93 Ranger 4.0 issues

[rkbonds1]

Right now there are 3 main issues I need to figure out. 1. The truck is only getting 6 mpg. 2. It has a small vibration when you first start to take off from a stop lasts until you reach 15 mph. 3. When you turn the ignition switch off the truck keeps running for 20-30 seconds (it's not dieseling it just continues to run like you haven't cut the switch off)?

Now the truck is a 93 super cab Ranger with 7 inches of lift and 35 inch tires 4.0 automatic No check engine light is on truck seems to run perfect other than these issues. Can someone tell me where to look to try and find the source of these problems? I bought the truck for work but, with it using that much gas I can't even afford to drive it.

 

[rkbonds1]

No ideas?..... Guess everyone is as stumped as me....

 

[starshooter10]

I would start by pulling the plugs... its stupid easy to do on this truck/engine combo

 

[hondaxr650]

I have to ask. Has the speedo been corrected for the 35 inch tires? If not, your mileage figures aren't even close to accurate.

 

[rkbonds1]

I did a lot of different things and have the mpg's around 10-12 currently which is a big improvement.

1. pulled plugs and cleaned them

2. cleaned MAF and TB and IAC

3. changed o2 sensors

4. Made sure all air pressure was at correct psi.

5. found out the gear ratio is what I would want if I were running 33's or smaller

My speedo has been re-calibrated and shows correct. The biggest problem I've ran into with this truck is buying someone else's play toy and trying to use it as a daily driver. I also recently discovered the on trail repair of the rear brakes was not splicing the rear brake hose back together it was to pinch off the rear brake hose all together so it had no rear brakes. Then I discovered half of the brake parts in the left rear wheel were missing, wheel cylinder leaking and just messed up big time. I have ordered the parts to get it all put back together correctly and they have all finally come in. So tomorrow I will be putting a new rear brake system on the truck and hopefully getting rear brakes..... This has been more of a headache than I thought I was getting into....I guess people will tell you anything to sell you their junk.

 

[swtjames23]

First off, I feel your pain on the whole buying other people's problems thing. Best thing you can do is just rebuild from the ground up and then you'll know what you're working with.

As far as the problems you're having:

1. Fuel mileage will likely improve significantly if you re-gear to 4.56s. Also, change the fuel filter (easy but be sure you relieve the pressure in the lines first) and the PCV on the driver side valve cover. These will both improve mileage. Lastly, malfunction brakes (i.e. siezed calipers) can cause excessive drag which will kill your mileage.

2. The vibration could be the driveshaft. If the angle isn't corrected, large amounts of lift cause the angle to be too much for the driveshaft to handle. Your driveshaft is two piece, try lowering the carrier bearing.. or even better, swap in a one piece from a '98+ supercab.

3. This one is weird... It sounds to me like the ignition switch isn't working right so the only thing that shuts the engine off is running itself out of fuel. I have no idea how to fix it, good luck.

Hope this helps.

 

[rkbonds1]

I'm pretty sure the vibration is the driveshaft, I will probably try to lower the carrier bearing at some point in the near future. The ignition switch is bad and for now it doesn't bother me to much but, I will be changing it out sometime in the near future. I don't think I'll re gear I'll just put on smaller tires (33's) that way it will make using it as a work truck a little easier.

 

[Tdog57]

93 ranger 4.0 issues

I thought I had a bad ignition switch when my Bronco would occasionally keep on running after I shut the key off. It turned out to be a short in the wiring under the dash. I'm not good at wiring at all, so I had to take it to an independant shop, but they found it and fixed it.

 

[rkbonds1]

Ok, I know I haven't posted on this topic in a while but, I got around to changing out the electrical part of the ignition switch today and the truck is still continuing to run after I turn the switch off. I did do a little checking things out and discovered that if you only turn the switch on (turn on all dash lights) then turn the switch off the dash lights stay lit up for as long as the truck would be running then slowly fade out. What would be holding power that long and what else should I be looking at to resolve this problem?

 

[rkbonds1]

No ideas????

 

[bcammons]

Not sure about the other problems but as for the vibration from a start another issue could be that if you are running knobby mud tires then that could be it (kinda depends on how they are wearing)....... had lots of mud tires and had this exact thing youre describing.