HELP - RUNNING WEAK ON 1 & 2!!

[timbo]

 

exhaust primaries 1 & 2 glowing red!! No. 2 starts to glow red 1st then no. 1.

plug reading on 1 & 2 - v. lean (2 'whitish' marks on exhaust valve side of plug)

Start to get exhaust valve burning smell after running. (no. holes in piston!!)

plugs 3 & 4 - v. sooted (4 runs lambda)

Lambda reading - 3 bars into rich which would be right re. plug 4 condition.

 

Setup:

 

std 1.6 K running std cams

long 4 - 1 competition exhaust (no cat)

VHPD TB's on twin induction manifold

M3DK - using spall.fig map.

IACV - running mapped idle - IACV closing at load site 2

wasted spark.

twin coil running 1 & 4 ; 2 & 3.

using VHPD injectors

timing never adjusted from std engine setup.

Running fuel cut off at load site 0 above 2000rpm.

 

 

Suspect air leak on manifold firing 1 & 2.

just Fitted VVC inlet manifold gasket - (originally used bead of hylomar - this disintegrated in no time - and I thought this would have solved my problem) - NO!! glows after about 5 mins

 

Suspected VHPD TB's to large for std 1.6K setup? - Don't think this is the problem as cylinders 3 & 4 would show similar mixture problem.

 

Have richened injection mixture throught injection map - no better.

The ignition map runs 0 advance at 1000/1500 rpm?

 

Any ideas guys? I am stuck - the car aint driving a mile until I get this sorted.

(TEL) 02838 333344 to 1.00pm.

or MOB 07801 364976 - ps. my mobile is bust - I can't here you but you will here me. I'll return your call on the logged number. I ran over the damn thing the other day.

 

[Johnty Lyons]

Tim still think your running too weak on 1 and 2 has to be an induction problem on that TB shes drawing air theres no other explanation.

 

jj

N.I. L7C AO.

Membership No.3927.

[Johnty Lyons]

Tim do a compression test as well and ring me on land line.

 

jj

N.I. L7C AO.

Membership No.3927.

[timbo]

Sorry to phone you so early this morning.

 

I have ramped up timing at load site 0 1000/1500 rpm from 0 advance to 8 advance.

 

Plus increased jetting right across map - set from idle trim +3 at load site 0 c. 1250 rpm. Spall map has richer top end but weaker middle so I have added a v small increase to the mixture ratio in the lower/middle sites.

( I am running 45s (Spall 42s) so a little bit richer will do no harm)

 

Set idle at mapped setting - IACV close at load site 0.

 

couple of things after trying this - she didn't glow - but I am still not sure its fixed as I ran the eng cautiously.

 

Cut the revs at load site 3/speed 6 c.3000 rpm. 1 & 2 still too white compared to 3 & 4.

 

Plug 1 had cracked white resistor cover!!!!

 

Changed all plugs as precaution & ran for 10 mins (97 temp). plugs came out as clean as put in??? no tanning whatsoever - all plugs same reading - but perhaps 1 & 2 slightly hotter to touch on te resistor than 3 & 4.

 

Checked timing marks - cams line up inlet-exhaust mark & bottom pulley to 1.00pm mark on timing cover.

 

Noted that when ran eng. exhaust cam pulley has a v. slight lateral wobble!! compared to inlet cam pulley. Can't see any wrong with hydraulic tappets on 1 & 2 or cam lobes to suggest problem.

 

I have stripped off trumpet cover. when observing the butterfly motion I have noted that the balance is every so slightly off on 1 & 2 - when closed on

4 & 3 I can screw out the balancer & 1 & 2 closes v. slightly - where talking max 1/2 mm. I am sure this contributes to the problem but it wasn't open enough to cause all the problem in my opinion.

 

I am at the point of taking the damn thing off - putting back on the plenum & enjoying whats left of the summer!! leaving it to the winter.

 

I want to get the 7 back on the road for the meeting & track evening - the plenum may be the safest route?

 

Are you free tomorrow??

 

 

 

 

 

[timbo]

SORTED - the v. small inbalance in between the tbs was the fault - she now idles sweet.

 

By removing the restrictors and soldering the butterfly holes the percentage airflow increase from closed to even slightly open is much greater. This meant that opening no matter how slight would be drawing in more air.

 

You were spot on Jonty re. induction leak.

 

One prob - when i cut the engine she runs on slightly - to much advance at idle?

 

Plud temp guage reading 80 - M3Dk reading 102 when fans cut in - looks like temp guage wrong. (thermostat opens at 102).

 

I'll catch on the mob to update.

[timbo]

Hold that thought - maybe not sorted!

 

Before taking a run I have tested the plug readings again.

 

4 - light tan

3 - sooted

2 - clean

1 - clean

 

Still not right - what are your thoughts Jonty?? I have got to get all 4 the same reading before I take this baby out.

 

The only place left for a leak can be the IACV - could it bleed air in varying amounts to individual cylinders - I would have though 2 & 3 would suffer most as valve is in centre. TBs air bleed offs via fuel reg tight - put cable ties at base to make sure + pipe plugged. VVC inlet gasket fitted - manifold torqued to 34Nm. Butterflies balanced. Compression 12.5-13.0 bar on all cylinders. Tbs to manifold tight (gasket between). Spark plugs tight. Idle perfect.

 

Ps. hope the evening run went ok.