3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Hey Guys, New the this site, And Found a bunch of great info for my new Ranger i bought last month. One Problem is still getting to me and i have been searching for the last week with no real direction to go.

My 3.0 V6 Sputters, Bucks/hiccups, when Cruising at around 40-45 mph. Right Before it switches in into a higher gear. Happens each time right before the higher gear kicks in through out all speeds as well. I feels like the engine stops receiving fuel for a split secound, when you just hold the gas pedal at a constant light pressure. I Thought it was just me being picky until my wife even said "What's with the truck sputtering like that?"

Under Full Acceleration there is no sputtering or hesitation at all, feels good very smooth. Also Idle is consistent and smooth.

I Recently Replace the Cam Sync and Cam Sensor, Plugs and Wires, Air Filter, Did a Seafoam Treatment through the brake booster line and fuel tank.

Any ideas on what could be causing the problem?

Thanks!

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Well this weekend I have been really trying to pin point the problem. Torque converter chatter sounds errr feels more like the issue. Did a bunch of research on that and i believe this is the problem with my truck.
Not Sure on how long ago Transmission has been serviced. Bought from a dealership last month. Truck only has 80,000 miles on it
I pulled the Auto Tranny Fluid Dip Stick and the fluid was clear and redish. Is there a lube that fixes the Chatter or any way to be sure of this? Do i need to bring it to the shop for a transmission job?

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

I was going to mention the TC, but it also sounds like it could be an issue with the fuel pump.

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

We'll After 3 weeks of tearing through the engine bay and transmission, replacing every sensor, spark plug, air filter, hoses Fuel Filter, cleaning everything MAF, IAC, throttle body, Transmission service, flush with new additives for TC Shudder and everything i can remember i did to fix this problem guess what......

It was a F****** Vacuum Line. Could not for the life of me believe it. I was getting ready to test the fuel system and pull that all apart when i noticed on the underside of the intake tube there was a big open hole. I looked around from this angle that is almost impossible to see at the found a disconnected vacuum line. WOW! plug it back in and did a test drive. Truck is back to normal! Finally!

Everybody Thank you for helping me to figure out this problem. I was almost at the point of getting rid of it because of the annoyance of this. Well i guess at the end of all this and a upside. I know that engine and transmission like the back of my hand and the truck received one hell of a tune up and engine service!

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Dovegabanna,
Are you saying that the vacuum hose that had come loose was in the air inlet tube that connects the air filter to the throttle body? My nephew's wife's car seems to have the same symptoms you described - pretty noticeable shudder/bucking under very light acceleration at highway speeds (light enough to cause acceleration, but NOT shift the transmission down a gear), but no problems under full throttle or at idle. Does my description sound like what you were experiencing?

David

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Shadetreemech,
Yes that sounds like exactly like the problem i did have. The hose that came lose was out side the air inlet tube. Basically when you open up the hood and your looking down,middle of the engine, you will see the radiator then the air inlet tube. The vacuum hose was on the backish side just out of sight, right in the middle of the tube.

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Thanks, Dovegabanna. I passed that on to my brother and he's checking the truck as I type. I found several others in the Ranger forum who seem to be describing the same problem, so I've been pointing them at this thread...I'm really glad you found the cause was a vacuum line. I was thinking torque converter (specifically, the lockup function) as you were. It could be that the symptom is caused by a locking/unlocking for the TC, but that the cause is actually the vacuum leak. Thanks again for posting your findings!
David

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Hey no problem, i am glad to help and contribute as much as possible. The reason i knew my problem was not the TC, was that i went up to my dads for a little surf trip and drove with him in his 96 F-150. Every few minutes around 45 mph to 55mph it would feel and sound like we just went over train tracks!. I knew then that was not my problem! lol

Re: 3.0 Auto Hesitation, Sputtering, Bucking Missing When Cruising?
 

Well at least she is all clean and new now, Thank you I am having the same problem.