Technical Bravo 1.4 Low compression & Poor cold starting

[Fiatmum]

96 Bravo 1.4sx with new plugs, HT leads , Lambda sensor & new MOT

This is my Son's first car, has the full body kit and looks fabulous… He loves it !

Engine sounds nice and quiet when warm and starts first time most of the time. However, in the morning after we get a frost (-0 Degrees), the car is very poor at starting. It turns over and tries to fire but doesn't quite catch. Sometimes the only thing I can do is start it with the throttle peddle pressed half way down and after a 30- 40 seconds it finally catches. It then struggles at around 1500rmp for the next couple of minutes as if its got a very bad misfire. Once the idling has settled down it drives like a dream..

These are the things we think are ok.....

- Damp, moisture... Cleaned all connections, used WD40, no sparks at night.
- spark plugs and leads (NGK)... We're on our second set to prove it’s not them.
- Intake Air Temp sensor... Resistance reading 0degrees= 5.2KOhms 8degrees= 4K
- Coolant Temp Sensor... Dashboard gauge works ok & resistance V-Cold=5.5K Hot=330R
- New Lambda Sensor... Also, if I hold the sensor in my hand with the ignition on, I can feel the heater begin to warm the plug.
- Ignition coils... resistance Primary= 0.5R Ohms Secondary= 13K5 Ohms

This is what we've now discovered....

- Compression... Cyl 1= 120 Cyl 2= 125 Cyl 3= 130 Cyl 4= 140

Questions…

1. Is this classed as low compression when the Bravo’s done 98000 Miles
2. I’d like to spend £50 on engine oil, engine flush & paraffin and then follow Jug’s previous thread Re: Camshaft And Tappets to clean the pickup pipe & oil flinger bar, but I’m struggling to understand if that will (a). Increase compression & (b) Improve cold starting…. (c) Is it because it oils up the valve shafts so that the valves spring back to their seating more quickly?
3. Will cleaning the oil pipes make a noticeable improvement to the performance as we’ve always thought the car felt “blocked” ( not a bad thing for a sons first car though! )

Any help would be appreciated.

 

[KbH40]

You search in the wrong engine incredible power... i think... :yum:

 

[lownwide]

Fiatmum,

Have you had a look inside the oil cap for white gunk? Sounds like it could be the head gasket on its way out, although the comp test readings aren't vastly different to each other, it could very well be going....

Is it losing any oil or water?

I had a similar problem with my Bravo and it turned out to be the earthing strap on the engine. hooked a jump lead from the battery neg terminal to the block to test it and it started ok, replaced the earth stap and its been fine since.

Good luck!

Lee

 

[lownwide]

BTW,

Which scrapyard did your son fin bits for a Bravo in?

Ta

Lee

 

[Fiatmum]

Fiatmum,

1 Have you had a look inside the oil cap for white gunk?
2 Is it losing any oil or water?
3 I had a similar problem with my Bravo and it turned out to be the earthing strap on the engine.

Lee

1. Oil Cap looks very clean and cam looks oily & shiny.. Looks as good as new.
2. No loss of oil or water. Not had to touch since we got the car 9 months ago, when we did the usual checks and topping up on antifreeze.
3. Already removed & re-filed (cleaned) the earth lead and frame from under the clutch slave cyl, chassis and battery... Also the same for the positive to the starter motor and then on to the alternator.


Letting my trade secrets out now.... We've been using Silverlake at Hedge End, Southampton for spares.. Loads of small but important things like front fog light lense, sunroof seals etc....

We've just fitted a donor battery from my car for testing over the next few days but I'm not holding any hopes on it fixing the cold starting.

We've just checked the wiring from both the intake air temp and water coolant temp sensors back to the ecu. Pins 7,11 and 8,11 respectively all as should be. I was hoping to have found a broken wire on the air intake sensor cabling as the manual says the ecu will default to 20 deg if open circuit. Unfortunately this is not the case.

If you're wondering, Fiatmum is the gopher who types...the He-men in the family are outside playing under the bonnet
Can't have them putting oily fingers over my nice clean keyboard :yuck:

Tracy

 

[fiat_-_bravo]

Cleaning the oil pipes won't do much for power, but makes sure you clean them beacuse they are pigs for blocking and will eat your camshaft and cam follwers.

I keep a set of oil feed pipes in a bath of parafin and i change them when i service the car.

Have you checked the expansion tank with a torch to see if you can see an oily film on the water it is awkward to check inless you have got a torch because of how far down the expansion tank the water is but it does sound like the start of head gasket failure which is a relatevely easy job had to do it on my 1.4

 

[Adrian Bravo]

I had this very problem this morning for the first time.
My sparks plugs where loose and the HT leads where naff one was melted to the block tightened 3 plugs and sprayed with wd40 and it started.

