom of the relay next to corresponding pin. You can use this to know what you're testing for.
Pins 85 and 86 are for relay coil, you need 12v across them to activate the relay and hear the click (relay would work with somewhat less than 12 too but since car's electrical system is 12v, that's what relay gets). So measuring voltages in socket, one will be ground and other +12v when relay is supposed to be powered up.
Pins 30 and 87 are for power sent to whatever is controlled by relay - headlight, pump, horn...
Relay can be controlling either ground or plus side of the load, so sometimes pin 30 is gnd and sometimes +12v. Pin 87 is "normal open" (NO) and gets internally connected to 30 if you power on the relay (by applying power across pins 85 and 86) and then the current can flow to the load.
There is an optional fifth pin labeled 87a which is "normal closed" - the opposite of 87. It is connected to 30 when relay is off and disconnected when on. Sometimes fiat relays have 2 pins 87 instead of 87a, as if they were internally spliced together so don't let that confuse you, read the small numbers carefully.

This way you can measure voltages in relay socket and determine if the power is applied where and when it should be and also you can know which relays are pin-compatible and can be swapped around if you have a suspect one.

Also, a relay can appear functional (clicking when power applied) but internal contacts can be very corroded due to age or humidity ingress and prevent conduction of high current, i had that situation once. So if you want to be sure a particular relay is in good working condition, get something like a headlight bulb (55w) or other somewhat powerful load and see if it works as it should through pins 30 and 87 when relay is powered up
 
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AndrewCas

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Relays have numbered pins, a small (sometimes barely visible) number is printed on the bottom of the relay next to corresponding pin. You can use this to know what you're testing for.
Pins 85 and 86 are for relay coil, you need 12v across them to activate the relay and hear the click (relay would work with somewhat less than 12 too but since car's electrical system is 12v, that's what relay gets). So measuring voltages in socket, one will be ground and other +12v when relay is supposed to be powered up.
Pins 30 and 87 are for power sent to whatever is controlled by relay - headlight, pump, horn...
Relay can be controlling either ground or plus side of the load, so sometimes pin 30 is gnd and sometimes +12v. Pin 87 is "normal open" (NO) and gets internally connected to 30 if you power on the relay (by applying power across pins 85 and 86) and then the current can flow to the load.
There is an optional fifth pin labeled 87a which is "normal closed" - the opposite of 87. It is connected to 30 when relay is off and disconnected when on. Sometimes fiat relays have 2 pins 87 instead of 87a, as if they were internally spliced together so don't let that confuse you, read the small numbers carefully.

This way you can measure voltages in relay socket and determine if the power is applied where and when it should be and also you can know which relays are pin-compatible and can be swapped around if you have a suspect one.

Also, a relay can appear functional (clicking when power applied) but internal contacts can be very corroded due to age or humidity ingress and prevent conduction of high current, i had that situation once. So if you want to be sure a particular relay is in good working condition, get something like a headlight bulb (55w) or other somewhat powerful load and see if it works as it should through pins 30 and 87 when relay is powered up
Thanks very much I’ll also give these a try, much appreciated
 

freemangt3

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One thing for you,
When cranking do the engine revs show on the rev gauge, as the engine needs to see engine speed prior to the fuel pump relay been engauged, also make sure you havent tripped the fuel cut off located next to passenger seat
 

Liquid Knight II

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Sep 6, 2017
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735
Have you checked and cleaned your earths? Whenever I have an electrical issue with a Fiat it's the first thing I check.

ECU earth especially this time of year.
 
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AndrewCas

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One thing for you,
When cranking do the engine revs show on the rev gauge, as the engine needs to see engine speed prior to the fuel pump relay been engauged, also make sure you havent tripped the fuel cut off located next to passenger seat
Havnt checked that yet, been working will have a look tomorrow thanks
 
