Hey guys, Let me start by saying this has been a big project of mine and the wife is gonna divorce me if I can't figure it out.

The Rig:
1989 F-150 Lariat 4x4 351W AOD NP208 3.88 gears with 32" and a leveling kit.

The setup:
1972 351W Block Worked professionally. Decked, New Cam Bearings, Bored 0.060 over originally .030.
Flat Top Hypereutectic pistons and rings to match.
Reconditioned Ford rods with ARP studs and nuts
Crankshaft reworked professionally.
Bearings to match above.
Crane Cam kit 4444232 with lifters
ProComp Heads (Leave Me Alone)
Intake Valve 2.02
Exhaust Valve 1.60
Combustion Chamber 64cc
Screw in studs.
1.6 Ratio Roller Rockers.
3/8 Pushrods
3/8 Push rod guide plates.
Cloyes Pre-stretched timing chain and gears
Edelbrock Performer Truck intake lower and upper.
24# Injectors professionally refurbished
Accel Yellow plug wires 8mm
Dizzy from big parts store (Worked fine before the build)
Autolite 3924
Shorty headers
1989 Crown Vic FlePlate for 351W to AOD
10" Torque Converter from PTC in Alabama.
AOD fresh with the 4r70w inners
NP208 transfer case fresh seals and nylon tips.

Parts that have been replaced recently
TPS
IACV
Battery and all wires
Starter
130 3G Alternator conversion
Water Pump HP
Radiator 4row aluminium
ECT both 2 wire and 1 wire
ATS
Harmonic Balance
ECM
Dizzy Cap and rotor

The problem:
With Timing set at 10* BDC the idle is around 1500rpm and I get popping through the exhaust. I pulled plugs to find that cylinders 4-6-7-8 were solid black and not wet were as the rest were perfect. The cylinder pressures are between 120-150 all cylinders are different but inside that range. If I set my timing to 10* ADC The idle drops to 750rpm and the moter evens out a bit but has little low end power. The motor also is not very smooth on idle the Rpm needle doesn't move but the motor is shaking under the hood. (I was advised with the cam I had the Idle wouldn't get rough.) I have a nice rich smell coming from the exhaust and a very faint white smoke VERY FAINT like un-burt fuel.

Steps Taken:
I performed the CAM break-in according to the sheet supplied with the Crane Cam kit.
I have checked the true TDC in relation with the harmonic Balanacer spot on.
I have set timing to 10* BDC
I HAVE DOUBLE AND TRIPLE checked my firing order
I have swapped different sets of wires, coils and plugs with no difference.
I have replaced all Vacuums lines with silicone and have double checked for leaks.
I have separated wires to prevent crossfire.
SEARCH and SEARCH and SEARCH Please understand I have been attempting to fix this issue for three weeks now and I have read through the forums and I am desperately trying to get this truck up and going its my DD and I am borrowing a vehicle now wanting to return it soon.

The question:
WHAT IN THE WORLD DID I SCREW UP?

 

You have 24# injectors with a computer that thinks they're 19#. Start there, swap out to 19#.

Also, pull codes to see what the computer says.

 

And, shortys with that setup .......

 

I am not getting any codes I have a reader and I am only getting transmission codes.

As far as the injectors Will it starve my truck for fuel with the bigger air or am I just paranoid?

The headers I have regretted sense the day I bought them.

Would the Injectors cause the high idle and popping at 10*BDC?

 

Also, I would rather change the computer than the injectors if possible is there a certain computer I could use to run the 24# Injectors? I understand big injectors are not a power gain unless the fuel is needed but the old ones were garbage and for what its worth I am tired of taking the intake off and ordering new gaskets through Edelbrock.

 

You will never get this combo it to run correctly on the original PCM. You no longer have the E4OD that was in the truck so you need to do a MAF swap with a Mustang PCM and then get a tuner like a Quarterhorse or Tweecer to dial it in. Did you put 3.88 gears in the truck? I didn't even think that was an aftermarket option for the 8.8, it's certainly not a factory option.

P.S. The backfiring is a concern and suggests some wiring isn't just right yet so I have to ask.. you are familiar with Fords cylinder number sequence and how it differs from the other guys..

 

I am curious as to why this setup will not run with the PCM. I have an AOD not electrical controlled. (I did the 4r70w build you suggested Conanski. thank you) I was careful to pick a speed density friendly cam. The intake and heads are the only other modification and both could be swapped onto a stock 351 without problem. I have wanted to avoid MAF conversion on this truck. I am familiar with the firing order and have made sure its not the problem.

I due apologize I meant to put 3.73 gears on the 8.8.

 

The computer cannot compensate for the 24 lb-hr injectors, coupled with the head, cam and exhaust work, you're probably way outside what the stock computer can handle.

Here's what I'd do if you really don't want to do the MAF swap and are willing to risk a couple of bucks: Go to a junkyard (or buy a re-manufactured from AutoZone) and get an 89-96 F250/350 computer for a 7.5/460. It will already be set up for the 24 lb injectors, and might actually run well enough.

 

Oh OK I see the head or the intake are fine by themselves but together too much.

Which do you think yields a better chance of success:
Going with 19# injectors or,
The 7.5 computer?

 

No, the intake, heads, exhaust, etc is not the issue...it will run fine with those.

Your problems are: the 24# injectors, no the computer will not compensate for them; and the trans - you had an electronically controlled transmission and its confused as to why it's not there.

Trans and injectors. Find a computer that will work with that trans, and swap out the injectors to 19#. I'd say swap to a 460 computer but I'm not sure how you'll work out the trans with that swap.

 

I will swap the injectors tonight and report back the findings. Thank you guys so much.

 

A 7.5/460 manual computer wouldn't care about the AOD, and an Automatic/E4OD one would set a bunch of codes, but would probably otherwise run fine.

 

Ok thanks to edelbrocks intake being considerably higher than stock I was able to swap the injectors with a fresh set of 19#.

The truck prior to the swap was set to 10*ADC because that is where it seems to like it. After the swap the truck idled better and the timing actually retarded to 0*. I readjusted the timing to 10* BDC the idle is still high around 1100rpm and there is still popping out of the exhaust.

I Checked my plug wires again and they are correct along with no crossfire issues. I ohm the injectors and 14.2 was the lucky number across the board. New sock screens along with O-Rings and what ever the little plastic hat is all new.

At idle it still jumps around like it is missing shaking and what not. New Plugs, New Wires, New Dizzy along with cap and button, New Coil, New Coil Connector, fresh injectors. I just want to find out which cylinder is missing?

There is still no codes being thrown at this time.

 

Ok, I stuck a long screw driver to the injectors and they are all firing like they are supposed to (crazy how you can test them that way).

If I unplug the #1 or #5 injectors nothing happens noticeably, but If I unplug the #2 of #6 injectors the idle evens out almost completely.

Guys please help I am completely stumped and the only thing I can think of is the TPS even though it is new. Would an improperly adjusted TPS cause this misfire issue?

Also due to the 24# injectors I am going to replace plugs perhaps I fouled one flooding all that fuel in the cylinders.

 

You have a myriad of problems; best to fix what you know is wrong and go from there.

You need a computer that isn't designed for an electronic trans. Do you have other issues? Seems so, but you know you need a computer. Junkyard 302, 351, or 460 computer with non elec trans