Why is my 3.2 only lean on the left side?

[johnny spies]

I need help>did 2.7 to 3.2 conversion. On the starter, I know where the black and red go but I only have one yellow . Where does it go on starter?

Also, I have 2 wires in its on wire loom coming by the starter. They are yellow/green and brown/white, where do these two go

Thanks for your help. I am ready to start engine but don't want to until I get these wires figured out.

[cgarr]

Just pulled the engine because its winter and nothing to do and still wanted to check the lean condition and why I am still using oil with a rather fresh rebuild! This may be the lean condition, see the pic of the crack gasket on #2 Left side and note the excess oil in the #6 intake. Will report as soon as I get the cylinders off.

[aston@ultrasw.c]

I have the same condition. Dual exhausts, left and right bank are entirely separate.

At idle - left is 14.4, right is 12.9.

At WOT the gap narrows to just a point or two e.g. 4000r left is 12.73, right is 12.76.

I know the OP found a crack in #6 but I just replaced all the seals/gaskets etc....

The fuel pressure is correct but I can only measure at the left bank of course.

Now I have figured out that it's only at idle I am less concerned. I can continue to work on the WOT tuning.

But has anyone else see this diff at idle?

[ischmitz]

Aston,

given that you have been adjusting the AFM I can see a couple of different scenarios that can explain what you are seeing:

Most likely you have a vacuum leak on one of the intakes on the left side. During you adjustments you have richened up the entire engine at idle so that the leaky side comes in just right while the good side comes in too rich at idle. Remember that the intake vaccum is greatest at idle and even small leaks at the intake gaskets will make a big difference. Once you open the throttle the amount of air coming in through the intake leak becomes small in comparison to the total amount of air ingested. That's why the banks even out.

Another possibility is that you have one leaky injector. That you can check qickly by swapping them from left to right. Didn't you do that? I have to re-read your other thread again.

Less likely you have one barrel on the right that isn't firing at all due to poor compression or orther issues. You can quickly check that by pulling each spark plug wire at idle. Each pull should make the engine idle note change. Else, check that all three individual exhaust ports get warm right after you start the engine.

Ingo

[ischmitz]

OK, I re-checked your other thread and you did swap injectors. That sort of leaves air or compression. Try spraying starter fluid or propane to each intake runner while the engine is idling to hunt for leaks. And do a leak-down and compression test after making sure the valve adjustments are fine.

Ingo

[aston@ultrasw.c]

I did loook for leaks with an acetlyene nozzle but I may have to try starter fluid. I just replaced every gasket, spacer and seal in the inlet tract, but that doesn't stop any from leaking.

I also checked the temp of each header after a short run and they all seemed to be at the same temp.

Maybe it's time for a leak down test.

[scarceller]

I've been helping on this one also, I'm with Ingo on checking to be sure the gaskets between intake runners and heads are not compromised. Best checked with starter fluid can with a straw to spray the fluid down near the area where the gaskets are located.

One other possible cause could be improperly timed cams. If one cam is opening intake valves sooner than the other you would also get this same behavior. Question is did this engine ever run balanced? or is this a new engine (just built) or a used engine that we have no history on? I suggest compression and leak down be done as well as double check cam timing.