• 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.

Aggravating 2.9 issue.....putt putt puttering....

rusty ol ranger

2.9L Mafia-Don
Supporting Member
Joined
Sep 22, 2007
Messages
8,984
Reaction score
3,715
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
Ok now my truck runs great 90% of the time but has had this super annoying, seemingly random issue since i got it going and i cant figure it out....

When you first start it when the engine is cold....if you let it sit and idle for more then 30 seconds or so before you accelerate, or if you get into it a bit, it acts like its running out of fuel. Super boggy as soon as you get the clutch out, then its fine untill you shift to 2nd and same thing...

then the SOB runs fine untill....

You drive it more then about 20 miles or so, itll do this annoying misfireish thing when your on the throttle and bringing the clutch up from a stop then it chugs and putters and its fine untill you shift into 2nd then it does it again. You can also notice it if youre cruiseing at 55 and lay off the pedal and get back into it. Then its fine.

The only way ive found to keep it from doing this is to give it a quick stab of the go pedal to the floor while the clutch is down, then its fine when you take off (usually).

If its puttering i can also put it to the floor and it straightens up also.

It was really bad untill i did the idle adjustment thing now it does it less often. Bit more severe.

Ive replaced the MAP, TPS, CTS, AIT, O2, new plugs/wires yada yada.....

This is annoying as hell and i wanna get it figured out. Both the intank pump and rail pump are new, as is the injectors and tank.

I want to say its a fuel issue but it never misses a beat at high RPM...its just right off idle or right as you crack the throttle at speed.

It seems to be heat related...possibly a weird ignition module issue? (also pretty new).....

But it also does it cold. I have no idea.

Anyone else got an idea?
 


Paulos

Active Member
Joined
May 7, 2018
Messages
476
Reaction score
204
Points
43
Location
North Carolina
Vehicle Year
1987 STX
Make / Model
Ranger
Engine Type
2.9 V6
Transmission
Manual
2WD / 4WD
4WD
It doesn't sound like it's heat related if it does this when it's cold after only 30 seconds or so, or am I miss-reading what you stated?
Have you checked your coil for resistance?
What about the ignition module connector? I have found that 30+ year old connectors don't play well with some newer modules (thinner blades).
It sounds like it could be an intermittent connection issue in the ignition system. Have you tried swapping out the ignition module with a known good module?
Have you ever changed the pickup coil?
Do you have a spare ECM to swap out and test with?
 

Shran

Junk Collector
Forum Moderator
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
7,349
Reaction score
2,716
Points
113
Location
Rapid City SD
Engine Type
V8
Engine Size
5.0
Kinda feel like you need to verify voltage on the TPS throughout its range of movement.

Fuel pressure reading? Throwing any codes?

Huge vacuum leak somewhere?
 

rusty ol ranger

2.9L Mafia-Don
Supporting Member
Joined
Sep 22, 2007
Messages
8,984
Reaction score
3,715
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
It doesn't sound like it's heat related if it does this when it's cold after only 30 seconds or so, or am I miss-reading what you stated?
Have you checked your coil for resistance?
What about the ignition module connector? I have found that 30+ year old connectors don't play well with some newer modules (thinner blades).
It sounds like it could be an intermittent connection issue in the ignition system. Have you tried swapping out the ignition module with a known good module?
Have you ever changed the pickup coil?
Do you have a spare ECM to swap out and test with?
It does it cold like stated...but then it exhibits goofy symptoms after about 20 miles. For the most part in between it runs excellent.
Ignition module connector is good and tight, havent tried swapping modules yet...ive got a bunch around here. But that module is new(ish) but it is a cheapo...so maybe. Dist/pickup are new to.

I have 2 87 ECMs but currently running the 88 ECM @PetroleumJunkie412 gave me to do away with the EGR/knock bs.

Kinda feel like you need to verify voltage on the TPS throughout its range of movement.

Fuel pressure reading? Throwing any codes?

