My 427 SOHC Build..... Finally the time has come!

[cobracammer]

Also, pulled plug on cylinder #5 (chosen at random).  Wanted to see if its all blavk and fouled up from a rich idle mixture....  actually not bad.  Definately not black, but not white from running too lean either.  Right about in the middle ( tannish color ?) with a slight hint of the smell of fuel. 

[jayb]

Jason, thanks for the picture.  Since there is oil on top of the intake I would say that is a leak around the distributor, not between the intake and the block.  There is a round rubber seal that goes around the distributor and is supposed to seal to the hole that goes through the intake; maybe that seal went bad or something.

The triangular shaped hole towards the lower left on the picture actually will go all the way down past the head and out the bottom, past the left side of the timing cover.  Is that the "well" you are talking about?  Any oil there should drain out the bottom by the front cover.  Are you seeing an oil leak at the bottom of the engine, at the front?

One way to solve that leak is to find a couple of O-rings that fit around the distributor in the seal position, and put them on the distributor first, then re-install the round rubber seal.  That will space the seal out so that it seals against the hole in the intake. 

[cobracammer]

Hi Jay.  The "well" seems to be between the backing plate and the front of the intake manifold.  Pools in a little area right next to the distributor, but not on top of the intake( hard to describe).  When it fills up, it drips down the little opening between the backing plate and the drivers side head and pools on top of the oil filter adapter.  Doesnt do it at idle, so must do it when under acceleration only.  Seems to be 3 seperate leaks.  This one in the front, a really small leak at the dipstick tube, -and the mystery one that drips down the bellhousing.

[My427stang]

Also, pulled plug on cylinder #5 (chosen at random).  Wanted to see if its all blavk and fouled up from a rich idle mixture....  actually not bad.  Definately not black, but not white from running too lean either.  Right about in the middle ( tannish color ?) with a slight hint of the smell of fuel.

If you are coloring the plugs driving in town, it's likely too rich.  I'd start tweaking (or I suppose you could let the learning try to do it) Modern fuels will look lean in normal operation, and more than that reading plugs anywhere but the dyno and after a WOT run on the strip and shutting it down immediately will only give you gross information, too many circuits contributing to the coloring.

As far as the oil leak, looks like distributor, intake or front cover, I'd be going from easy to hard to figure it out

[cobracammer]

Thanks Ross.  Took the car out today to see if I could start at one setting ( idle) and adjust theAF ratio to get things dialed in.  With the idle, I had to adjust the numbers to get leaner and then every so often, adjust the ISC.  At 14.7 to 1, there was barely any unburnt fuel coming out of the exhaust.  The IAC was in the mid 20's and the car idled at 1000 rpm.  Perfect ( or so I thought!)  left my neibhborhood, and the car accelerated fine ( accel fuel still at +2), cruised perfecty ....... and then I tried to stop.  It would just stall when I put into neutral.  I could downshift because the rps's stayed high, but as soon as it tried to go back down to idle, it would shut right off.  So too lean!  Got back home with about 5 miles of fancy shifting/ revving, and got the computer back to 13.5 at idle.  Oil still dripping, so I may just take the intake off to re-do the sealant and at the same time, pull valve covers and check the lash on the rockers.  Unfortunately, I dont know when I can get to this because we are selling the house and moving again!  I guess for now..... end of forum posts!  Lol

[jayb]

Jason, don't pull the intake until you check that distributor seal.  I think that must be where it's coming from, because in the picture there is oil on TOP of the intake, right by the distributor hold down clamp.  If it was the front seal between the intake and the block, the oil would just drip down under the engine.

[cobracammer]

Hi Jay.  No problem.  In looking at the instructions for the distributor, there is only 1 o ring toward the bottom of the shaft going toward the gear.  There does not seem to be any seal on the distributor at the top ( near the top of the block/ intake.  Its definately getting worse as I can see it now dripping fown the side of the block from the "well" onto the oil filter adapter and then down to the driveway. 