Then went on to change the plugs and leads as they needed doing anyway. It started after a lot of cranking, but I dont know how it will fair tomorrow in the cold. I plan to clean my earth strap, and check the starter brushes.

Your car is a lovely example, id put a hlx wing on the abarath one is a bit too big for me

 

[KbH40]

Tracy thats really awesome looking Bravo!
Its all stock Abarth package, right? I only found here the wing on my 3rd door... And these wheels are the top of the icecream!

Is it 15" or 16" the size? Can you give more pictures of that beauty?... the engine and inside...

I'm inlove

 

[Fiatmum]

Re: Bravo 1.4 Low compression & Poor cold starting...now with video

Outside temp was -2 this morning with frost and Bravo would not start.....
This was after using a fully charged battery (no problems) from a 2.0L Petrol Peugeot 306.

We've taken a video of today’s cold start for all to see. This is typical every morning when cold. It’s taken showing various starts. First couple of starts without touching the accelerator. Next few are with various throttle positions, from quarter to half. The final couple show how easy it is to start after a minute or two of idling. (It chugs away like my little Fiat 500 used to 30 years ago when first bursting into life...though Bravo sounds much better when warmed up!)


Question.
Could blocked oil pipes still cause this problem?

Help :bang:


Also attached are some more pictures. This car is my 17 year old son's pride and joy, saved and paid for on his own. If we lived in Florida, there wouldn't be a starting problem. Unfortunately Dorset is as far south as we'll venture
Wheels are 17’s, Tyres are 205/40R17

Click signature below for car's thread.

Tracy

 

[bridges]

When the car is running at 1500rpm is that you holding it there on partial throttle?

If so it sounds like the CTS sensor The Coolant Temp Sensor is what tells the ecu that the car is cold. It pumps in more fuel and allows the car to run. when the car warms up it leans off the air fuel mix again.

When it fails to operate correctly it tells the car that it is warm. Even when it is cold!! The car does not adjust accordingly and can in some instances struggle to start and will not hold revs unless helped. However once the car is warm it will run fine.

Cyl 1= 120 Cyl 2= 125 Cyl 3= 130 Cyl 4= 140




there is something unusual about this reading.I suspect a faulty compression gauge or some error in the test. was this done on a cold engine?? It looks as if its a cold engine which as it warms is altering the results. As less warm air will fit in the cylinder to cold air which is denser.
the way that it drops by 10 and then 5 psi as each cylinder is tested is odd.
Cylinder 1 and 4 are 20psi different, that is massive.
I would warm the engine up for 10 mins then redo the compression test.


normal results should look the same, a fault in one cylinder should look like,

Cyl 1= 138 Cyl 2= 141 Cyl 3= 114 Cyl 4= 140

just re read your post.. looks like your CTs is working, is it the same one that does the gauge that tells the ecu ??????????

 

[Adrian Bravo]

Thats video is exactly how mine was yesterday.
https://www.fiatforum.com/bravo-brava/174924-injector-reliability-1-4-12v.html

But your engine sounds very very rough once its going. After I sorted the spark plugs it runs very smooth. Comparing it to how it used to be I think my car always had a slight misfire.

Do you know what compression should be I was looking for the figures last night but couldn’t find them.

Once your cars sorted look at getting a panel filter it made mine much sharper, I have K&N.

EDIT: Nice rocker cover by the way i want to paint mine up

 

[Fiatmum]

When the car is running at 1500rpm is that you holding it there on partial throttle?

Yes, if we didn't it would struggle to get to fast Idle for the first 60 seconds.

Cyl 1= 120 Cyl 2= 125 Cyl 3= 130 Cyl 4= 140

there is something unusual about this reading.I suspect a faulty compression gauge or some error in the test. was this done on a cold engine??

No, the compression test was done hot, just after our son came home from work. The gauge is new so I hope it’s accurate. We did all cyls twice and each time got the same reading. We've not done this kind of test before so aren’t too sure what's good or bad. The dials in the gauge only show overlapping indications of good and bad.
0 - 140 Red 110 - 220 Green 200 - 300 Red. We’d be happy for a reading of 180 but accept that the car has done a lot of miles.
My gut feeling is that the low compression is not the main cause of the poor starting unless someone can explain why.

looks like your CTs is working, is it the same one that does the gauge that tells the ecu ??????????

I think so

your engine sounds very very rough once its going.

Yes it is rough for the first few minutes. As if it’s just been sprayed with a hose pipe. Once fast idle has gone down to 850RMP is runs smooth.

Do you know what compression should be I was looking for the figures last night but couldn’t find them.

No we don’t but suspect +150 is good.


Tomorrow we'll try removing the spark plugs to check whether they are wet or dry then disconnect the CTS and Air Intake Temp sensor individually while cold starting (though we’ll have to cut one of the wires for the AITS).

My son has just used the car to go off to work for the afternoon and it started first time with the air temp at +2.
Tends to only be a starting issue in the morning… Damp/Wet!!.... We’ll try some more WD40 tonight before we put the car to bed on the drive.