Huge vacuum leak somewhere?
I thought TPS to....i only have a digital DVOM but its a new TPS...no difference after swapping out the old one.

Fuel pressure is around 40 where it should be but i dont have a way to test it when its acting up.

Codes? I dont remember the numbers but all that was there was a speed sensor code and that stupid "didnt have it in neutral" code.

I have checked for vaccum leaks with ether to no avail. Dont hear any hissing. I pulled the TB off, cleaned it all up. No change.

Almost sounds like TFI

@RonD
Ive kinda thought that all along but i figured it would of left me sittin by now.
 

Shran

Junk Collector
Forum Moderator
Supporting Member
Article Contributor
V8 Engine Swap
Solid Axle Swap
Joined
Mar 4, 2008
Messages
7,349
Reaction score
2,716
Points
113
Location
Rapid City SD
Engine Type
V8
Engine Size
5.0
Well if the TPS is set wrong then it may have weird issues. It should read somewhere between .75 and 1v with the throttle closed and move smoothly up to about 5v at WOT. You can definitely check it with a DVOM, I never use my analog, just move the throttle slowly.

Lots of possibilities, I think the next step is to narrow it down to an intermittent electrical issue or air/fuel mixture issue.

My Explorer was doing something sort of like this but I think I have it narrowed down to a leaking injector. I will know for sure when I get them back. It ran fairly well above 1/2 throttle but idle to that point was not good.
 

rusty ol ranger

2.9L Mafia-Don
Supporting Member
Joined
Sep 22, 2007
Messages
8,984
Reaction score
3,715
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
Well if the TPS is set wrong then it may have weird issues. It should read somewhere between .75 and 1v with the throttle closed and move smoothly up to about 5v at WOT. You can definitely check it with a DVOM, I never use my analog, just move the throttle slowly.

Lots of possibilities, I think the next step is to narrow it down to an intermittent electrical issue or air/fuel mixture issue.

My Explorer was doing something sort of like this but I think I have it narrowed down to a leaking injector. I will know for sure when I get them back. It ran fairly well above 1/2 throttle but idle to that point was not good.
I pulled the plugs and they were all uniformly black. So i *doubt* its an injector. I hope...i dont wanna do that job again.

Ill double check the TPS voltage.
 

PetroleumJunkie412

2.9 Mafia
TRS 20th Anniversary
Joined
Oct 31, 2018
Messages
7,304
Reaction score
5,709
Points
113
Location
Dirtman's Basement
Vehicle Year
1988
Make / Model
Ranger
Engine Size
2.9l Trinity
Transmission
Manual
2WD / 4WD
4WD
My credo
Give 'yer balls a tug. Fight me.
Ive kinda thought that all along but i figured it would of left me sittin by now.
Maybe. One of the ones that went bad on me would just randomly cut spark then randomly start working again. Didn't matter if it was putting down a dirt road or doing 65 on the highway. Was weird, but was messed up TFI module
 

rusty ol ranger

2.9L Mafia-Don
Supporting Member
Joined
Sep 22, 2007
Messages
8,984
Reaction score
3,715
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
Maybe. One of the ones that went bad on me would just randomly cut spark then randomly start working again. Didn't matter if it was putting down a dirt road or doing 65 on the highway. Was weird, but was messed up TFI module
Its supposed to be warm this week once i get the fuel line on the 77 ill switch tfi's and try it.
 

Burnsy

Member
Joined
Aug 6, 2021
Messages
69
Reaction score
22
Points
8
Location
Hudson fl
Vehicle Year
2001
Make / Model
Ford ranger
Transmission
Automatic
It does it cold like stated...but then it exhibits goofy symptoms after about 20 miles. For the most part in between it runs excellent.
Ignition module connector is good and tight, havent tried swapping modules yet...ive got a bunch around here. But that module is new(ish) but it is a cheapo...so maybe. Dist/pickup are new to.

I have 2 87 ECMs but currently running the 88 ECM @PetroleumJunkie412 gave me to do away with the EGR/knock bs.


