87 Ranger 2.9L Issue

[Wrongway]

Replaced the TPS, Ignition Module, Cap, Rotor....

Still when accelerating from a stop, about 1/4 throttle, it starts to sputter and bog. Anything past 1/2 throttle it runs up fine.

So if your cruising down the road at 35 it sputters and pukes at a steady throttle, I have to continue to play with the peddle to keep it running correctly.

Driving me CRAZY not knowing what the problem is.

Anyone that might have an idea, I would appreciate the input.

Thanks in advance.

EDIT: This issue only happens when engine is at full running temp. About 5 min of driving till the issue begins.

Bill

 

[IMenriched]

Replaced the TPS, Ignition Module, Cap, Rotor....

Still when accelerating from a stop, about 1/4 throttle, it starts to sputter and bog. Anything past 1/2 throttle it runs up fine.

So if your cruising down the road at 35 it sputters and pukes at a steady throttle, I have to continue to play with the peddle to keep it running correctly.

Driving me CRAZY not knowing what the problem is.

Anyone that might have an idea, I would appreciate the input.

Thanks in advance.

Bill

Bill
best approach would be to get the codes 1st.
http://www.therangerstation.com/tech_library/OBD_I.html

and do general maintenance....tune up & etc... which you seem to have done

did your tune up include a fuel filter??

 

[treeguy]

I may be off . . . but have you cleaned the Mass Air Flow Sensor ? There is a thread on this . . .

 

[Wrongway]

I will check the mass air flow sensor tonight.

Reason I didn't check it was it runs fine when cold. Takes a good 5 min before it starts acting up.

 

[Wrongway]

Bill
best approach would be to get the codes 1st.
http://www.therangerstation.com/tech_library/OBD_I.html

and do general maintenance....tune up & etc... which you seem to have done

did your tune up include a fuel filter??

Prior installation yes. about 6 months ago. Reason I have not checked the fuel filter recent is due to this issue only happens when the vehicle has been running for 5 min.

 

[Psychopete]

I will check the mass air flow sensor tonight.

FWIW, your Ranger does not have a MAS, but it does use a MAP sensor.

+1 to pulling codes though. No check engine light to notify you if the computer sees a problem. Good starting point since it's free.

Pete

 

[BillRod]

I agree to pull the codes first.
Checker has the OBD1 readers for $23 or $24.
Makes diagnosing much simpler than with a meter.

I had a similar issue, but mine was trying to maintain 75 on the hiway.
I diagnosed it down to the O2 sensor.

But pull the codes first and let the truck tell you.

Bill

 

[Wrongway]

Thanks for the info. I will look into a OBD1 Reader.

 

[treeguy]

Doohhh . . . forgot that ! MAF sensors went in 1988+ rangers . . . sorry for the bad advice !!

 

[Wrongway]

Ok.. Warmed up engine to operating temp.

Ran code reader. KOEO test (engine off)

Code 23,34,10,32

Ran code reader. KOER test (engine running)

Code 23, 42, 32, 74

Code definition.

23 - TPS Signal out of range. New TPS installed just before test?????
32 - EGR Pressure Feedback Fault ???
34 - EGR Valve not opening properly.
42 - HEGO (HO2S) Sensor Signal high / sytem rich???
74 - Brake on/off switch fault, not actuated.

Ok, only thing I can see that would cause the system bogging when HOT during take off would be the HO2S Sensor.. Is this the O2 Sensor in the exhaust pipe before the cats?

If so, I replaced that sensor about 2 months ago. Is it possible that the CAT's are plugged or broken? causing the richness?

Thanks for all the help everyone.

 

[Wrongway]

Also, is there a certain way to install the TPS? other then just stickin it on and putting the bolts in?

 

[Wrongway]

I replaced my O2 Sensor, seems to have fixed the bogging..

Question is.. Why did the O2 Sensor go bad in 2 months? Wondering if the Cats are broken or plugged.

 

[Oleredranger]

I had the same problem with mine when it was new only had about 30-35000 miles on it.
Could have been a bad sensor, or did you add anything to the fuel? I was using Marvel oil in the gas, until I found out it contained silicone. Silicone will KILL an 02 sensor in a heartbeat. Stopped using Marvel, no more problem. My old truck is an 87 2.9L. Biggest problem now is leaking valve cover gaskets. Old engine and the reman both have this problem.

 

[Psychopete]

Also, is there a certain way to install the TPS? other then just stickin it on and putting the bolts in?

I would start by testing the wiring to the TPS sensor. Note that all of these test should be done by using the sensor ground, and NOT the battery or chasis ground. It's imperative to verify that there isn't a bad ground going to the sensor itself.

Check your TPS reference voltage against the ground to the TPS sensor, should be around 5 volts with the key On.

Check the base reading of the TPS sensor (the other wire that goes to the computer) and verify that it's around .9 volts.

With an analog volt meter, verify that the TPS sensor sweeps the needle smoothly from the base voltage to the reference voltage.

There's 3 wires, don't have a diagram for them, but with some poking around with a volt meter, it only takes a second to figure out which is what.

Pete