Does anybody know if there is a trottle body spacer for the tbi for the 91 dakotas? Im avering 11mpg highway with LT235/65/15 tires all the way around. I have switched to sythenic blend oil in the engine with no im provement. I have no fault codes and the O2 sensor was replaced last year. Im thinking about replacing the MAP sensor and the EGR valve as a what could it hurt solution. Anybody got any other ideas?

 

They have throttle body spacers for our trucks but they work best as a paper weight. They don't improve anything. The EGR valve's for our trucks cost between $80 and $100 and won't improve your gas milage much. My truck has pulled the EGR code since I got it and it gets decent gas milage considering I have a very heavy foot (14-18 mpg). You could try the MAP sensor but if your truck is running fine it's probably doing its job. You should try replacing the coil, distributor, plugs and wires if youo haven't already.

 

I might try the platinum 2 plugs. I have NGK variety in it now and I replace the wires, plugs, cap and rotor but have nope replaced the coil or distributor has a whol yet. Ive been using a WIX air filter and I might try preplacing the fuel filter. Just to see what happens, might take tinier steps than first thought.

 

Multiple electrode plugs don't do anything special for our motors either for what they cost. A whole lot of people on this forum like Autolite 3923 plugs (just do a thread search on those and you'll see what I mean). They are one step cooler that the OE plugs and some people have said they help with power gains, and others have said they help with fuel economy and cause they're cooler they can help stop any pinging if your engine does at all. And they are a whole heck of a lot cheaper than platinum multiple electrode plugs. I have them in my truck and I like them.

 

Does it matter if the engine is magnum or not? My engine is a nonmagnum 318 with the trottle body injector. I read somewhere some guy quoted that the TBI on the 318 is like pissing in the wind.

 

I'm not sure about that, hopefully someone else with a non magnum engine can answer that for you.

 

I found out something interesting today. I went to replace the NGK v groove plugs with your suggestion and found that one of the plug wires was shot to hell that plug wasn't getting and juice and wasn't firing (went and go new wires). When I pulled the plug it was dark and the rest of the plugs were nice and tan. Could this have been causing my low milage? I thought it was funny. The fuel filter they gave me at the store is the wrong style the one that is on my truck is like this -{===}- and the one they gave me is like this =[=====] so i guess ill be waiting to replace that until tomarrow i hope this helps my milage... Thanks for the info as well..

 

That could definatly have been causing your poor milage problems. I'm surprised that cylinder didn't hyrdolock due to the unburned fuel. I've seen it happen before in a chevy motor.

 

Im surprised that it even started in -20 degree weather we had here a few days ago. I believe i am very fortuniate that that didnt happen. I also put some sea foam in the tank and checked for error codes again and just got 55 end of errors.

 

Yeah, thats strange that it didn't give you a misfire code. It's probably not neccessary but you should leave your computer unplugged overnight to completely reset it. When it resets it has to get input from all the sensors and then re-compute what to do with the info. It will run rough for a few minutes but it should run better once it gets the info it needs.