I thought TPS to....i only have a digital DVOM but its a new TPS...no difference after swapping out the old one.

Fuel pressure is around 40 where it should be but i dont have a way to test it when its acting up.

Codes? I dont remember the numbers but all that was there was a speed sensor code and that stupid "didnt have it in neutral" code.

I have checked for vaccum leaks with ether to no avail. Dont hear any hissing. I pulled the TB off, cleaned it all up. No change.


Ive kinda thought that all along but i figured it would of left me sittin by now.
Not sure if your vehicle has it but maybe output speed sensor that would bolt onto top rear of tranny, or vehicle speed sensor, bolts to top of differential, or neutral safety switch
 

Burnsy

Member
Joined
Aug 6, 2021
Messages
69
Reaction score
22
Points
8
Location
Hudson fl
Vehicle Year
2001
Make / Model
Ford ranger
Transmission
Automatic
Maybe reset idle to how it was and wait for the correct fix, your idle adjustment may not allow you to see if a correct fix is happening with a new fix attempt, if the idle is (now) incorrect.....
 

rusty ol ranger

2.9L Mafia-Don
Supporting Member
Joined
Sep 22, 2007
Messages
8,984
Reaction score
3,715
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
Not sure if your vehicle has it but maybe output speed sensor that would bolt onto top rear of tranny, or vehicle speed sensor, bolts to top of differential, or neutral safety switch
It does have a speed sensor but the gear in the trans that drives it is shot. I was under the assumption these older trucks (mines an87) used that mainly for the cruise control?
Maybe reset idle to how it was and wait for the correct fix, your idle adjustment may not allow you to see if a correct fix is happening with a new fix attempt, if the idle is (now) incorrect.....
The idle was way incorrect before, now its correct. It used to idle to low,
 

Paulos

Active Member
Joined
May 7, 2018
Messages
476
Reaction score
204
Points
43
Location
North Carolina
Vehicle Year
1987 STX
Make / Model
Ranger
Engine Type
2.9 V6
Transmission
Manual
2WD / 4WD
4WD
Hey Rusty, this page in the Tech Library says "The Vehicle Speed Sensor (VSS) supplies this signal to the components that require vehicle speed information including the speed control amplifier for cruise control equipped vehicles and computer. The computer uses the VSS signal for emissions control programs and speed limiters. The emissions programming can cause a manual transmission vehicle to stall out while decelerating if no VSS is used".
The VSS also plays a part in 4x4 automatic transfer case shifting, as it will only shift into 4 low when the vehicle is not moving.
 

rusty ol ranger

2.9L Mafia-Don
Supporting Member
Joined
Sep 22, 2007
Messages
8,984
Reaction score
3,715
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
Hey Rusty, this page in the Tech Library says "The Vehicle Speed Sensor (VSS) supplies this signal to the components that require vehicle speed information including the speed control amplifier for cruise control equipped vehicles and computer. The computer uses the VSS signal for emissions control programs and speed limiters. The emissions programming can cause a manual transmission vehicle to stall out while decelerating if no VSS is used".
The VSS also plays a part in 4x4 automatic transfer case shifting, as it will only shift into 4 low when the vehicle is not moving.
Hmm....so maybe this is related to not having a functioning speedo????

Ive never had it stall on deceleration
 

bobbywalter

TRS Technical Staff
V8 Engine Swap
TRS Technical Advisor
TRS Banner 2012-2015
TRS 20th Anniversary
TRS Event Participant
Joined
Aug 9, 2007
Messages
22,293
Reaction score
2,832
Points
113
Location
woodhaven mi
Vehicle Year
1988
Make / Model
FORD mostly
Engine Type
V8
Engine Size
BIGGER
Transmission
Automatic
2WD / 4WD
4WD
Total Lift
sawzall?
Tire Size
33-44
My credo
it is easier to fix and understand than "her"
351 4 bbl.

Or mega squirt.


Whatever is cheaper for those two options ...is the best option.
 

Sponsored Ad


Sponsored Ad

Top