Seicento Project FS Sei

[M21MFS]

Thanks fella. Within the law we can take it a quick blast on way to the test centre which is our plan. Bit of dualler (which we did last time but that was the night before!)

Dont wanna get my hopes up but yeh...lambda will hopefully be our cure.

 

[M21MFS]

Nuff said

 

[blu73]

i assume its got fresh oil, filter and air filter..? probably says in this thread already somewhere.

I'd check the exhaust for a small blow somewhere before anything else.

 

[fingers99]

Fresh plugs, too, can make a lot of difference -- and get the car well hot before taking it in (you want the cooling fan to come on at least twice).

 

[mrcinquecento]

Genuinely stumped on this, even when something is done and appears to have made a positive difference, something new pops up.

Engine itself was running absolutely fine when we worked on it almost 2 weeks ago. Firstly it was idling high, then i discovered a vacuum leak on the map pipe, changed that and the idle dropped down to normal levels. Car sat idling perfectly for about an hour, revved up etc perfectly, returned to natural idle perfectly. Then we took it for a test run, all seemed absolutely fine until it cut out, then when restarted it was hunting a bit. Playing around with vacuum hoses seemed to momentarily smooth things back out again, so i suspect there is still a vacuum leak somewhere... perhaps confusing map sensor?

Anyway, it went on for the mot, lambda reading was as earlier in the thread, the only thing it failed emissions on. Lambda sensor changed and now it not only fails on the lambda, but co levels have tripled? Confused as hell is an understatement. especially as lambda getting changed seemed to have sorted the hunting (going on video i saw of car, haven't had a chance to see it in person again since tests, but it had certainly smoothed out from when i left it)

Car has been serviced, new pretty much everything (i believe cat was new when fitted), coolant temp sensor replaced, map replaced, timing checked and redone anyway when water pump was fitted, so we know 100% that is fine. Lambda replaced, only thing i can think of still is that gut feeling of a vacuum issue somewhere, but not convinced that is the cause of the emissions, unless there's something else i'm not thinking of outside of the map getting confused by it if indeed there is?

 

[blu73]

check for leaks around the base of the TB. and like i said tiny little hole in the wrong part fo the exhaust can send emissions way off at the back. Fresh plugs will defo help no end if they aren't new - worth whipping out to see what they look like, give them a clean too (every little helps lol).

 

[lkc]

i assume its got fresh oil, filter and air filter..? probably says in this thread already somewhere.

I'd check the exhaust for a small blow somewhere before anything else.

oil change and filters done before original mot

Fresh plugs, too, can make a lot of difference -- and get the car well hot before taking it in (you want the cooling fan to come on at least twice).

Car had been run for at least 30 minutes before and right up to the test and the fan came on several times during the test. I may be wrong but I suspect the tester ran it for longer than he should have

Actually by the end of things there was the tester, M60TYN, myself and the supervisor all watching on to see if Yellow was going to pass. 2 of us praying to the gods of all things Fiat, the tester who knows and the supervisor probably just wanting us out the way. They were nice enough to chat to us afterwards and offer advice though

Genuinely stumped on this, even when something is done and appears to have made a positive difference, something new pops up.

Engine itself was running absolutely fine when we worked on it almost 2 weeks ago. Firstly it was idling high, then i discovered a vacuum leak on the map pipe, changed that and the idle dropped down to normal levels. Car sat idling perfectly for about an hour, revved up etc perfectly, returned to natural idle perfectly. Then we took it for a test run, all seemed absolutely fine until it cut out, then when restarted it was hunting a bit. Playing around with vacuum hoses seemed to momentarily smooth things back out again, so i suspect there is still a vacuum leak somewhere... perhaps confusing map sensor?

Anyway, it went on for the mot, lambda reading was as earlier in the thread, the only thing it failed emissions on. Lambda sensor changed and now it not only fails on the lambda, but co levels have tripled? Confused as hell is an understatement. especially as lambda getting changed seemed to have sorted the hunting (going on video i saw of car, haven't had a chance to see it in person again since tests, but it had certainly smoothed out from when i left it)

Car has been serviced, new pretty much everything (i believe cat was new when fitted), coolant temp sensor replaced, map replaced, timing checked and redone anyway when water pump was fitted, so we know 100% that is fine. Lambda replaced, only thing i can think of still is that gut feeling of a vacuum issue somewhere, but not convinced that is the cause of the emissions, unless there's something else i'm not thinking of outside of the map getting confused by it if indeed there is?

car was hunting again when we were parked up outside the garage but cannot actually remember if it was doing so in the shed. It was certainly hunting throughout the test so whether or not that would affect the test result I bow to the knowledge of those who know far, far more about engines than I*



*not difficult really

 

[M21MFS]

Right to recap on the above. Since taking on yellow we've replaced/investigated:

TB (swapped with the unit from FiaSco as yellows may have been erroniously (sp) adjusted)
Lambda Sensor
Spark Plugs
Air Filter
Waterpump (replaced and timing re-done accordingly)
866 cam removed and shims and cam from FiaSco fitted
Coolant Temp sensor replaced with the unit from FiaSco

As Mark said, the vacuum pipe on the map was causing a bit of grief but that was checked and replaced.

