I have a small basic seicento 899cc, the problem is the car runs fine when cold but after 5mins it stales at low revs and won't start off the key. It has a strong spark so is not electrical, The pump primes ok but when it is warm and i turn in over it won't start, The inital turn fires but feels like no fuel is coming through. If I stall on a hill going down , I can jump it no problem in second gear. I have connected a second battery with jump leads and negitive to an other earth and this still doesn't help. I did run out of fuel a couple of times and brought a lot of sh-t up. but have since changed the rusty tank and fuel filter, i have also tried adding redex to a new full tank of fuel. Does anyone have a sugestion. I have also changed the coolent sensor,
P.S After turning over for a few (lot) of time I can't smell fuel which leads me to fuel problem but runs ok if bump started down hill again cuts out at low revs.
I'm thinking the injector maybe clogged but whats throwing me is the fact it runs from a bump start
Any help PLease :bang:

Did you replace the right temp sensor (usually colour coded blue, on the inlet manifold)?

at right side of carb blue yes

I have checked and their is only one temperture sensor top of the thermastat housing and yes it is blue and I have changed it. Again the fault is when warm it cuts out at idle and won't start by turning it over but will with a bump start in second gear no problem but i need to keep the revs slightly highier. If I leave it for 5 mins it will start ok by key and run ok for a short time again. It does seem to be temp faulty but got me.:bang: only other thing is when sitting in car with revs slightly high for 10/15mins i can't remember the fan kicking in at any point. Got to be someone their with an answer please help:worship:

There is another sensor on the head, to the left side of the throttle body when looking at the car from the front. I think this is what the guys on here think is the issue.

This is an image from the HG guide, I believe it is the sensor the purple arrow points to between the two crosses..

https://www.fiatforum.com/attachment.php?attachmentid=73381&d=1265049357

Looking up this sensor it only controls warning light or temp gauge if fitted. Don't see how this would effect idle speed when warm.

i,m having exactly the same prob with my 900cc seicento,,,i have tried a swap on the cts but no joy.i have noticed that when i blip the throttle it runs on a little,,maybe a couple of seconds,,before settling down to idle speed.a little short on power ,,i feel also..i shall swap air temp sender next but first i shall spray some carb cleaner around throttle body to check for induction leaks.
p.s
the legendary lada site guru has suggested this tip ,,and he does know his stuff.
dont bang your head moon ,,chill, it will be sorted eventually

Grab a meter and check that the temp sender fitted is giving the correct readings, however......

Check the lambda/O2 sensor. it only comes into play when warm and can cause some strange things to happen to fuel if its getting the wrong idea.

Is the exhaust intact?

Cheers

D

moonxx said:

I have checked and their is only one temperture sensor top of the thermastat housing and yes it is blue and I have changed it. Again the fault is when warm it cuts out at idle and won't start by turning it over but will with a bump start in second gear no problem but i need to keep the revs slightly highier. If I leave it for 5 mins it will start ok by key and run ok for a short time again. It does seem to be temp faulty but got me.:bang: only other thing is when sitting in car with revs slightly high for 10/15mins i can't remember the fan kicking in at any point. Got to be someone their with an answer please help:worship:

Click to expand...

This is maybe a long shot...i remember having this kind of issues with my old alfa v6 and had different garages looking at it and nobody could find a fault till the day that i decided to change the cam sensor. I dont know if your car has a cam sensor but maybe is worth double checking that and lambda sensors too. Hope this helps

rallycinq said:

Grab a meter and check that the temp sender fitted is giving the correct readings, however......

Check the lambda/O2 sensor. it only comes into play when warm and can cause some strange things to happen to fuel if its getting the wrong idea.

Is the exhaust intact?

Cheers

D

Click to expand...

Thanks for that I have a meter but not sure how to check temp sender, I also see their is 2 one with a single spade connection left of the injector casing and the other is a two spade connector blue on the themastat coolant housing, Does anyone know what each one controls. i have replaced the two spade block sensor. Will check out the lamba sensor aswell is their any way of testing that.
One more thing when the car stall warm it starts and runs with a bump in second gear fine and if i keep the revs slightly highier run smooth enough but won't idle, also if I turn it over quick and let key go quick it will start sometimes. Any thoughts ???:bang:

rallycinq said:

Grab a meter and check that the temp sender fitted is giving the correct readings, however......

Check the lambda/O2 sensor. it only comes into play when warm and can cause some strange things to happen to fuel if its getting the wrong idea.

Is the exhaust intact?

Cheers

D

Click to expand...

how do I check the temp sender do you know what the reading are.
I also disconnected the lambda at the 4 wire block and started car after it cooled down but cut out again when warm does this mean the lambda is ok or would this happen when it got warm disconnected ?.

Begining to think maybe the temp gauge I replaced is faulty, After trying to start by key and failing i took out number 1 and 3 spark plug just to see what they look like and they were dry but rich black.Please someone help me

It's difficult to read spark plugs at the best of times, but it might suggest it was overfuelling.

To test (blue) thermo sensor, take it out, attach meter on ohm setting, put it in a pan of water -- a thermometer is helpful, but not essential. The resistance shhould steadily decrease as the temperature increases, from something like 10000 ohm at 0 C to around 200 ohm at 90C (put it on the stove, heat gently, don't let the water boil).

A Google will tell you how to test the lambda.

One othher thing that can cause overfuelling is if some muppet has fitted the leads for the injector so badly that the earth one is permanently earthed, but the results are usually very extreme indeed.

It's difficult to read spark plugs at the best of times, but it might suggest it was overfuelling.

To test (blue) thermo sensor, take it out, attach meter on ohm setting, put it in a pan of water -- a thermometer is helpful, but not essential. The resistance shhould steadily decrease as the temperature increases, from something like 10000 ohm at 0 C to around 200 ohm at 90C (put it on the stove, heat gently, don't let the water boil).

A Google will tell you how to test the lambda.

One othher thing that can cause overfuelling is if some muppet has fitted the leads for the injector so badly that the earth one is permanently earthed, but the results are usually very extreme indeed.

I will test temp sensor but think it should be ok as I replaced it last month when this happened and made no difference. I think it must be the lambda sensor
thanks will let you know

Don't think and buy, test and then buy.

Cheers

D

rallycinq said:

Don't think and buy, test and then buy.

Click to expand...

Absolutely. And don't forget -- assuming that your car is throwing a ECU light -- that there is software out there to interrogate the ECU (only for fotuto Windoze, though :bang

fingers99 said:

Absolutely. And don't forget -- assuming that your car is throwing a ECU light -- that there is software out there to interrogate the ECU (only for fotuto Windoze, though :bang

Click to expand...

No there is no ECU light on, goes out after it starts when cold or if running above idle warm

with exactly the same symptoms and problems on my sei ,,checked all sensors on top of engine,,all within range ,,had a squint at the crank sensor,,,it was slightly out of line with the pully and more than 4mm away from the teeth,,,one bolt was missing ,,causing it to twist away from perfect alignment ..cleaned ,,file bracket down until my finger was sore ,,motor is now running sweet,,more power and if it works tomorrow i will consider it sorted...i suggest you have a check of your sensor..£ 26 for a new one or try a scrapper first.but do give it a clean .hope this works for you..

Less thhan that, I think, if you don't buy from FIAT. But I'd not get one from a scrappy, as they're pretty fragile (which is why a lot of people using aftermarket ECUs ditch them and go to hall effect ones).

The "one bolt missing" phenomenon only occurs with 899 cars.............