2.9l problem. possibly fuel pump?

[jvs8864]

hey everyone, i know how knowledgeble you guys are so here is my problem:

i have an '86 ranger 2x4 2.9l. it has a 5 spd tranny.

usually in 2nd or 3rd gear, when i accelerate about 25% throttle, it starts bucking and jerking, and doesnt really get any smoother until i let off the throttle
a lot of my freinds think its the fuel pump
any one else experience it? lemme know if u guys have any questions to help figure this out, cuz i need to get this fixed so i dont get stranded somewhere
thanks alot!!
-James

 

[almostclueless]

Does it accelerate better with more throttle?


I wouldn't be surprised if it was more likely a TPS or MAP sensor, or the TFI module and wiring.


There is TFI diagnostic info in the tech library here.

 

[poweranger84]

mine does the same thing, its not the MAP sensor...already tryed that. i think its the TPS. didnt do it all that often, then the FPR went out, now it does it alot more

 

[IMenriched]

hey everyone, i know how knowledgeble you guys are so here is my problem:

i have an '86 ranger 2x4 2.9l. it has a 5 spd tranny.

usually in 2nd or 3rd gear, when i accelerate about 25% throttle, it starts bucking and jerking, and doesnt really get any smoother until i let off the throttle
a lot of my freinds think its the fuel pump
any one else experience it? lemme know if u guys have any questions to help figure this out, cuz i need to get this fixed so i dont get stranded somewhere
thanks alot!!
-James

agreed with other with those things mentioned.

Does it matter whether it is up to full operating temp or just after cold start up?? (rephrased)...does it do it all the time reguardless of how long it been running?

or~ only just after start up before it gets engine temp up?
or~...only after it is up to operating temp??

 

[terminater221]

I have a very similar problem with mine. Its also an 86 with a 2.9L but its a 4x4. It starts up rough and you constantly have to work the pedal to keep it running. It wont idle until it warms up after working the pedal for a few minutes. If you let off the pedal before its warmed up it dies. I took the gas tank off and tested the lift pump that's inside the gas tank. The lift pump worked but I drained the gas and put fresh gas in. That seemed to help a little bit. I would definitely test the lift pump before you spend a lot of money on replacing the main fuel pump. Its fairly easy to get the tank off. There is only 4 bolts 2 hoses 1 electrical plug and the sensor for the gas gauge oh and also the filling hose which just has a hose clamp. The link below is to a diagram on how to test the lift pump. There is multiple different ways to try cause I couldn't remember exactly which one it is. The circle with the dots in the diagram, is the electrical socket on top of the fuel tank.

http://www.freewebs.com/terminater221/lift%20pump%20diagram.bmp

 

[87 ranger]

o2 sensor bro... 02sensor every 50k

hey everyone, i know how knowledgeble you guys are so here is my problem:

i have an '86 ranger 2x4 2.9l. it has a 5 spd tranny.

usually in 2nd or 3rd gear, when i accelerate about 25% throttle, it starts bucking and jerking, and doesnt really get any smoother until i let off the throttle
a lot of my freinds think its the fuel pump
any one else experience it? lemme know if u guys have any questions to help figure this out, cuz i need to get this fixed so i dont get stranded somewhere
thanks alot!!
-James

 

[87 ranger]

these dogs eat o2 sensors constantly so shop the best price and buy one for the glove box. this is going to make a lot of 86,87 owners very happy...

 

[jvs8864]

it does it regardless of operating temp.
i always let my truck warm up though cuz its better for the engine and a cold engine requires 10x the amount of gas to get a vehicle moving then a warmed up one.
i just added this:
http://www.restoreusa.com/

didnt really help the bucking, but helped idle and i get slightly better mileage
ill probly drop the tank and see what the deal is with the pump, before the damn thing leaves me stranded
thanks everyone. appreiciate it

 

[IMenriched]

it does it regardless of operating temp.
i always let my truck warm up though cuz its better for the engine and a cold engine requires 10x the amount of gas to get a vehicle moving then a warmed up one.
i just added this:
http://www.restoreusa.com/

didnt really help the bucking, but helped idle and i get slightly better mileage
ill probly drop the tank and see what the deal is with the pump, before the damn thing leaves me stranded
thanks everyone. appreiciate it

James
the can of miricle goop isn't really going to benifit much of anything but someone elses pocket book.

when was last time you had the fuel filter changed?

have you checked both battery cables...they can corrode from the inside out, leaving you with minimal connection.

have you gotten the codes yet? proceedure for doing so in the Tech Library here at TRS http://www.therangerstation.com/tech_library/OBD_I.html

these codes help determine if it is O2 or HEGO sensor or the TPS (Throttle Position Senesor), both can offer these symtoms. but ...if it does it regardless of cold or warm engine temp, might think about either the TPS or FPR (fuel pressure regulator)

hope that helps

 

[jvs8864]

James
the can of miricle goop isn't really going to benifit much of anything but someone elses pocket book.

when was last time you had the fuel filter changed?

have you checked both battery cables...they can corrode from the inside out, leaving you with minimal connection.

have you gotten the codes yet? proceedure for doing so in the Tech Library here at TRS http://www.therangerstation.com/tech_library/OBD_I.html

these codes help determine if it is O2 or HEGO sensor or the TPS (Throttle Position Senesor), both can offer these symtoms. but ...if it does it regardless of cold or warm engine temp, might think about either the TPS or FPR (fuel pressure regulator)

hope that helps

yea bro that helps alot
im gunna see if i can get around to checking the codes today
thanks everyone