Technical 1.1 engine low power in low revs

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Technical 1.1 engine low power in low revs

amitoha23

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Feb 25, 2006
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Hi
i have 1.1 sporting engine . 38 mm throttle ,ecu performance chip , k&n air filter , punto 75 cam , for the last 2 months the revs have trouble stabling at ideal revs , and i have lost engine power . the breather blow a lot of air at low revs .
have tested compression and found all four approx 195 psi .

replaced step motor , and cleaned fuel injection system .
at first i thought the engine was dead . but after checking compression i am more confused then before .

need help ,

thank you all
Amit
 
Re: 1.1 engine lack off power

HI
have checked all TB connections.
have replaced 02 sensor ,six months ago .

the rpm sensor (near the pulley ) has faulty readings according to autodata
and will be replaced .
i have replaced over the years all of the sensors except the rpm,map sensor . can they be responsible to the lack off power ?

what about the breather why do it blow a lot oh air in low revs ?

thank you
Amit
 
Re: 1.1 engine lack off power

If the breather blows a lot of air - it is blowby, or compression which gets by the piston rings into the oil pan. I would say at least some piston rings are blown or badly worn if there is so much blowby. Try to check water for oil contamination too, as it could also be a failed head gasket. A few possible problems, but I fear that not one of them is going to be easily solved without opening the engine.
 
Re: 1.1 engine lack off power

thank you for you answer
that what i thought . the engine did a lot of miles . so i have checked compression and it seem fine (195 psi) . can it be that i loose compression in to the oil pen and still have good compression ?
i do not have any oil in the water .

thank you
Amit
 
Re: 1.1 engine lack off power

That's what I was about to say - a wet compression test with oil. It might reveal more. But take in consideration - if there is pressure in the oil pan, it has to come from somewhere, and it has nowhere else to come from but the piston rings. There were faults known where piston rings break and fail, yet the compression test is generally ok. Maybe parts of the ring expand under heat and pressure - and there you have blowby.
 
Re: 1.1 engine lack off power

HI
thank you all for the replay .
did put some oil in one cylinder just to see if the compression is higher .
it was 220 psi . as to 195 before the oil. will try to check in all the cylinders.
will up date soon .

Amit
 
Re: 1.1 engine lack off power

Hi
there should be no difference when i check before the oil and after ?
i believe that even a new engine will give different compression with or without oil entered in to the cylinder .

thank you
Amit
 
Re: 1.1 engine lack off power

The difference should be minimal if the rings are sealing in the bores. If the oil is doing extra sealing then you will get this larger difference.

If there is no difference when the oil is added, it doesn't mean that the engine is OK, there could still be leakage past a badly seated valve.

Cheers

D
 
Re: 1.1 engine lack off power

Yep, only a leaking valve would not cause this much blowby into the oil pan. So essentially - if there is a big difference between oil and dry test, rings are done and need replacing. So I think you have your answer here.
 
Re: 1.1 engine lack off power

does 25 psi between dry and oiled piston is a big difference ?
what is the nominal psi for piston ? (i have checked autodata with no luck )
can a leaking valve cause lack of power in low revs ?

thank you all
Amit
 
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Re: 1.1 engine lack off power

Yes 25 PSi is a big difference, and it proves that the ring to bore clearance is too much.

Ignore the valve thing, that was for other people who don't get a difference when they do do a wet/dry test.

Its not only the total figure that counts, its how quickly it gets there too.

You have a problem with the bottom end of your engine, end of story.

Your lack of power is because for every explosion part of it is not pushing the piston down it is pressurising the crankcase.

Cheers

D
 
When i changed to a 38mm TB the car would idle much lower
i sorted this by adjusting the throttle stop screw which might
not have actually fixed it properly, then i fitted 75cam and
it started again.
 
Sorry to hi-jack a thread here but its along the same lines...

Cinq spec: 1.1, 38mm TB, 6 speed from earlier punto (lower ratio), gsr induction, custom exhaust, all fitted by previous owner.
Problem: Rough idling when first turning over engine, may cut out without revs, but no problem after running. Theres a real lack of power compared to my previous untouched cinq and real no power around 4-5k+. At 5k, it will sometimes 'stick', won't rev about 5k and other times it will go past, maybe with some hesitation.

Straight up, I'm a complete n00b.
I did take it to a garage and they re-attached some pipe (? - sorry I know thats no help and also sorted the speedo as the cable wasnt attached properly) but they didnt really solve the problem, can't really afford to just throw money at trying to sort it out, so my question really, is whats the best way of diagonising the problem.

I've done a quick look around tinernet, found a couple of sites ecu diag compression test . Is it best to just jump in and try and do a compression test (even for a complete novice) or take it down to a garage and get them to do a ecu diag (would that show it up on a cinq?) or ask them to do the compression test? I know an ecu diag is around £40ish, but what about a compression test. But, hey, if thats the same amount, can I buy the tools to do it myself? Alright I'll look now at compression tool costs but just general ideas of what it might be or the next steps would be really helpful.
 
Cost of compression tool link

Socket set to remove all sparks, in this goes, turn over by hand... record results? How easily can I screw this up? Actually why haven't checked the haynes

lol sorry for my rambles and I'm wasting peoples time :D

ok, checked the Haynes, gonna look into doing a compression test soon :)

Stay posted ;)
 
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my sei's dismantled and we've found worn piston rings too. was combusting loads of oil thus wasting lots of it and in turn reducing output!
 
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