Not Running to healthy

[cliffb75]

I've had another thought

The reason this all came about is because you re-built the engine right? With a somewhat more wild cam in it?

Have you actually tried changing anything in the calibration to cope with this? The missing at idle could just be due to the increased overlap, and you may need to run richer, and/or a higher idle to compensate, and maybe even advance the idle ignition (rotate the dizzy a bit.

I've not seen the map trace, but again if you're getting a lot of reversion/pulsations the MAP sensor won't like it. This is precisely why alpha-n was developed.

We are all assuming there is some problem here, but it could just be your 'improved cam'

Just a thought.

Since it does just about idle it might be worth trying to take it for a drive, though I guess you will need to re-map the fuel for alpha-n as you go, or let it run closed loop.

Also, try putting the target lambda to no leaner than 0.95 for now, as this will give you a bit of headroom on the lambda front.

What do you think?

[Tony C]

the car has been running sweet with this cam mate,
i have covered 40 miles trouble free like i said in a previous post,
but the following day this started to happen,
why would the car run sweet one day after rebuilt then not the next???
this is whats got me thinking,

[dnb]

Tony - would an extra pair of hands on site help?  If you can find a way to get me to Newbury or you & the car to Southampton I'm happy to spend Sunday tinkering with a different v8.  I'll bring up my spare VEMS etc.  (I doubt I'll get a car on a sensible ferry at a sensible price at this short notice, so I'll have to be a foot passenger)

[Tony C]

thanks for the offer Dave, BUT this sunday is a no go im afraid,
i spent all easter on the car and the mrs hit the roof,
I have had strict orders not to even talk about the car let alone work on it on my daughters birthday on sunday

[dnb]

I know exactly what you mean...  The offer's still open for some other time.

[Jorgen]

Hi,

It's sad to see the trouble you have with the engine. I have found that the launch and ALS settings are not disabled properly. Without the switch and pullup installed these can flicker on and off which will make the engine sound pretty sick.

If you look at extras-> Advanced ALS you see "Input channel used:", this should be set to DISABLED.
Then check Extras-> Launch control. Make sure that "Input channel used:" is set to DISABLED.

As you have trouble with the engine I suggest that you disable the closed loop control until the engine runs well again. It can make matters worse.

I heard that there was very high intake pressure at some time. I would need a log of the engine with the MAP sensor connected and used, the MAP must always have it's own connection to the plenum. It's our primary load sensor and we don't want bad load readings if an other component breaks.

You mentioned an engine overhaul, was there headwork involved? New lifters? Pushrods? Rockers?

Do you have a boost or vacuum gauge that you can read while the engine is idling?

Jörgen Karlsson
Gothenburg, Sweden

[Tony C]

Hi Jorgen,
yup new cam (crower 50233) crane hi rev lifters and stg3 heads,

what no one has been able to expalin is why the car ran sweet for 40 miles on the day of fire up.
then do this the day after, surley if the engine mods are the fault would it not of played up from day one of start up?

[Tony C]

i will see if i can get a vacuum or boost gauge

[rob@vems.co.uk]

Just switch it back from AlphaN to Speed Density (change Extras->Alpha-N / Speed-Density Blending min and max RPM back to Zero)

And crank the engine over (your VE Table will be wrong now so you may not get it to start might be an idea to upload your old VE Table).
That will give you a manifold pressure reading datalog the same as a guage will give you.

There are so many potential factors as to why the car ran well then went to pot that we're just trying to establish what they could all be, and once we've got them all lined up we can pick them off one at a time.

Rob

[Tony C]

cheers rob

[Tony C]

will upload a datalog of us playing and one of the car on its own, have had to hold her on the throttle a bit to idle and also no matter how much we set the idle control valve it never idled above 1100 even with the valve wide open,
we did notice the temp scale was reading 102 in MT when the gauge on the car was only at half way,

[Tony C]

try this guys,
http://www.v-8.org.uk/ecu/28-04-07.zip

im going to drop the mallory ignition amp out in the week to eliminate that from the equasion, as i have just rebuilt the dizzy today with new electronic eye and rotor arm so i know thats all good,

[dnb]

we did notice the temp scale was reading 102 in MT when the gauge on the car was only at half way,

This is a little worrying.  Mine did this every so often, and I put it down to a dodgy sensor earth since there was no way it could be the real temperature.

[Tony C]

at least its not just me then, what would cause this mate??? as is a little worring as would the ecu not try and change the fuelling for the high temp?

On another note may be making a bit of progress,
had the car running on the o/e map etc had to open the idle valve a bit more but had it idling,
it looks like my passenger may of damaged the wiring loom, as if you wriggle the ignition trigger wire the revs pick up and down
so off back round to run another wire (not a shielded one though as not got any) just to see if this cures it,
will report back soon,

[rob@vems.co.uk]

Damn, thats as noisey as hell.

Lets think about grounds.

I'm wondering about finding a way of disconnecting everything and just looking at the ground noise...

I have visitors now so I have to tend to them.

Rob