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AndrewCas

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This sounds like a wiring or contact issue. Before replacing any further parts, I would do the "electric refresh". Disconnect battery. One by one pull out all the fuses and push them back in several times to scrape contact surfaces. Same with all relays. Unscrew all the grounds and scrape (screwdriver, sandpaper) the surfaces before screwing the ground wire back on. I attached a photo of all the ground locations from haynes manual (for 1.1 and 1.2 cars but probably very similar for 1.6).
ECU is located between driver and passenger feet behind the carpet, under the ventilation box. If you have a leaky heater matrix it can kill the ECU with moisture. Disconnect the big ECU plug and reconnect it a few times to scrape the contact pins.
Do the same with all the other connectors you can find in the engine bay and throughout the car. I made a small tool for poking and scraping female connector ends - a paperclip with one end straightened and flattened with pliers (essentially a very small file), pliers left a rough surface ideal for the task.
Apply a bit of silicone grease on the rubber seals of connectors to make it easier to plug them back in without damage to the rubber and to aid in sealing. Regular petroleum based greases might damage rubber in the long term.
This procedure takes time and patience but kt resolved lots of weird issues on my own cars and I recommend it for any old car exhibiting random electrical problems. Of course, if some wire is broken somewhere or if some part actually failed then you're in for more investigating but this is a good start and costs nothing besides wasting time.
All solved now. It was a wiring issue in the engine bay, with multiple wires frayed and corrosion, hidden under tape, causing no voltage to get through to pump and some other things. Shown with red was where the wires were corroded.
thks everyone for your input
 

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chesh

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401
Hi all
I seem to have the same problem with my 1.6
No spark only in the morning when cold.
Engine starts and stall, then cranks fine but won't start.
.
I have changed the crank sensor, different coil, the 2 relays of the ignition, fuses and nothing.
If I came back after 1-2 hours, it starts normally!

This symptom was 3 days in a row.
Could it be moisture somewhere?
Unlike the OP, when mine eventually starts, it drives fine with no cuts or stall if its on the road.
 

chesh

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Joined
Dec 19, 2007
Messages
401
Hi all
I seem to have the same problem with my 1.6
No spark only in the morning when cold.
Engine starts and stall, then cranks fine but won't start.
.
I have changed the crank sensor, different coil, the 2 relays of the ignition, fuses and nothing.
If I came back after 1-2 hours, it starts normally!

This symptom was 3 days in a row.
Could it be moisture somewhere?
Unlike the OP, when mine eventually starts, it drives fine with no cuts or stall if its on the road.

Just checked and when there is no spark, there is also no fuel (fuel pump isn't working).
I have changed a different pump, checked the wiring and everything is good.
Sometimes it does start! it's not a wiring issue because if it starts eventually, it never stall or stop on the road.

I have touched the ground cable that goes from the chassis and it's a bit hot when there is no start.
Could be something with it?
 

bugsymike

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Just checked and when there is no spark, there is also no fuel (fuel pump isn't working).
I have changed a different pump, checked the wiring and everything is good.
Sometimes it does start! it's not a wiring issue because if it starts eventually, it never stall or stop on the road.

I have touched the ground cable that goes from the chassis and it's a bit hot when there is no start.
Could be something with it?
No wiring should get hot, it usually means there is a resistance, this stops the full power getting to the starter or what ever is being powered.
So cleaning the terminals and connections then bolting them down securely is a priority.
Whether or not this is related to your starting problem it still needs fixing. Obviously if you have been "flogging it " over and over trying to start then this will put extra load on those leads/wiring so it will make them warm, however any local hot spots is a cause for concern and needs fixing.
Could your starting issue be related to a relay or the power to the relay at the fusebox.
Unrelated , but I had a daughters 06 Grande Punto 1.3 multijet that wouldn't crank the starter or operate the fuel pump, the relay at the fusebox in the engine compartment wasn't getting a signal from the ECU due to the wireing rotted just outside the ECU. It was only when gently pulling on the wire you could see it "stretch" showing it had broken inside the plastic sheathing. Something like that could give an intermittant fault prior to complete failure.
If you know which relay powers the fuel pump you could test it for a signal when not starting or power it up with a fused power probe.
 
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Trying to apply some logic here..

Once running its fine :)


And when it struggles to start..it makes an earth cable get hot (n)


Sounding electrical to me..

Run a jumper cable from motor metal to battery negative... does it make any improvement??
 

chesh

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Dec 19, 2007
Messages
401
I have just removed and cleaned the ground cable from the battery.
Also cleaned the gearbox ground to the chasis that was a bit blue corroded.
Problem seem to be gone for now as it started fine this morning.

Could a bad ground to the gearbox could be the problem to all this?
Because ECU is grounded to a different location on the inlet manifold and it's fine there.
 
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