[jayb]

The rubber seal is not internal, it goes on the outside of the distributor housing.  See the photo below:

[cobracammer]

Pretty sure thats whats missing then.  Ill check and also see if I can order a replacement ( only see ones for Chevy msd's on Jegs)  thanks again 

[jayb]

I doubt that it is missing, it is probably just scarred up or shrunken a little, and not sealing to the hole in the intake manifold.  If it is missing, my bad, because I installed the distributor. 

I've got extras, I'll send you one - Jay

[My427stang]

Jason,
I doubt you need 13.7:1 to idle.  My guess is the IAC is gummed up or sticking.  There should be no reason it needs that much fuel.

I know the numbers are just a reference point and we don't really know what ever cylinder sees, but if the engine was to temp and ran well, then something changed, it likely was not a mixture problem.

[cobracammer]

Thanks Jay.

Hey Ross,  I had it down to 14.7 :1...... and it didnt like that.  I was idling nice in the driveway with almost no fuel smoke coming out of the tailpipe, but when driving ( under load) , it would stall out at idle of as soon as I put it into neutral.  When i got home ( with difficulty) , i reset the ecu back to 13.5 : 1 .  But as a positive, it cruised well and accel well.

[My427stang]

I am not questioning your results, it just seems too much of a swing to me.  The IAC should respond and catch the idle regardless of mixture.  I wonder if you have had a stuck IAC all along?

[cobracammer]

Hi Ross,

No worries.  I saw in your last message you said 13.7 : 1.  I actually had it as lean as 14.7 : 1 to make the unburnt fuel smell (white smoke) to stop coming out of the tailpipe.  Each time I went leaner from the starting point of 13.5:1, I had to readjust and calibrate the IAC.  Was this wrong?  I wasn't sure if I needed to recalibrate the IAC by opening or closing it more based on the change in the AF target. 

So now I have it back to 13:5 to 1 at idle (factory setting).  I also have the IAC perfect as per the handheld so that its perfectly on target.  From this point, I am guessing I can go leaner , but the question is 2 fold....  How much leaner can I go (normally) and also do I need to readjust the IAC each time I change the Air Fuel target? 

When I started changing the AF target for idle, I did it slowly (in maybe 4 or 5 separate small changes) ending up at 14.7 to 1.  At 14.7 to 1 at idle, I re-adjusted the IAC so that it was back on target (done by adjusting screws on each throttle body).  The car sitting in the driveway was idling the same as it was at 13.5 to 1, hanging there at the target 1000 RPM's, but minus a lot of the unburnt fuel smoke.  I thought this was good, until I went for a drive.  At which point it would just stall as soon as I put it into neutral or got down to 2nd or 1st gear (downshifting).  I think what threw me off was that the 14.7 to 1 was good while at idle in the driveway, but then as soon as I started to drive, the 14.7 to 1 wouldn't work anymore.  lol

I would be curious (and maybe Jay can add to this) what his and other cammer engines AF ratios are?  Specifically idle?  I was thinking that due to overlap on this cam, plus the fact that this car does NOT have catalytic converters, that it will always smell a little life fuel (and possible always run a bit rich)?

Sorry if my previous post came off short.  I am usually replying on the road and via iPhone.  Waited to get home and type clearly on a laptop for this post :0)   Thanks Ross.......  I wont lie, this is all fun in a real PITA kind of way  LOL

Side note, As I was trying to get home the other day with the stalling issue, I pulled out of a gas station and immediately stalled.  The Saleen has vacuum assist brakes, so when it stalls, I have almost NO brakes.  LOL Pulled off to the side of the road and realized that I would have to keep the RPM's up while going home in order to stop it from stalling.  Put it in 1st gear, and while keeping on the throttle, let out the clutch.....  MY FIRST Burnout!!!!  Shame is was by accident, but I will take it! 

[newfalconowner]

my a/f idles at 14.7 every time. I haven't really gotten able to take it for a long drive yet,, as it gets dark here early now  and weekends are usually busy till late afternoon..