Re: Diagnostic Testing?

Further update: Fitted brand new leads and coil packs, only drove it a short while afterwards and could still feel the flat spot.

Will reset the ECU properly as per Haynes and try again.

I am thinking Diagnostic and Pressure test now though.

Liam

Re: Diagnostic Testing?

Still not go the pressure test or diagnostic done but thought I'd try one more time with the symptoms just incase someone has had a similar fault.

OK - Poor performance between idle and 3Krpm in every gear, past 3K it's fine.

No loss of water, no water in headgasket, no mayo only visual inspection though.

Remedies tried

s/h but newish map - still the same

s/h lambda - still the same

Brand new coils and leads - still the same

Usual petrol consumption, no smoke from exhaust.

Totally confused and annoyed.

Cheers

Liam

Hi Liam
Sounds like it might be a fueling problem,mine has the same i put in a shot of redex and it runs fine and then another tank of fuel later and it`s back again,i`m thinking of having my injector cleaned profesionally,i`ve got a spare injector so i might fit that first and see if it helps
Try a shot of redex and see what happens
Cheers
Adrian

Thanks for that Ade, erm would a spare TB be a good idea? Got one sitting in the garage.

Liam

just try the injector, not the whole thing first

Looking at my pics now, it seems I only have the body part which could be bored out and not the top of the TB, I am assuming that the injector is the orange thing withwires going in?

Liam

Yes that is your injector, its either orange or yellow on the Cinqs that I have seen.

The only way to properly clean an injector is to get it cleaned sonically.

Aaron

Oh and you only need the body part of the TB if you are getting it bored out as the top bit stays the same.

yeah. i should have a spare this time next week if u wanna test it still then.

i cant remeber now which bit the throttle posistion sensor is in now either - could be down to that?

have u tried cleaning up the connections to the ECU from the wiring harness?

The connections are fine, erm, suppose a wee shot of carb cleaner and redex couldn't go amiss.

Keep the suggestions and advice coming guys.

Cheers

Liam

my sei has started to have this problem recently after fitting new coils / leads and starter motor... when i get to about 3k it feels like im being almost pulled back, loads of hesitation.... any ideas what it could be on a sei?

hi do you get the flatspots before 3k? how long does the flat spots last ?
my advise is to try changing the plugs first. how long have you had the plugs for? try NGK BKR7EVX they are in my view the best plug for the fire engine and does make the engine rev very freely. they are plat tips and are recommened by fiat motorsports.

as for head gasket and lamba sensors i really do not think that is the cause. also most cinq do seem to have a flatspot anyway towards the 2-3k rev range and its very difficut to totally get rid off.

by changing the plugs and leads and maybe a good service on the engine will make the flatspot better but i do not think it will totally get rid off it.

Being a Cinq owner for over three years I am well aware of the built in flat spot kindly provided by Fiat but this is hugely noticeable, up till 3K it is almost like someone is pressing dual controls in the passenger sie.

The plugs I have are the Iridium ones and were fine from April.

I changed the leads and it made no difference.

Liam

yes you said you have Iridium plugs, i would recommend them more for racing on the track more than road use becaused i did have a set myself and since i changed them i have noticed the difference. im sure the plugs are causing the flatspot more.

if you get the set that i recommended and did not like them, i will buy them off you.! thats how much i think they are that good.

Well thanks for your kind offer micro, the plan of action this week is a pressure test on the HG to see what this says. If it is clear i.e. allgood on each cylinder I may change the plugs however I fail to see how these could be at fault as they have worked for 3 months fine before. I may still have the old set of Super 4's I bought kicking around so may try them out.

Thanks for everyones suggestions and help on this.

Liam

i have a spare ECU, it failed wildly on emissions but didnt have flat spots from what i remeber. if you wanna try that out, gimme a shout and il get it in the post for you mate.

you'd need to swap ur chip into though, as its still coded

I was away getting a drink there (cola!) and while thinking of it, these symptoms are exactly the same as when I tried the Super 4's!

I might try and source cheap plugs tomorrow and try them, if they cure it I'll be one happy bunny.

Thanks Arc, I may still take you up on that.

Liam

Could only source some basic Champion OE spec plugs today but on fitting them it appears to be running better, will confirm after a drive tomorrow since it was starting from hot tonight.

Seems Micro was right, I dunno what it is with these plugs, I spend more money and get shyte. One of my mates tonight suggested decreasing the gap on the iridiums and trying again but I'll leave them be for the time being.

Liam

hi bloom hope all is ok on the plugs pls let me know if any improvements are made.

Well, I'd definately say it is cured, was fine today all below 3Krpm.

I am now happy again, Cinq is running well and will get a little run tomorrow night.

Thanks Micro!

Liam