Cold start/idle problems with my new ITB 182

[Grazzaz]

Hi,

I'm new on here and wondering if anyone with ITB/OMEX experience could share some knowledge on cold start problems I'm having.

I decided to sell my Evo 7 and drop 500kgs back to a Clio to do more trackdays and bought a stripped 182 which has been extensively modded with ITB's at GDI - which I have now learnt have merged with Ktec.

I'm still trying to work out what camshafts are fitted but it has (receipts for) Jenvey ITB's, Omex ecu, angelworks flowed head, lightened flywheel, Racelogic traction control, decatted performance exhaust, oil cooler etc.

I'm guessing it has got high lift cams as there is a rolling road printout with it from 1320 autos cambridge for 234 BHP / 182 lbft - now I used to have a stripped out 172 cup about 5yrs ago and this new one is a quicker car but I think these figures are a bit optimistic! lol.

Anyway, it drives well and the power is quite good (even compared to the Evo just totally different delivery) but the idle is quite high and a bit lumpy (1100 rpm warm - any lower it gets rough) it pulls reasonably well from the bottom end, not mega brutal tho - I guess this is a consequence of ITB's though more revvy than torquey? - do other people find this? I think having jumped out of a turbo'd car I've been spoilt a bit with all the torque in the middle of the revs. How do other peoples ITB clios drive?

**the main problem**
Aside from the high idle when warm it is a real pig when cold. Very rough idle and for the first 5mins after cold start it is very low on power, slight misfiring. It can stall easily at this time while idling. The coolant temp gauge stays at zero for about 5-10mins driving then very quickly (30secs) shoots up to the correct temp and it drives much stronger then with a smoother idle albeit a bit high I think.

I am away this week and thinking how to tackle it when I get home - I've read the big thread by Nick B which looks to be caused by incorrect cam timing, I don't think this is the case with mine tho as I still have quite good power etc when warm, and there is still a vague vvt kick at 5k rpm so I guess thats still operating.

I don't expect it to be uber smooth being highly strung in the first place but I'm thinking it may be overfuelling possibly due to a sticking thermostat (is this common to stick open) or a dodgy coolant temp sensor? How do others run?

I've never used ITB's before but how do you allow for cold start enrichment? ie. with no idle valve or flyby wire throttle how can it ever let more air in with the extra fuel when cold - do I just need to hold the revs up on the throttle for a while until it will drive without misfiring? as i say it is only rough like this for 5 mins then it is great - no misfires at all.

I'm thinking the coolant temp is my biggest area for concern as I reckon its chucking loads of fuel in on startup and theres not enough air to burn it so its lumpy as hell until it leans off. Could it be the mapping tho? I've downloaded the Omex 3000 map software and have a lead coming to have a look at whats happening in the ecu.

- maybe someone knows it....KR04ZHC????? It was owned by someone near Miltonkeynes then someone in Plymouth who did most of the work.

Any advice would be really appreciated - sorry its turned into a long post, thanks for reading!!!

Cheers
Graham

Ps. If anyone is selling a bolt in cage I would be interested

 

[Fred@BTM]

where you based? sounds like it needs looking at

is it a blue 182, i think i know the car

 

[sideways danny]

I think we advised this as having a broken TPS about a year ago. The jenvey TPS is notoriosly not very durable, and once they start to cause electical noise you get accelleration fuelling when you're just idling, hence running rich

 

[T.Trophy]

Mate you've hit the nail on the head with your diagnosis, it's the lack of idle valve thats causing the issues and is something experienced by a number of people moving from a drive by wire throttlebody to a cable operated body (single or multiples).

Best person to speak to would be Andy Cutler at KTEC as he'll of been the person responsible for the car.

 

[Grazzaz]

Hi Fred,

Yes it is! do you know any more history on it? It seems great other than this .
I'm in Warrington jnc 22 M6.
Do you have any ideas what it could be?

Cheers
Graham

 

[geesus69]

Hi Graham

my ITB'd 172 engine is exactly the same, when cold i have to rev it for a min or so to stop it stalling, then when it gets slightly warm it's fine

i think cold start is always a bit of an issue with ITB's

and don't quote me on this but i think i remember hearing that if you sacrifice the cold start it can perform better elsewhere, getting a perfect cold start can mean less performance (albeit very slightly)

mine is track only and gets trailered everywhere now so i just live with the cold start issue, sort of reminds of race cars that need pushing out of the pit garage and onto the grid as they are such a pain to drive normally lol

 

[mwn11]

If there not on the receipt i would guess they are standard cams?
Although 234 sounds high. Rollers could be out.