One pattern I have noticed is that the hunting won't kick in from the off. Even today, having not started in a few days, he idles fine when first started. It's only after a proper drive the hunting kicks in.

Today I also didn't notice the car smelling so rich. Hence I genuinely started thinking we'd done it. That said, this cutting out is another regular pattern. Slowing down today to take a left turn on the way to the MOT I lost power pull off of the road. Caught it and managed to bump start him back into life, but I'm just wondering if this is more of a connection than simply a fecked battery (which we know we have)

The only bit of the exhaust which doesn't appear to be new is the backbox (which doesnt even look all that bad) and the only engine parts I don't think we've replaced (with new parts) would be HT leads and the coils.

Quite honestly I don't know what we're going to do next though. It's fine having a list of things to check and replace but again without knowing that the emissions are on the way down we could end up just throwing parts at it for the sake of it.

 

[fingers99]

I'd think so. On the SPI cars most of the pipes to the TB are suspects (best check for right order, too), plus the TB (or the IAC on the TB) itself, the big, fat brake servo pipe ot the gaskets at the base of the TB. Over tight throttle cable can have the same effect. It's just a matter of testing everything out.

Just a thought -- after you've found the leak -- any difference if you replace with the original lambda?

 

[ycming]

Try a different crank sensor, as that could cause it to cut out randomly. And it may fix the hunting issues. If you got a spare engine you would have a spre crank sensor.

Fix that cutting out before retest.

 

[mrcinquecento]

Try a different crank sensor, as that could cause it to cut out randomly. And it may fix the hunting issues. If you got a spare engine you would have a spre crank sensor.

Fix that cutting out before retest.

worth a shot, half considered crank sensor but it seemed too erratic a problem, especially as the cutting out then hunting came from nowhere and seemed to sort with new lambda (thought it appears it returned en route to test if what i hear is correct).

there's a spare, so yeah, worth a try for sure whilst the vacuum hoses are being checked out too.

 

[M21MFS]

Try a different crank sensor, as that could cause it to cut out randomly. And it may fix the hunting issues. If you got a spare engine you would have a spre crank sensor.

Fix that cutting out before retest.

A remarkably good shout, ta.

I completely forgot, but the old Bravo HGT I had did the same. And I remember that getting much worse at the whole cutting out thing!

Original sensor, it turns out, may have be universal. We've just fitted bosch so I dunno. If its still in the shed (which I'm 99% sure it will be) then we know it'll take 30 seconds to try

 

[ycming]

If this is hunting or cutting out once warmed up, I am pretty confident is the crank sensor playing up.

Also does it cut out when you come off gas as rev drop or just randomly?

 

[M21MFS]

It's cut out twice on me, Ming. Both times when braking for a roundabout/junction. I suspect both times whilst on brake and clutching.

 

[mrcinquecento]

It's cut out twice on me, Ming. Both times when braking for a roundabout/junction. I suspect both times whilst on brake and clutching.

the time it cut out on me was under braking too, remember, slowing down for that tight downhill corner in the compound

I'm thinking we're onto something with the crank sensor niggles

 

[M21MFS]

Yeh, that's right. So definately a pattern forming.

Crank sensor is looking like being one of the quickest and easiest ways to get to the bottom of the hunting issue, thats for sure.

 

[Frosty1961]

I suspect many many crank sensors have been tossed because of connector problems...fitting "new" ones might seem to resolve the issues for a bit purely because the connector was disturbed..in any event crank sensor issues will be accompanied by a sudden drop to zero on the rev counter...if it still reflects a proper rpm reading coinciding with what the engine is actually doing look elsewhere...

 

[M21MFS]

The honest answer to the rev counter is im not sure. Was too busy watching traffic and trying to restart lol

 

[adr1ean]

I sorted the hunting on my Spi by dismounting the TB and putting sealant inbetween all of the parts, (the spacer, the TB itself)and replacing the MAP lines as they were old and "crispy". Is the carbon canister on the right way? Double check connections on the filter box, and throtlle body... sometimes the easiest and obvious are to blame

 

[blu73]

crank sensor is good suggestion, they tend to not throw an eml - if they do it tends to log something wrong with a coil due to a misfire or something. Symptoms get worse quite quick under regular use but can seem erratic and weird on something that isn't doing any driving about. They also tend to get worse as they get hotter. Best if you can try one off a known working car over a scrappies special if you don't want to pay full whack for a new one without knowing for sure.