Not able to accelerate after about 25 to 30

[BIG_RanGer1121]

Been on this site for a long time, never posted anything though,so I've been building this for a few years now, it's a 91 ext cab what was a 3.0l Vulcan, now a 302 v8, I know about the explorer fead, I'll be changing to that in the future, currently it runs and drives, when i get going about 30 or 40 it starts to sound like I lose 2 cylinders, it starts bucking from what it seems and I can put it into neutral and it'll go back normal and act fine for a bit but when i put it in gear going that fast it does the bucking again any one possibly have this problem before or, know of a way to fix it anything is appreciated lol .

 

[dvdswan]

Was the 5.0 from a flex-fuel vehicle?

BTW, welcome to the site.... finally.

 

[BIG_RanGer1121]

I got the motor from 96 f150 that dude was selling online, he had it seeing for a year in barn,
Thank you for the welcome lol this is my go to site for stuff on my truck haha

 

[BIG_RanGer1121]

One of my mechanic friends said it was a fuel problem, I just tried to do another drive and it did the same, being truthful I modified my v6 harness on From my original one by cross referencing them as close as I could to each year but I'm not sure that it's working like I wanted fully

 

[RonD]

I know about the explorer fead, I'll be changing to that in the future

What does this mean?

So you have a 1996 fuel injected 302 using 1996 PCM(computer), EEC-V 104-wire
Whats the V6 wiring harness from?
1991 Ranger used EEC-IV PCM 60-wire, so that harness wouldn't plug in to the 1996 EEC-V


Don't quite understand the "neutral thing"
This is a manual transmission, right?
So when engine is stumbling you can push in the clutch pedal and it starts to run normal, you can REV it, but as soon as you let out the clutch it stumbles again


Generally speaking when engine RPMs and/or power is limited there is a fuel shortage, or maybe exhaust blockage

 

[BIG_RanGer1121]

What does this mean?

So you have a 1996 fuel injected 302 using 1996 PCM(computer), EEC-V 104-wire
Whats the V6 wiring harness from?
1991 Ranger used EEC-IV PCM 60-wire, so that harness wouldn't plug in to the 1996 EEC-V


Don't quite understand the "neutral thing"
This is a manual transmission, right?
So when engine is stumbling you can push in the clutch pedal and it starts to run normal, you can REV it, but as soon as you let out the clutch it stumbles again


Generally speaking when engine RPMs and/or power is limited there is a fuel shortage, or maybe exhaust blockage

No it's not a 96 pcm it's an older one for an 88 to 93 or 4 I believe, I can't remember quite what the number said when I looked it up on the comp, the fead is front end accessories drive , the explorers had a 302 v8 with a shorter water pump and accessory mounts that worked better in the ranger

 

[BIG_RanGer1121]

An yes partially on the second question about the stumbling when back into drive
I'm using a 60 pin v8 comp for it not the 104, but I've been doin researching an found some interesting stuff when it came to the auto computers vs the manual the conversion isn't that hard

 

[RonD]

So computer is Speed Density using MAP sensor, not variable using MAF sensor?

Its an automatic, do you know the model, E4OD
Does it have Neutral switch(DTR or TRS) hooked up?
Computer limits RPMs if it thinks trans is in neutral, and from your description trans "thinks its in neutral when in D", then "thinks its in gear when in N"

 

[BIG_RanGer1121]

Yea it's hooked an works fine an it's a manual computer I saw the five speed it came from sitting in the guys garage, he showed me the truck he was building

 

[RonD]

Confused,

......the stumbling when back into drive

So a 1996 EFI 302 with a manual transmission
Run by a 1988-1993 EEC-IV from a 302 V8 manual vehicle
Using a V6 harness with 2 ground wires added for the 2 extra injectors

Spark system?
EDIS-8
Or distributor

So the clutch switch is the Neutral switch, is that wired in for Neutral?

 

[BIG_RanGer1121]

Being honest I have the neutral safety switch wired in so I can start it without using the clutch, I know it sounds dangerous but it's something I grew to remember and use often, kinda like a security on it, it's a normal distributor nothing special yet on the engine expect the explorer intake manifold and plenum, what do you mean on the extra 2 grounds wire? Would those just be normal grounds or is it something specific for each injector,
I'll post up a pic of it before long , pretty proud of it even if it running like crap lol

 

[BIG_RanGer1121]

The other 2 injectors are branched off of 2 other injectors that are near by, I've been feeling like it isn't wired in like I need to be

 

[RonD]

Injectors all get 12volts with key on from a wire they all share
Computer has one ground wire for each injector to open it, sequential injection, follows the firing order

Earlier EFI computers did use Batch Fire, just 2 computer grounds each opening 3 injectors(V6) or 4 injectors(V8)

V6 engine wiring would only have 6 injector plugins, V8 computer would have 2 extra
Look at the original injector wires
There would be a red wire on each thats the 12v
If each injector has a different color Ground wire(6 colors) then its a Sequential injection harness
If there are just 2 colors shared then its Batch Fire harness

Mustang V8 wiring here: https://www.stangnet.com/mustang-forums/attachments/88-91_5-0_eec_wiring_diagram-gif.113534/

It has the 8 different wire colors for injector grounds

You could add those 2 extra wires to computer connector

302 has this firing order, applies to injectors as well as spark plugs, 1 5 4 2 6 3 7 8

1 thru 6 wires should be there, just in the wrong places if still in the V6 harness tape
1, 2 and 3 would be on the passenger side and correct, but 4 would have to be moved to passenger side rear injector
Then 5 and 6 at the front of drivers side
7 could be hooked to 6 and then 8 to 3

But I doubt thats your issue

 

[BIG_RanGer1121]

Would it run with either firing order? Cause, I'm pretty sure it's the ho firing order that I'm currently running

 

[RonD]

If its not an HO engine and you have a distributor then you need to run the above spark and injector firing order
This has to do with the cam installed

If it was distributorless, using Waste spark coil packs, then wouldn't matter