• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

1995 4.0 missfire


chiri

New Member
Joined
Mar 5, 2019
Messages
14
Reaction score
1
Points
3
Location
chile
Vehicle Year
1996
Make / Model
ford ranger
Transmission
Manual
Hi, Looking from some input from the experts.

Have a 97 ranger 2wd with a recently swapped Explorer 4.0, complete engine and wiring. Only pending issue is I am running a MT with a AT computer.

Its running quite well but at wot and around 3.000rpm, it starts missing on some cylinders. If I return to Idle it runs ok and can accelerate VERY careful but any more than feathering the throttle, return the missfire at all rpms.
This stays as permanent until I cut the engine and start it again and everything is normal until it comes again. Can drive all day if I am careful, this happens always when near WOT and always over 2.000rpm.

Changed the ignition coil but no change.
Tach keeps working during the missfire so this discard CKP failure(?)
Fuel pressure a little lower than specs but ok, no change during the missfire.

Any idea what to look for?
 


franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
3,477
Reaction score
1,791
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
Pull any codes yet? Some will not give you a check engine light. Since this is a swap, was the check engine light hooked up?
 

gaz

Well-Known Member
U.S. Military - Veteran
Joined
Sep 21, 2007
Messages
1,460
Reaction score
684
Points
113
Location
Wa, Bremerton 98310
Vehicle Year
1987
Make / Model
Ford
Engine Size
87Ranger Endrigo 2.9l, 87BII Endrigo 4.0l
2WD / 4WD
4WD
Total Lift
Ranger 5" (1½" suspension), BII 4" suspension
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 33"/4:10LS, BII 33"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
@chiri
Hello,
The fuel pressure should not be a little low. How did you check/measure the pressure?
 

chiri

New Member
Joined
Mar 5, 2019
Messages
14
Reaction score
1
Points
3
Location
chile
Vehicle Year
1996
Make / Model
ford ranger
Transmission
Manual
@chiri
Hello,
The fuel pressure should not be a little low. How did you check/measure the pressure?
I am using a pressure gage on the pressure hose, have 28/40 psi.
 

chiri

New Member
Joined
Mar 5, 2019
Messages
14
Reaction score
1
Points
3
Location
chile
Vehicle Year
1996
Make / Model
ford ranger
Transmission
Manual
Pull any codes yet? Some will not give you a check engine light. Since this is a swap, was the check engine light hooked up?
have tried but cannot connect my scanner, "cannot establish connection" or something, a friendo will try with a more capable one.
 

gaz

Well-Known Member
U.S. Military - Veteran
Joined
Sep 21, 2007
Messages
1,460
Reaction score
684
Points
113
Location
Wa, Bremerton 98310
Vehicle Year
1987
Make / Model
Ford
Engine Size
87Ranger Endrigo 2.9l, 87BII Endrigo 4.0l
2WD / 4WD
4WD
Total Lift
Ranger 5" (1½" suspension), BII 4" suspension
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 33"/4:10LS, BII 33"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
@chiri
I recommend determining why your fuel pressure is dropping. It should be constant while running and should not bleed off after shutdown; because I have seen the pressure solid after months of sitting, I know that it requires a failure to perform different.
 

2011Supercab

Well-Known Member
Joined
Dec 10, 2021
Messages
443
Reaction score
479
Points
63
Location
Washington
Vehicle Year
2023
Make / Model
Toyota Tacoma
Transmission
Automatic
2WD / 4WD
4WD
Only pending issue is I am running a MT with a AT computer.
And there's your problem.

Your computer thinks the engine is in park or neutral and is limiting the engine to 3,000 rpm

You need a computer for a manual trans or find someone that can reflash your current one to remove the auto trans..
 

SenorNoob

Well-Known Member
TRS Event Participant
Joined
Oct 24, 2012
Messages
2,488
Reaction score
632
Points
113
Location
Middle Tennessee
Vehicle Year
1988
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Total Lift
1.5" Front + 4" Rear
Tire Size
245-70-R16
I'm surprised it took this long for someone to say that. Fairly well known issue. Ford tried to stop people overrevving their automatic trucks in neutral/park.
 

chiri

New Member
Joined
Mar 5, 2019
Messages
14
Reaction score
1
Points
3
Location
chile
Vehicle Year
1996
Make / Model
ford ranger
Transmission
Manual
thank for the answers, I am changing the fuel pump, seems to be leaking back, also the regulator.

Regarding the computer, somewhere I read there is a hack you can do as a temporal fix, puting a resistance to mimic the transmission in gear, does anyone know about that?

I am looking for a MT ECU but they are not easy to find here, nor someone capable of reflash the one I have.
 
  • Like
Reactions: gaz

franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
3,477
Reaction score
1,791
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
I took a wild guess that you had a 1999 explorer swap with the 4R70W transmission. Here are some diagrams. One of them shows a transmission switch. Another shows the digital range switch and it does have a resistor in it.
 

Attachments

franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
3,477
Reaction score
1,791
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
This one here is 270 ohms.

 

gaz

Well-Known Member
U.S. Military - Veteran
Joined
Sep 21, 2007
Messages
1,460
Reaction score
684
Points
113
Location
Wa, Bremerton 98310
Vehicle Year
1987
Make / Model
Ford
Engine Size
87Ranger Endrigo 2.9l, 87BII Endrigo 4.0l
2WD / 4WD
4WD
Total Lift
Ranger 5" (1½" suspension), BII 4" suspension
Total Drop
Ranger 5sp, BII A4LD
Tire Size
Ranger 33"/4:10LS, BII 33"/3:73LS
My credo
Deengineer until it is how Blue Oval should have sold it!!
@chiri
I have only had a 2 stock Ford hi pressure fuel pumps go bad but when the 1st one died, I bought an off brand replacement...it did not carry the torch well.

All of the stock Ford fuel pumps turned out to be made by Bosch. Since learning this I will only buy a Bosch replacement. In my experience, it is worth the couple extra dollars.
 

chiri

New Member
Joined
Mar 5, 2019
Messages
14
Reaction score
1
Points
3
Location
chile
Vehicle Year
1996
Make / Model
ford ranger
Transmission
Manual
I took a wild guess that you had a 1999 explorer swap with the 4R70W transmission. Here are some diagrams. One of them shows a transmission switch. Another shows the digital range switch and it does have a resistor in it.
Thanks, I am using a 95 Explorer but this is useful info, where can I get diagrams like that? the EVTM?
 

chiri

New Member
Joined
Mar 5, 2019
Messages
14
Reaction score
1
Points
3
Location
chile
Vehicle Year
1996
Make / Model
ford ranger
Transmission
Manual
@chiri
I have only had a 2 stock Ford hi pressure fuel pumps go bad but when the 1st one died, I bought an off brand replacement...it did not carry the torch well.

All of the stock Ford fuel pumps turned out to be made by Bosch. Since learning this I will only buy a Bosch replacement. In my experience, it is worth the couple extra dollars.
I am using the Ranger 2.3 pump(no visible brand replacement), I am changing to the 4.0 pump that was working well and see if it corrects and maintains the pressure.
 

franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
3,477
Reaction score
1,791
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
Thanks, I am using a 95 Explorer but this is useful info, where can I get diagrams like that? the EVTM?
I got them from my local library. Most libraries have this service. Just go in and get a library card, it's free. The card has a long number on it. Then get online on your libraries website, and click on chiltons online or whatever they have. They will ask you for that long number off your card, and then you are in.
 

Sponsored Ad


Sponsored Ad

Staff online

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Mudtruggy
May Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top