pin point my problem on the 2.7

[Vagos]

The engine works overall good but it has one major problem!!!on low throttle it doesnt get any fuel in the cylinder.Let me get this from the start to skip confusion.My ignition set up is MSD6AL and MSD blaster coil with taylor wires.And im using an AFM guage with lamda sensor so i can see what the poroblem is.on the idle evything is good as i start to get the car rolling on the road very slowly and change from 1st to 2nd gear and i just slitly put the throttle i mean hardly touch it the the engine dies because no fuel is going in the cylinder.you can see the gauge going ---red and then 17 16af/r as as i keep progresive to push the pedal to a point i doubt that the pump jets come into play it starts to go to correct numbers will good fuel.On an uphill type of road it is even worse unless i hit the pedal to activate the pump jets it is dying due to no fuel.The 55s came with 60F8 idle jets due to the fact they have 3 progresion holes.I tryed first to drop down the gas in the idle by putting 55F8 and get a good reading of 12,8-13.2 af/r.problem was still there went up to 60F8 about the same arf/r just a bit richer still the same.Went finaly to 65F8 got a reading of very rich mixture of 10.5-11.9af/r on idle but no cure to starvation on rolling with almost closed batterfly.Now either the progresion holes are not big enough for almost 700cc in each cylinder which i have or the accelarator pump rod is too sort for my engine also.But those 55s were suposed to be made for big engines.On full throttle i have no such problems.Change also the pump jets from 45 to 55 still no cure,will try to change the pump spill valve from 100 that it is to 50 to zero to see if it will make any difreence.but i doubt that will be the cause.I am also starting to thing the MSD might be playing tricks one me.I had this combo of spark ignition on the manta a motor.On 2nd gear and uphill it did do me such things.When i put my MSD ignition combo on the 2.7 car at first didnt run well at all and found out that it was the blaster coil!!the MSD coil was new and working untill the day the motor of manta a destroyed the 4th piston.Replace the coil with a new one and it work perfect.MSD suggest without the MSD6A and installation of ballast resistor but with the 6A that is no nessecary.I did get this MSD6A used and not new.Today as i had the car on the idle it started working like crap.turn off the engine put new plugs in it turn it on and still run like crap.pull the plugs and fount that the 1st and 2nd cylinder wasnt working ony the 3rd and 4h.Probably another coil fault but why???Lot of thinks to consider and think.By the way with i have two Red top facet installed in the trank each from its own source drowing fuel and then connected with a T piece pipe and with a fuel presure regulator dropping the presure to 3.5psi before it goes to the carbs.So fuel pump not be able to cover me up is probably out of the question.Can anyone drop some light in to this????

[Hiro]

Sorry Vagos here I can't help you with these big DCOE,
To avoid this kind of mess I turned to the Megasquirt EFI,
It's very cheap & easy to tune with your wideband EGO probe.
Becarefull when running too lean even with your forged pistons,
Would be a pity to harm your 2.7 stroker now!
Hiro

[Vagos]

Im gonna check the progresion holes on a pair of 48s tommorow that i know that they used to work ok on a 2.7sroker also.I have a stock one 48 to compare with it.With one look i gave it to it the progession holes was a bit deeper.will see tomorow.Maybe the 55s holes need also enlargemend to allow more fuel.Yes iam afraid also running to lean thats why i want it sorted out as soon as possible.thankfully is happening very fast.

[wrench459]

Vagos your right to question the MSD box! Make @##$^ sure that large black wire goes to a good ground. Better yet straight to the negative post of the battery.
Those boxes are very touchy when it comes to grounds.

If the motor misfires(ignition) the wide band will show a lean condition because of the unburnt oxygen in the exhaust.
One way to tell the difference between ignition and fuel issues is to look at the exhaust numbers.
If the problem is on the ignition side the HC numbers will be very high around 1500 ppm's or more.
If its fuel the HC numbers well be very low under 500 ppm's.
Then theres the CO and NOX that also needs to be added into the mix..

Hope my dribble helps somehow.

[Vagos]

NO luck tried to work the car without the MSD6A.Same crap just run lean on progresive accelaration.Even stoped on Idle with neutral when you have a reading of 12-13.5 AF/R when you hit the throttle it goes to lean.Put the car in an exhuast analyzer as wrench recomended.And Found out that ppm was high about 1150-1230 and co reading was 3,8 and co2 was about 7,9.So probably i would be looking at the ignition.What might be wrong the bosch sensor under the coil or the distibutor itself.more tests tommorow.But i dont see any light at the end of the tunnel and all this state is realy starting to bring me down

[Vagos]

offcourse high ppm numbers may also ocour from the long duration of the camshaft i wear.342@ unless even with such high duration camshaft you cant even go so high unless you have faulty ignition.Can anyone drop some light here?

[wrench459]

Vagos
The CO of 3.8% and HC of 1200 ppm sounds about right.
Depending on the length of the exhaust pipe and the sample tube from the analyzer. There can be a long lag time to get the correct numbers.
My guess would be that you missed the drop in CO and HC's and the rise in NOX.
This is sounding more like the classic big carb. big cam fuel transitions issues.