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Zetec & Weber 40 DCOE Issues
ttalps2000 - 28/11/17 at 08:37 AM

Was trying to set the emmissions last night on the 1800 zetec, which has 40 DCOE webers on it.

I can get the CO down to around 3%, but the HC's are up around 2200ppm, which I need to be down at a max of 1200ppm for IVA!

From memory I have 45f9 idle jets in the carbs, anyone else running this setup on a Zetec, if so, what idle jet sizes are you running? Raceline have recommended running 50f9, but thinking I may need to go to f8 or even f7 to lean it off more.

However, I'm not sure what the 50, 45 side of things relates too. the f part gets richer as you go up the numbers, but I need to back-off the air side of it and not the fuel.

There was so much oxygen in the gases that the meter didn't pickup the probe was in the exhaust until we revved it up for a while!!

Thanks


cliftyhanger - 28/11/17 at 09:13 AM

High HC can be down to balance.
As an aside, is the engine early enough not to require a Cat??


ttalps2000 - 28/11/17 at 09:30 AM

Its Feb 1992, so no cat needed, but still have to have 3.5% CO and 1200PPM HC's or less

Will check the balance on the carbs as I didn't and should have!!


perksy - 28/11/17 at 08:57 PM

Google Dave Andrew's Weber jetting program online that's usually pretty good, He also has some very good info on setting Webers up


ttalps2000 - 28/11/17 at 09:21 PM

i have the program, but get completely different results to what Raceline gave me, on the Toyota it was bang on though!

Rolling road now booked for 13th Dec, so will get it sorted!


ttalps2000 - 7/12/17 at 09:05 AM

Figured out what was going on with the carbs last night.

There is an adjustment screw that links the 2 carbs together on the linkage, this was holding one of the carbs open and not allowing it to fully shut off, hence the high idle etc. As soon as I removed the screw, could balance the carbs correctly and re-adjust it all again. Runs perfectly now.

Still going on the rollers though!