1991 Low on power

[elanman]

I just got my mother 1991 xlt 4x4 with the 2.9 she has always took good care of it other than rust issues, my problem is very low on power also it does have aoutomatic if that matters when we put this thing to the floor it is lucky to get 50 miles an hour it backfires spits and sputers it seems, but it starts and run at idle just fine. What we have done so far fuel filter full tune up and still runs the same ,also we thought mite be convter plug and we gutted that as well did nothing for it. I know it must be a sensor or somthing but we have no check engine light on ? well thanks in advance for the help.

 

[jhammel85]

How old is the o2 sensor? I'd have to wonder about it, especially if it bogs down at all. Before replacing, I'd check the connector and its wiring too.

However, My 1st thought is timing. Remove the spout plug and check the timing. Should be 12* BTDC

 

[elanman]

The o2 I would say is the orginal one, will check the wires to it, The spout plug I'm sure you are talking about is that little plastic plup you remove. will try and check that as well. could it maybe be the module ? just a thought.

 

[Cooter199]

i would check the automatic advance timing if it has one. cause my friends ranger had a vacum leak in the advance timing but then again i dont know if the newer trucks have them or not.

 

[robertc1024]

If you replace any sensors, disconnect the battery for 1/2 hour or so and drive it around so the computer can re-learn the correct tune.

 

[elanman]

Checked the wires and stuff to the o2 all seemed good, did not check timing with light but we advanced it retarted it still makes no difference.
Is there any way we can self test some of these sensors ? or what type of code reader would we need to do a truck this old ?

 

[jhammel85]

Here you go. Try this.

http://fordfuelinjection.com/?p=13