Lumpy Blackbird

[Krismuss]

 

No jokes about Chaka Khan please......... 😳

 

Took BBird out for MOT today and gave her a good 'airing' down the Caterham bypass (A22), though on low revs the car sounds as sick as a dog and pops and bangs like billy-oh! (though does clear with a good revving).

 

Car's due for a service with Andy Belcher shortly, where should I start looking to cure the lumpy low revs? I was contemplating a trip to PDQ for a rolling road and DynoJet check up.

 

As an aside, what's the likely cost of a rolling rod session & tune/mapping?

 

Chris

 

 

Orange and Loud

 

 

[Stationary M25 Traveller]

Have you started by looking at the state (colour/gap) and tightness of the plugs ?

 

 

[blade_runner]

Leaking Exhaust?

 

'Pinky Pics' here

[Krismuss]

Was worried about the zorst, has got worse over last few weeks.

 

Started only when car was warm, now it's from cold too.

 

Best start looking this weekend

[Neil Felstead]

I would let Andy look it over before spending hard earned dosh on rollers etc. It may be a service item at fault, plug 🤔

 

cheers

[Howard R]

If it was running fine before and if the Bird's been laid up all winter it could be varnish on the jets from the fuel (assuming its not an injected Bird )

 

 

Green Fireblade Pilot

[neilg]

Chris, sounds like a leaky exhaust. Does it do it on the overun or on steady throttle. Overun sounds like zorst , steady state throttle maybe on the inlet side. Check all those ht leads , plugs, coils etc. Are you on carbs or injection , can't remember??

Rolling road about £60-00-£80-00 per hour.

Cheers Neil

 

[Stationary M25 Traveller]

It was probably over-excited, seeing all those other BECs at Botley Hill !!!!

 

 

[Bitsilly2]

PDQ charged me about £65 per hour but then rounded it up to 3 hours. If it is on carbs then they would probably benefit from being balanced.

[Krismuss]

Thanks all!

 

Neil, it's generally on overrun though last one was on startup at low tickover (hadn't even got in car) when it just banged & cut-out. It's an injection with a dynojet commander.

 

Was going to check plugs & leads as it felt very similar to when SWMBO had an old golf that mis-behaved in a similar way which proved to be new leads.

 

SM25T - plenty of BECs at botley there's also a BEC meet at Bletchingley (another good reason to move there if it ever goes through - anyone want to buy a house in Caterham )

 

Chris

[Mike Molloy]

I have had a bout of rough running in the past and I'm sure it was down to low battery voltage. I did all sorts of compression and leak-down tests as I was sure I had burnt a valve or something!

Also check your fault codes and do a ECU reset if necessary.

[Krismuss]

Mike,

 

Voltage seems fine, though checking plugs they are all 'dry-black' (very sooty).

Have cleaned HT leads and checked air filter (reverie carbon intake with foam cone filter) which was filthy!!

 

Haven't started up again (kids asleep!!), how do I perform an ECU reset on a Power Commander (Dynojet) if I need to and does it lose any map on it doing a reset?

 

Meant to add, I don't have an interface lead to the Dynojet unit, should that be my 1st purchase?

 

Thanks

 

Chris

 

Edited by - Krismuss on 16 Mar 2009 21:31:58

[Mike Molloy]

Ummm, no idea about the Dynojet ECU. I bought one off E-Bay but have yet to try it. A previous owner of my car said he had one fitted but Caterham stripped it off when they re-sold the vehicle. Something to do with difficult starting? Not sure...

 

By "reset the ECU" I meant the Honda engine management unit. Details are in the Haynes manual or here.

You link two pins of the diagnostic connector and watch the FI warning light.

At one point I had racked up some faults and my engine was belching flames on the over-run. Cleared the faults and it seems to be running OK again now.

 

I'd definitely charge the battery up though. I am very suspicious that my rough running problems were because my Odyssey battery was donald ducked.

 

Edited by - Mike Molloy on 17 Mar 2009 13:47:54

[BYKer Will]

Kriss

 

If it twas me I would do what Mike said and make sure the battery is in good nick and well charged.

 

I would then give it a decent part service before handing it over to Andy to do the bits you cant or don't want to do .

 

If your air filter was filthy that might make it run rich and hence the black plugs and hence rough running(checking they are all the same might shed some light).

 

To start I would stick a new or clean filter and some new plugs in as the bike plugs have very fine tips and I dont think they clean up like they did on my mini.

 

Check all the obvious plug lead caps and low tension connectors on the coil pack and I assume you have nice new fuel not last summers like mine?

 

The dynajet 2 which I think you have just overides the map at various loads or revs in the standard honda ecu. If they fail I gather they just stop working altogether and you end up with the standard honda map which is probably not far out anyway.

 

If checking the basics doesn't fix it then I would recomend you try PDQ but make sure they have all the leads and software for your particular dynajet and ideally a spare or replacement one before you turn up and waste a day like I did somewhere else!

 

Personally doubt it is an air leak in the exhaust. Mine is always slightly blowing from one of those bar steward headers that you cant quite get a spanner on or from one or more of the primaries and still runs fine.

 

Best

 

Will (i'm just about back from my sicky but still haven't been in the bird since september )

 

PS What are these botley and bletchingly bec places of which you speak ?

[Stationary M25 Traveller]

Botley was a Pistonheads meet in the fog a couple of weeks ago ... lot of BEC arrived !

 

Glad to hear you are off the deathbed .... now get into that bird 😳

 

 

[Krismuss]

Hi Will! No blackbirding since September 😳

 

I'm carrying out basic maintenance (as suggested) prior to going to Andy's next Thrusday. Plugs have been changed (ouch - mucho bucks!!) and cleaned the air filter though a new K&N cotton filter is on its way from Reverie (more ouch!).

 

As an aside all the plugs were black so not an individual cylinder/valve problem.

 

I've cleaned all the leads (had a similar proble years ago on an old Golf [and a TR7 as I recall] which cured with new leads/dizzy, etc.). Car's only done 10k miles so couldn't be leads in that time, could it??

 

I spoke to Neil at PDQ re:DynoJet Power Commander & he suggested the PCII on ine isn't the best of devices and whilst he could work on it would recommend replacing with a PCIII if possible (last resort - just too much of a cost ouch!).

 

Botley Hill (Kent) was a Piston Heads 'supercar' meet a fortnight ago, some cracking cars there, see SM25T's pics here

 

Bletchingley (Surrey) is a BEC meet that one of the guys from the PH/Botley meet told me about that's just down the road from me (about 2 miles from caterham) that I might pop along to next month - I met a couple of guys with a R1 Indy and a Busa Westfield at the PH do.

 

Just stuck a set of R888s on mine, unbelievable difference to what was on there (even with the carp running), really sticks in round the corners though must get LSD sorted/seen to now.

 

Am aiming to get to a trach day some time soon (probably Brands if I find a 'friendly' one) though work's pretty grim at the moment so unnessential expenditure is being kept down where poss.

 

Blats are getting further afield now so perhaps I can venture north of the Tunnel one day 😬

 

Cheers

 

Chris

 

Orange and Loud

 

 

[Krismuss]

Update.......

 

Amazing the difference a new set of plugs & clean air filter have made

 

Yeeehaw 😬

 

Chris