1998 Explorer Setup (not in an Explorer)

[FloridaNative516]

I am a new member and look forward to learning from this forum. I dont exactly have an Explorer, HOWEVER, I have an engine and tranny combination from a 1998 Explorer that I've converted into a smaller car.

I'm currently running the following:
302/V8 setup as a 1998 Ford Explorer.
80mm Ford Mass Air
65mm Acufab Throttle Body
Distributorless Ignition w/coil packs
19 pound injectors (tried 24 lb but fuel pressure too low at idle)
155 in tank fuel pump
Edelbrock Intake (Performer RPM)
Mild Wolverine Cam (assuming it's a Blue Racer WG1190)
ECM: EEC-V NRT1 short code with SCT Superchip installed
ECM Part No. F87F-12A650-AVB with Catch Code NRT1
Wiring Harness from Ryan at FordFuelInjection.
4R70W AT with 2800 Stall converter (tranny pin setup as 7-pin connector for 98 version)
8.8 Rear end

The problem I am having is during deceleration the computer appears to be going into a open loop / close loop condition creating an engine surging. This looping is continuous until you decel to about 30 mph and then it goes into close loop and runs smooth. Also noticed that the tranny shifts smoothly between the primary gears but dropped quickly into OD. Upon deceleration you can feel the car instantly jump out of OD into the next higher gear but as soon as you touch the gas pedal, it shifts back into OD.

The shop I'm working with is at a lost with this phonomena. At the dyno shop he checks the strategy of the ECM and it gives a 7-digit code of "RAAD4G8" and cross-referencing it comes back with a catch code of MCR2 (not NRT1) though the computer has a sticker with NRT1 code (another dilemma).

Anyone in the Explorer realm have any knowledge of this type of encounter?

Any help would be deeply appreciated.

Warm in Florida.

 

[cjones101812]

the ECM probably was flashed (by the dealer) which will change the code. your programmer should be able to change HIS program to compensate for the flash. he will use the 'mcr2' code as a start point that the ECM has.

 

[Turdle]

Lets back up a minute--
when you say "goes into over drive then the next highest gear" makes no sense, since the overdrive gear is the highest gear.

 

[FloridaNative516]

Thanks for the replies. We did try to run an MCR2 tune and it would not run properly. Idle's A/F ratio looked great but as soon as you went WOT, it would jump to 18+ lean and we would back off immediately. The ironic part of this is when we run the NRT1 tune it will run with an acceptable A/F ratio but it will only run properly using the high-test fuel tune. If we try to run a 87 octane tune it will not run properly.

As far as the other thread about the highest gear, I was referring to the next hightest gear ratio (3rd gear) as opposed to OD which I call the lowest gear or lowest gear ratio.

The dyno tuner also cannot lock out OD to run a tune in 3rd. The PCM should be able to be programmed for setting shift points and OD lockout but the system will not take any input though the programmer he uses (I think Xcal2). He has no problem with other EEC-V vehicles that come in for dyno/tune.

I'm anticipating a change back to EEC-IV using a A9L computer and sticking a Tremec TKO or equivalent 5 speed manual tranny and a nice MSD billet distributor.

I've recently encounted a real bad harmonic vibration at 50+ mph that feels like its going to shake the car apart. It is more prominent during deceleration but is there during accel and decel. Its not the engine because I can rev it up sitting at a light and there is no vibration. If I'm going 50+ mph and drop the tranny into neutral, the vibration is still there. I've aligned the car and balanced all tires. The vibration is NOT in the steering wheel but feels like its all around me thru the vehicle. I'm narrowing it down to tranny, driveshaft, or short shafts. Plan on lifting it up and checking for play in the driveshaft to see if any U-bolts are loose or mis-aligned.

Never a dull moment with this monster.

Warm in Florida.

 

[jah81592]

I would tune this vehicle with the read strategy pulled from the computer rather than the boxcode. This would be my starting point. The driveability concern you voice I believe would stem from various conditions (head and cam) which can definately be corrected in the tune. I get cammed vehicles all the time which are jerky when they arrive at the shop and when they leave it is notably smoother. Furthermore I cannot understand why the trans cannot be locked into third. There should be full control over this function in this pcm. What is the MAF meter off of? This is real important as well. -j

 

[FloridaNative516]

I would tune this vehicle with the read strategy pulled from the computer rather than the boxcode. This would be my starting point. The driveability concern you voice I believe would stem from various conditions (head and cam) which can definately be corrected in the tune. I get cammed vehicles all the time which are jerky when they arrive at the shop and when they leave it is notably smoother. Furthermore I cannot understand why the trans cannot be locked into third. There should be full control over this function in this pcm. What is the MAF meter off of? This is real important as well. -j

Thanks for the reply. We tried to tune using the MCR2 catchcode based on the read strategy and we could not get the car to run hardly at all. When we put the NRT1 tune back in set for high octane only it would run. The MAF is a Ford 80 mm and when checked it appears to be functioning properly.

The wiring harness was custom made from Ryan J McCormick of RJM Injection Tech (also known as Fordfuelinjection.com) and was made to match a EEC-V NRT1 setup. On the OBD-II port there are only 7 wires utilized on the 16 wire connector at pin locations 2, 4, 5, 7, 10, 13, and 16. We found some of these loose and soldered them back but still can't seem to get things to function or take input for OD lockout or shift points. The wiring harness is a all in one harness so there are no separate harnesses for injectors or O2 sensors. The IAB, VSS, TPS, etc. all seem to be functioning properly.

I'm using an Edelbrock Performer heads and intake and the cam is a small Wolverine Cam (assuming a Wolverine / Blue Racer WG1190). That assumption is because I picked up the engine already assembled.

I'm running out of ideas so thats why I'm thinking of going back to a 5 speed and EEC-IV system. I'm more familiar with the old school (carb, etc) but I choose to keep mid school (EFI) but go to a more familiar EEC-IV setup.

Again, I appreciate your replies. I have some additional drivetrain issues (high vibrations not in wheels or steering) so I'm working on each one independently. However, I think if I go back to a 5 speed tranny which most likely will require a shorter driveshaft, I think the vib issue will be taken care of in the process. (Guess its called "process of elimination")

Warm in Florida.

 

[jah81592]

If the vehicle won't run or shift right then I would have to point to the harness or computer. HMMMM! Strange.....