Truthfully, I wouldn't have said that If I thought I might be wrong, I wouldn't want to give you guys an opinion

But, my 4.9L ran extremely well (had 128K when I got rid of it), I did go to 3.55 gears later with a LS, and it made it pull hills even better (1st seems extremely low after that). Mine was a 4x2 with 33's on it, so 3.55 seemed neccessary. BTW, 12/hr injectors for Ford are grey, the 19/hr injectors are orangish yellow for the F150's. Hope this helps.

 

This right here is true, I bumped mine from 10 Deg to 12 Deg, did seem to help a bit.

 

http://www.bigblocksix.com/Eddie/injectorswap/
Well, can't be too careful. Terrorist stuff! Exploding underwear, then talkin everybody w/ I-6's into Modding into Gross polluters, installing larger injectors, only to have them confiscated & destroyed by our own Federal government. Diabolical? Sounds crazy & far fetched? I hope so, it's the best I could do off the top of my head. While I've had a bunch of 8's, I've only had 1 injected I-6 back in 87'. Anyway, Good to know. How could I ever have doubted you? (You have to admit, 12 to 19 is a huge leap!)

 

I know, I bet the 4.9L motors would run a bit better with 19 lb/hr like the V8's, but the fuel rail runs so close to the exhaust manifold, that when something is under higher pressure, it's harder to turn to vapor when heat is applied (same concept I use here at work for running the distillation columns, reboilers for heat, vacuum pumps for less pressure), less pressure, easier to vaporize when heat is applied. Hope that helps. Gotta hand it to Ford for thinking of that

 

I've spent alot of time working on Boilers (low pressure/125psi) & Vapor recovery/distillation units. By trade, I do commercial/industrial machine repair. Actually, vapor lock was very popular in the early F/I days. "Popular" might not be the right word. If I had a MAF engine, I might consider an adjustable fuel pressure regulator, but MAP's are a little to non negotiating.

 

You understand exactly what I mean then My ealry FI engine was a 1986 F150 5.0L, but never experienced this but the design was different than a 4.9L FI. I think I like MAF engines better myself if I had a choice. Seem to fine tune better, my 1996 F150 4.9L had both MAF and MAP sensors

 

If you liked 12 BTDC, you'll love 14 BTDC. If your worried about Ping, run stock Motorcraft Copper cores. They're a cooler range plug & much more forgiving. Heatwise, anything above what's required to effectively ignite the fuel is counterproductive! It's alot easier to avoid the temp Ping threshold, then to drop below it, after it is reached. Especially w/ x2 Plats &/or other exotic alloys. I run my stock Motorcrafts at 16 BTDC, at 80MPH for 700 miles between refills on my Oregon trips (after repairing my cruise control which will make the drive more tolerable & a recent $516. Citation for 15 mph over, I think 80mph for 700 miles is a thing of the past). Also, w/ an Ignition system upgrade, you can stretch your gap which trades intensity (w/ heat byproduct) for spark kernel exposure to effectively Fire. I personally believe, more effectively w/ alot less counteproductive, unnecessary, excess, hard the dispell temperatures within the combustion chambers. That's my 2 cents plus tip!

 

IMO, that's probably your issue. What size are your tires?

 

1987 F-150 with 4.9L and dual tanks has (3) three electric fuel pumps. Each tank has an in-tank booster pump for priming the fuel tank selector valve assembly. This selector valve reservoir feeds the high pressure in-line pump located on frame rail before the engine. ------------------------------------------------------------------------

 

I agree, I put the Motorcraft copper in my 2001 5.4L, I know I "may" have to change them more frequently, but I have it down to an art. I already bumped this truck up 1.5 BDTC for more power on my edge programmer. No pinging from the great motorcraft plugs. I put them in my vehicles, regardless of make. Well, I wonder if they make some for a 2009 Hyundai Sonata that has iridium?