Fuel pressure looks good

Then your Lean code and driveability issue may be from a manifold gasket. Again, I have found the spray method to be unreliable on a modern EFI engine. Just my experience from working on these things for 20+ years.

I do not think your GT40 intake is not compatible with the Speed Density system. It's just the process of elimination. I did not view the video yet...

One other thought. I recall from the outer edges of my memory the EGR from a Mustang has a large orifice size than the truck version. A larger orifice is allowing more exhaust gases into the intake than the truck PCM is programmed for. Perhaps that could be the pinging issue at high speed. Prime area for EGR operation. That would not account for the hesitation issue at lower RPM.

 

Just blocked off Egr.

Just compared the two EGR valves, the truck valve is about 1/16" smaller in diameter at the opening - however they use the same positioner and have the same amount of valve/bladder excursion, and the valve plug itself is the same size. in my mind, if it was an issue with orifice size, the computer should be able to compensate across different inlet sizes given the valve was the same size, as that is the bottleneck. I am not aware of the adjustment resolution the computer is capable of, most of my experience in automation is 4-20mA signal with industrial automation. I have also replaced lower and upper gaskets twice Over the past year. No change. This truly has me stumped.

Edit: just drove the truck, hard to put it under load as it is wet and now is breaking traction. Did not hear pinging down low like I heard yesterday - blocking off the EGR has certainly done something to it. Almost screwed up royally, went to take off and realized I hadn't reconnected the tv cable to the TB armature, that could've been an expensive lesson.

Engine sounds better under acceleration, more of a roar than a bogging out sound. Certainly has more power in acceleration, however off idle hesitation is still there. It may be an issue with the difference in between the single 65mm throttle body and double 51mm throttle body blade, at lower throttles and their throttle resolutions.

 

What have you done with the smog system on this truck? Is it still there and functional or partially or completely removed?

 

Everything is still there and functional. smog/A.I.R. injection pump is about 18 months old, all piping is intact and all vacuum lines replaced with rubber. It does work, no codes for smog besides EVP.

Edit:
Well I hope the damn thing works at least. Everything is there and isn't throwing a code.

Edit2: Drove around for a bit. Pinging is still there, most prevalent between 2000-3000RPM. EGR blockoff did not help. Double checked wires and cap resistance, way below 100 Ohms. Thinking about maybe swapping back to 180* t-stat, the more I look at it the more I feel like going back to E7 intake despite its problems.

 

Keep in mind the computer uses voltage feedback and it has no way to measure actual flow. Therefore a larger orifice EGR is going to flow more exhaust gas than a smaller one. It's probably a moot point since you still have pinging with the EGR blocked off. On the other hand the computer is advancing the timing thinking the combustion temps. are lower.

Personally I think you have a vacuum leak somewhere that is the root cause here.

 

Backed off timing quite a bit, bogging like crazy. pinging has gone away. Apparently my laser thermometer is wimpy, saying my skin is 150*F.

Getting code 42(rich), logically.

 

something funky is happening, I don't think its egr related at all, but the evp out of range certainly should be addressed as that will cause drivability issues and may be compounding the problem. it is highly unlikely to be the root cause, and I'd be shocked if it were.


o2 sensor not operating correctly shouldn't be the issue either, since its reading lean and ping is present. so, at this point its safe to focus solely on what could be causing the lean issue and assuming the o2 reading is accurate. afterall, the computer should be trying its damndest to compensate for the lean condition but cant.


is your hvac control inside the cab functioning properly? its not uncommon for the lines behind the bezel to be completely gone by now, if the controls are hesitant/non functioning that could be the source of your air.


IAC-if the valve was stuck wide open, id suspect the idle would be erratic while the computer tried to compensate, but its certainly worth a shot.


TPS and EVP sensors both have simple max and min values to be read with a volt/ohmmeter, you seem like you are not unfamiliar with such tests so you simply need to look up the values. Haynes manuals have them, as well as other manuals, but google should be able to provide them or someone will chime in with them here.


I think you'll have a "voila" moment when you find the problem. in order for it to have drivability issues with ping, it has to be something substantial and obvious once the proper attention is given in the right area.


all else fails, get a donor ecm to swap in and see if it changes. its not a bad idea to unhook the battery for a bit and let the ecm's running memory reset. unhooking the o2 sensor will put it into open loop also, which could provide some value in the form of diagnostics, considering if it does clear up in open loop then you likely have a simple sensor problem.

 

Does anyone have a top down picture of a correctly timed distributor?

Was at the shop today talking to one of the guys when he mentioned I might have stabbed the distributor a tooth off.

 

There really isn't "stabbing it a tooth off". It can be on any tooth, and dizzy can be in any position, so long as there is enough space to turn it to be timed correctly before the ignition module (or the wiring harness for the fender mounted module) hits the thermo housing or the ? Valve cover (not sure without looking at it) ? On the other other side.

Best way to confirm is to check timing with a light, if your timing marks are legible. If not, there are other methods.

It's possible that your pip is failing inside the distributor, causing the computer to go haywire. I'd say it's unlikely, when the pip fails it normally prevents it from running, but certainly a possibility. It could also be working fine, but caked with crud, altering the signal.

 

New distributor and PIP.

 

What brand dizzy? What color ignition module?

So, how long did you drive this thing before you started having the hesitation and detonation problems?

 

Motorcraft distributor, Grey ignition module.
I'm on my 3rd or 4th module, cant remember.

Truck ran great before the GT40 swap.

 

Just wanted to be sure you were familiar with the modules, and I bought a "motorcraft" from rock auto that lasted me only a couple months after my build before the pip failed, but i honestly don't think pip is the problem, I'm just throwin stuff out there.

And it never ran good after the swap?

What'd you plug the base of the egr valve with?

 

It had its moments, always felt like I could never get timing right - at best it would run rich down low and lean out up high.
I'm thinking when Spring break comes around I'll port match my E7 intake and put it back on.

I plugged the EGR base with a cut out soda can.
Also pulled the plugs, thought possibly When I put them in I screwed up to gap but they were all a perfect .045".
Was at home this past weekend and picked up a 180* stat and my spare MAP sensor.
Considering pulling the upper and lower to check out gaskets again... Really at a loss.

 

does it run good wot, or is it too bad to try?

Pcv can get stick open, which would then generate a large vac leak, lean condition, and perhaps detonation as a result. It'd likely clean up at wot, but under part throttle/off idle could cause issues.

I know you're not a fan of the tsunami wave removal (no sane person is), so you can test the pcv very easily without removing it. Did you happen to give the valve a shake when you had it out?

Besides all that I don't know what else to say without continuing the interview / essay.

Also, a penny works better than a soda can. People have been using soda cans successfully for who knows how long, but a penny is a more positive plug considering it's rigidity.