Keep the ideas coming please, every bit helps, thanks

Tracy

 

[Fiatmum]

Have you checked the expansion tank with a torch to see if you can see an oily film on the water it is awkward to check inless you have got a torch because of how far down the expansion tank the water is but it does sound like the start of head gasket failure which is a relatevely easy job had to do it on my 1.4

We'll check in the morning

Tracy

 

[KbH40]

This problem from the video - I have it too, but its not always...
I discover the problem in lower temperatures, here now is between -5*C and -10*C
And I think the problem is from the ECU , from the sparks or Lambda!
In Monday I'll visit service becouse now no one goes to work for holidays...

My problem is similar, the diferences are that when I start my engine cold and go, my cars turns off when its not in a gear, then the r.p.m. goes to zero quick and my batteries and oil lamps go on!

I stop, remove key and push it back, start the engine... A little like you hard, and with more push it start... After that everything is fine, till next cold starting!

I thing the ECU is making errors because like the electricity goes off and no gasoline, nothing in the sparks...

Sorry from bad English :bang:

 

[Fiatmum]

Tomorrow we'll try removing the spark plugs to check whether they are wet or dry then disconnect the CTS and Air Intake Temp sensor individually while cold starting (though we’ll have to cut one of the wires for the AITS).

Tends to only be a starting issue in the morning… Damp/Wet!!.... We’ll try some more WD40 tonight before we put the car to bed on the drive.

This morning it was -1 again so we tried this in the following order

- Spayed WD40 arround plugs & HT parts (forgot to do it last night)
- No oily film on the water in the expansion tank
- Engine would not start via jump leads from a running Saab 95 TDI
- Removed all plugs and they all looked dry
- Checked cold compression... 1=95 2=98 3=105 4=110
- Disconnected the Engine Coolant Temp sensor CTS with the ignition on and saw the idle linkage on the throttle body move back to its warm position. Reconnected a few times and all looks good. Engine still would not start with it disconnected.
- Cut one of the wires (No1/RHS) to the Air Intake Temp Sensor AITS. Engine still would not start with it disconnected. Remade the connection, checked the reading was back to 5.3KOhms (spot on for -1)
- I'm now sure that both the CTS & AITS are working ok
- Engine still would not start even after switching the ignition off and on a few times, then disconnecting the battery for 20 minutes.
- By now there was a strong smell of fuel so we removed No1 spark plug and it still looked dry.

:idea: Our feeling at the moment is a combination of the following.....

- Only sure way of starting the car is to hold the accelerator fully down.
- Low compression.. Down stroke of the piston is weak hence very little air being drawn in.
- Engine very cold. Hence slow to turn over
- Fuel from throttle body is not being sucked into the cylinder head quicky enough so it's condensing to the walls of the inlet manifold.

We'll remove the throttle body today and have a look inside.
Hubby has also has the idea of removing the intake manifold and cleaning the inside chambers with emery paper. Theory being the same as a dirty windscreen... If it’s dirty it easily attracts condensation. If it’s clean, it won’t.

Tracy

 

[bridges]

have just listened to the video clip. I'm back to thinking compression.
When you do a compression test it is not really the set value you are looking for, it is the readings of one cylinder against the others.
On your readings cylinder 1 is down by 20 psi which is a lot, it is masked by the fact that there is a gradual stepping across the cylinders regarding pressure loss.

When the car is attempting and when it does start, is there much blue smoke from the exhaust, is there much pressure when the oil cap is loosened/lifted with the engine running.

I'm thinking that the car may have poor valve clearences.
1.4's suffer from poor oil lubrication to the upper head via the spray bar, I wonder whether manually oiling the upper engine would alter the starting.
have your compression tests been done dry, try a wet test.

 

[bridges]

You sure the injectors not faulty??

 

[Adrian Bravo]

The single point injection floods very quickly so you quickly go from one problem to another. I know I did.

-1 here this morning too and my car fires perfectly now but I think my starter motor is too slow on the first few turns. So im looking at changing brushes or buying a new one on exchange for £78.00

I think towing mine and bump starting it would prove if the starter is too slow but car is near impossible to steer without power steering

 

[Adrian Bravo]

You sure the injectors not faulty??

Hey bridges. My neigbour said the same look at;
https://www.fiatforum.com/bravo-brava/174924-injector-reliability-1-4-12v.html

Yesterday I was told the 1.4 injectors have no reliability problems and my cars fine once started. Still cant be sure mind.

The youtube video, I have listend to it lots of times and if my 1.4 went from its current sound to that honestly id be very worried.

 

[ChrisUK]

When I listened to he vid after you got it going it does sound likes its starved of oil, although Im not sure if thats causing the starting problems. I'd still do jug's guide as if it is getting starved of oil it can lead to a excessivly worn camshaft and even seize if it gets very bad.