injector cleaning and calibration

For some reason the 55 got leaner throughout the weekend. Started at 12.3-12.5 Fri. on the dyno to 13.5-13.8 in the last race on Sun. It also is not running very good at lower RPM's. WOT is fine but still about 10-12 hp down on power from every other engine I have had. I tried to use the old block and just honed the bores and put in new Pistons, rings, and rod inserts. I'm pulling it out this weekend. Have a new (not rebuilt) bullet on the way. I will clean the MAF or replace it. And I just wondered if doing the injectors is worth doing. Still not convinced. Something is wrong and if I can't figure it out prior to Cresson I will have to skip it.

I wouldn't be leaning toward injectors personally. Was the weather different between those 2 events? In open loop, my cars all suck at DA correction. They rely heavily on the 2D map that affects open loop fueling which I believe is load vs coolant temp applied to all RPMs. This is how I've seen the OEs do it, but it's possible Ford did it different on the 4.6. I wouldn't count on it though. That's why mods like cams and headers sometimes really throw the car for a loop (mostly when they affect the VE curve, if it's a global bump the ECU can generally compensate). That's why a fuel pressure change only affects WOT AFRs for a short period of time if you're closed loop. The car applies what it learns in closed loop to open loop. Are you sure something didn't happen that the O2s are picking up on like a vacuum or exhaust leak? Did you monitor both banks for AFR or just 1?

What are your short term and long term fuel trims? Your OBD reader will tell you that.

All this crap makes my head hurt. I installed new O2's and no change. The wideband is on the right bank but after the X pipe. I have not looked at fuel trims. I was getting P1130, P1131, P1150 and P1151.

Jerry

Looks like the same fault throws all of those codes. My buddy says with the BMW it is very common to have vacuum leaks and the dealerships use a smoke generator to find them. Cigar smoke through a piece of hose works too. Good luck Jerry, I'd look for something mechanical after the re-assembly if it was good electronically before, just my two cents

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Originally Posted by dtanker65

Cigar smoke through a piece of hose works too.

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Next race features a cigar and brandy corral with vacuum leak detection

There is something going on with the 55 and I'm like Jerry that I don't know about fuel trims and what not. But I don't think it's the engine as it's something fuel/ignition/electrical I think. Why are you pulling this engine now Jerry? Did you clean the maf or inspect it. Did the camera work? I hate to see you pull it to find it was a vacuum leak or a loose connection.

Look at the fuel trims, and while you're at it look at all of the other sensors to make sure they are reading right.

If a bank reads +10% at idle that means it's having add 10% more than usual which would indicate vacuum leak, bad/low injector, fuel pressure, mass airflow or manifold pressure as possible culprits.

Doesn't your 4.6 have a variable computer controlled pressure regulator?

You can read all this off your phone and a Bluetooth obd adapter which I think you guys have. Bummer you're not in Houston as we have 17+ dynojet and they'd do a good job of helping figure out what's going on at WOT/high rpm if you can't figure it out in idle or driving around the block.

No sense trying to poke at it without reading the wealth of data your computer tracks and makes available via obd2, just IMO.

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Originally Posted by Pranav

Look at the fuel trims, and while you're at it look at all of the other sensors to make sure they are reading right.

If a bank reads +10% at idle that means it's having add 10% more than usual which would indicate vacuum leak, bad/low injector, fuel pressure, mass airflow or manifold pressure as possible culprits.

Doesn't your 4.6 have a variable computer controlled pressure regulator?

You can read all this off your phone and a Bluetooth obd adapter which I think you guys have. Bummer you're not in Houston as we have 17+ dynojet and they'd do a good job of helping figure out what's going on at WOT/high rpm if you can't figure it out in idle or driving around the block.

No sense trying to poke at it without reading the wealth of data your computer tracks and makes available via obd2, just IMO.

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Do not talk to me while you are in the mountains skiing. I can't hear you......la la la la la la la la la la la la

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Originally Posted by ShadowBolt

All this crap makes my head hurt. I installed new O2's and no change. The wideband is on the right bank but after the X pipe. I have not looked at fuel trims. I was getting P1130, P1131, P1150 and P1151.

Jerry

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I'm no engine guru, but does having the wideband after the X-pipe throw any flags to anyone else? I'm thinking it is too far away from the engine giving the exhaust time to cool a bit and affect readings. I'm also curious about the crossing of the exhaust streams causing erratic or erroneous readings.

I could be way off base, but every factory O2 sensor I've ever seen is relatively close to the exhaust port. Kinda like taking pollution readings either near or far away from the source.