The starting should be a mapping problem.
It should have a custom map from GDI/Ktec

If you have installed new software this could of messed the map up.
Or if the guy before has tried to install a new map.

Or listen to all these experts haha

 

[sideways danny]

It'll be either a faulty TPS or coolant temp sensor

 

[Grazzaz]

Thanks for the info Danny, it drives great the rest of the time so I guess this may have been replaced. Was it the same complaint?

Ok Steve I will try and contact him and see what advice he has, thanks.

Cheers
Graham

 

[Tom84]

my just be the type of bodies used as some dont have the idle air bleed, i know some of the jenvey tappered bodies dont and they rely on a small throttle opening to maintain the idle, unlike the parallel bodies that have a bleed

may need the bodies balancing for the rough idle as it should be quite smooth

 

[Grazzaz]

Just dug some more receipts out and I have rolling road results as follows;

02/08 Engine Tuner Ltd Plymouth - Dynodynamics road
1 run at 155 bhp ? maybe a fault or before some mods?
1 run at 186.9 bhp (it already had the flowed head and other bits at this stage by the look of it)

07/08
ITB's fitted and mapped at GDI

07/08
1320 Autos Cambridge - never heard of these?
234.4 bhp / 182 lbft

I've not touched the map yet - when I get the lead I was just going to have a look and see if i could read any live data out like coolant temp sensor TPS etc.

 

[Grazzaz]

If its the throttles which require balancing is this something I can read up on and do myself? - can't find much info on this
If not is there anyone in the northwest area who can be recommended?

Maybe even get it back on the rollers too and check the output properly and make sure the air/fuel ratio is right

 

[sideways danny]

Where are you in the country?

 

[Grazzaz]

Where are you in the country?

Warrington, jnc 22 m6

 

[sideways danny]

Bit far from me to have a look for you

 

[Grazzaz]

Hi Geesus! Yeah I always knew an entirely track focused car would be more of a pain to drive and it's reassuring yours is the same. This is my daily driver at the moment until I can sort a run around out so just trying to iron out the huge lack of power and mis-ing in the first few mins/miles. I've found myself driving further out of the way once its warmed up just to enjoy it - a little run to the shop is now a D-tour!! lol

Hi Graham

my ITB'd 172 engine is exactly the same, when cold i have to rev it for a min or so to stop it stalling, then when it gets slightly warm it's fine

i think cold start is always a bit of an issue with ITB's

and don't quote me on this but i think i remember hearing that if you sacrifice the cold start it can perform better elsewhere, getting a perfect cold start can mean less performance (albeit very slightly)

mine is track only and gets trailered everywhere now so i just live with the cold start issue, sort of reminds of race cars that need pushing out of the pit garage and onto the grid as they are such a pain to drive normally lol

 

[Grazzaz]

No probs, thanks anyway. I am prob going to get it dyno'd again to check the AFR as I don't have a probe yet. Depending on what turns out from that replace the TPS and/or c.temp sensor and take it from there.

Bit far from me to have a look for you

 

[Grazzaz]

Hi,
What rpm would you expect it to idle smoothly at? I've read on here some people are down at 8-900 rpm with their tb's! I'm used to a high idle on the evo about 950-1000(1500 cold), but a lumpy 1100rpm is a bit anti-social first think i the moring (when i have to blip it to keep it going) with a straight thru exh.lol

may need the bodies balancing for the rough idle as it should be quite smooth[/quote TOM84]

 

[sideways danny]

better to plug in a laptop, do some data logging and see what's happening.

Think target idle would be bang on 1k. Can be seen in the software, the ECU adjusts ignition timing to raise or lower rpm at idle

 

[Tom84]

from the road cars that ive set and heard running the idle should be smooth, only time it wasnt was when the balance was out, but could also be another problem.

if you take it to get dyno'd they should have a syncrometer to check it will be a quick check and atleast you will know they are right. if you was closer i would glady check them for you but ur miles away

 

[Grazzaz]

Thanks for all the advice guys - a really helpful forum!

 

[Grazzaz]

Thanks to Andy @ Ktec for finding all the history for me, mega helpful guy! nice one