Misfire when on boost

[Colza]

My engine started doing this today. This morning i started playing with boost levels using a bleed type boost controller. At one point a hose came off and i managed to get a boost spike up to 1.5bar before the factory 1bar boost cut stopped it, this may have something to do with it but the misfiring didnt start till later in the day.

It is not a regular fault, sometimes i can boost ok up to 1bar, other times barely get past 0.1bar before it is missing so badly it wont go any further.

I have cleaned all my plugs, changed coils, cleaned the dizzy cap, and removed the boost controller.

There are no error codes showing on the ECU so it seems it is not a wiring/sensor problem.

After checking the last of the things mentioned i went for a drive. Everything seemed fine, boosted perfectly. I drove for about 5 minutes with no problem at all, but just as i came back to my house it started missing like crazy and would not even drive at anything above 0 manifold pressure  

This has me stumped, its nothing i have ever come accross before. I dont have any of my beloved error codes to work from either ??? It might very well be something to do with the new manifold, but it seems strange that it would run prefectly for 2 days then suddenly go wrong.

Stupid stupid STUPID car >:(

[Kam]

I got a problem like that.  When I get it (usually on the highway) I put the clutch in, turn the ignition off then back on, then release the clutch.  All this at around 100kph!  

I think its got to do with a dodgy wire to the map sensor but haven't got around to fixing it.

Tell us how you go and good luck!

[JohnT]

Any chance you've destroyed the turbo / made it intermittently not run? If you have, you wouldn't get above 0 (atmospheric pressure)

Pressure surge like 1.5 Bar could damage bearing in turbo.....

John

[Colza]

LOL, nah its definately not that. On occasion it does boost perfectly, and when it is running like shit i can pull massive backfires and flames out the back that i can see in my rear vision mirror That sound like a dogey turbo?

[QikLude]

that so sounds like a timing issue eh...

Cheers

Jw

[city_cabriolet]

Put the old manafold back on and see what happens?

[tegracer]

we had a similar problem when we hit fuel cut while setting the fdc.
jumped one tooth on the cam gear

check the cam timming..................

[Colza]

It doesnt feel like the times when ive run it a tooth out before, too good off boost, but im going through all the timing things at the moment. Recon distributor coming tomorrow so well see if that helps.

Does the distributor have flyweights in it? Or is there nothing but the vac advance to do timing corrections...

EDIT:
Well according to this post yes it does

[quote author=JohnT link=board=ForSale;num=1085121506;start=0#1 date=06/03/04 at 15:05:35]Civic_killer

I have a distributor spare if you still need one. Henry recently borrowed it to check out some issues with his City and sent me an email saying:

John, your distributor has been tested. It's had a bit of a hard life, the centrifugal advance mechanism operates but could do with a clean out (dry grease) the vacuum section was quite gritty, cleaned it out and re-greased but still not smooth. Vac advance canister is shot, centre (coil) contact broken in the cap but have replaced that, fitted my vac canister and it is now on test and performing same as mine, so it's now a useable item. I guess the only bit that could pack up in there is the igniter but that is ok. Will fit T1 or T11. Will put a note with it when I bring it back.

So if you still need. let me know. In this condition we're talking $50 plus freight - which will be around $20.

John[/quote]

[doggystyle]

if your pulling flames and b/fires then your not burning fuel proppa and filling yo exhaust with it.... sounds like ignition or fuel.... are you foulings plugs?


EDIT: yeah the dizz does have centrifical weights.. but i cant see how they would suddenly pack up... though it cant hurt to check them and make sure their free

[Colza]

As its misfiring and not burning in the cylinders i was assuming all the fuel/air was just getting pumped into the exhaust, where presumably it is managing to ignite.

Or, the cam timing is out, and it is sparking while the exhaust valve is open :-/

[doggystyle]

are you fouling plugs tho?... what about your ignition timing?.. either that or your pumpin to much fuel

[John_S.]

Didn't you say you still need to get the CVCC worked out? Could be you are running waaay too lean which can cause you to burn a valve, which can cause you to be spitting out the exhaust...happened to me on a USA CVCC EM1 where the CVCC fuel port in the carb was gunked up and not supplying enough fuel to the CVCC valve assem. And it happened FAST too, almost no warning. Try running a compression test to be sure all cyl are still tight. Cross your fingers...

[Colza]

John: HOPEFULLY NOT

Well i put in a recon dizzy today. Idles smoother, runs smoother off boost. AND it now boosts up to 0.5bar!

So hopefully i just proved it is a spark problem. But havin said that, its not fixed yet...