Runs Great and then Runs good

[FordRanger1991]

Hey so i thought i would throw a question out for fun to see if anyone wanted to put in some information. I have a 2.9 engine that seems to run great sometimes and then just decent at other times. I have 4.56 gears and only 31s right now so my truck is actually pretty quick. However, sometimes i feel like i could take her to the drag strip and other times i feel like it is not that strong. The engine always seems to idle and sound the same. Just wondering if you guys can think of something easy to make it so she runs super strong all the time. lol hope someone out there knows what i am talking about with their experiences.

The engine was rebuilt about 10k ago and have new wires and plugs and all that kind of stuff so everything seems to be working properly.

Thanks for your time!

 

[RustedRanger]

My 87 is like that....I've done just about everything I can do keeping in mind it's a $500 truck. Sometimes it runs nearly perfect and other times it idles rough or when I go smoothly through the gears I can feel it jerk around a bit. A couple times I had a friend put his diagnostic computer on it and he found everything to be working alright (aside from the problems he found that I fixed)....it still runs the same,really good and not so good at times.

 

[FordRanger1991]

With my truck it is just weird because it always idles perfect. It just feels like it has more power sometimes and less power other times. I have ran a code scanner for KOER and KOEO but nothing has come up... I guess it will just always be like that. Weird though because i feel like i should be able to get it to run strong all the time...
thanks for the comment though RustedRanger.

 

[freedom5]

Hey so i thought i would throw a question out for fun to see if anyone wanted to put in some information. I have a 2.9 engine that seems to run great sometimes and then just decent at other times. I have 4.56 gears and only 31s right now so my truck is actually pretty quick. However, sometimes i feel like i could take her to the drag strip and other times i feel like it is not that strong. The engine always seems to idle and sound the same. Just wondering if you guys can think of something easy to make it so she runs super strong all the time. lol hope someone out there knows what i am talking about with their experiences.

The engine was rebuilt about 10k ago and have new wires and plugs and all that kind of stuff so everything seems to be working properly.

Thanks for your time!

I have an '87 2.9L that had similar problems. I found if I add a can of fuel injector cleaner every few fill ups it has made a big difference. The older engines weren't made to run on fuel with ethanol added and it's almost impossible to find any fuel without it. Give the injector cleaner a try - it certainly wont hurt.

freedom5

 

[RustedRanger]

I use Lucas fuel injection cleaner when I can,it does help and it helps the miles per gallon also,last I checked I was getting 22+ mpg (with Lucas) and the thing has 170,000+ now. On the highway mine has times it seems like it running perfect....other times I can feel it running worse. Also...when the weather changes or I change a part I unhook the battery to reset the computer and that helps some. Keep in mind a diagnostic scanner is different then a code scanner,my friend "looked" at how all the sensors was working and they all seemed to be working fine. I kinda wonder if the age has something to do with this kinda problem....wiring deteriorating.

 

[86Ranger Nathan]

My 1986 2.9L V6 does the same thing. Haven't found the problem but I will try some of the things listed in this thread, and if I find some miracle worker, I'll let you know.
My computer gives me codes (31 & 32) saying that my EGR valve is not working properly. I had thought that might be part of the problem, but I guess not. I'm glad to know that I'm not the only one having this problem though.

 

[FordRanger1991]

So i thought for fun i would check my spark plugs and i found one that was soaked in gas and very dirty. I changed my plugs and ran some lucas injector clearer through it and now everything seems to be running strong and i have all the power that i think she could put out.
However, sometimes when i am in a drive through or am letting my truck idle for some period of time it likes to jump back and forth from like 400 to 900 rpm. Any quick ideas? This idle problem happens when it is fully warm and will stop the second i apply gas.
Thanks for all your time!!

 

[FordRanger1991]

My 1986 2.9L V6 does the same thing. Haven't found the problem but I will try some of the things listed in this thread, and if I find some miracle worker, I'll let you know.
My computer gives me codes (31 & 32) saying that my EGR valve is not working properly. I had thought that might be part of the problem, but I guess not. I'm glad to know that I'm not the only one having this problem though.

Ya 91s dont even have EGR valves but thanks for the thought. Ya my bros ranger seemed to have the random power but some new spark plugs and injector cleaner seemed to help at least with the power issue now i need to figure out my idle issue that i talked about in my last post. It should be a simple fix i am thinking though.

 

[86Ranger Nathan]

O2 Sensor

I have changed my Oxygen Sensor and I now have all the power, all the time!
Not sure if i have mentioned it in this thread, but I have had idle problems with mine also, and the new Oxygen Sensor has fixed that problem, so right now I am a very happy camper! Hope you can get yours fixed soon too!

 

[FordRanger1991]

I have changed my Oxygen Sensor and I now have all the power, all the time!
Not sure if i have mentioned it in this thread, but I have had idle problems with mine also, and the new Oxygen Sensor has fixed that problem, so right now I am a very happy camper! Hope you can get yours fixed soon too!

ya I actually changed mine like 500 miles ago so I dont think that is the issue with the my idle problem. But i dont think i will worry about it too much because the truck seems to have all the power possible and it only idles weird sometimes. but ya a little Lucas and some plugs seem to be working good! thanks for all your comments!