Hesitation and riding rough around 60MPH

[Prime85]

I have a 97 GST

Recently i have started having two problems with my car. About a couple months ago i started to feel a little hesitation every few seconds after driving for about 20 minutes, (example:i would have my foot on the peddle at a steady speed and then every few seconds i start to feel the car hesitate)

I have changed the fuel filter about a month ago (did not help)
I have also tried using Lucus injector cleaner which did not help as well.


My second problem is a little worse. About a week ago my car started riding really rough when i get it up to around 60MPH.

I thought that i needed to get the tires balanced so i got them balanced and rotated and that did not solve the problem. These are new tires with no more then 3000 miles on them, they were inspected as well when it was brought in.

Thank you for your time and help.

 

[96' Eclipse GS]

Any CEL's on recently? Run a BLT & Vacuum Test, is where I would start....

 

[19Eclipse90]

Are you using a 1G CAS? Please fill out your vehicle profile.

 

[biowolf]

How old are your axles, shocks and struts?

 

[Prime85]

So there are no CEL's showing on the car


my car has a Evo III motor with G1 CAS

also the axles shocks and struts are all stock that came with the car.

Other then the motor and the CAS everything else is stock.

 

[Bflood]

Hey, it sounds like a fuel problem, is that a stock fuel pump on your car? if so you might want to change it to a walbro or whatever fuel pump thats new, or maybe your injectors arnt working right, Its somthing with your fuel I think.

 

[Prime85]

i guess i can try a new fuel pump, Should i get the high pressure walbro 255LPH? or the normal one?

 

[19Eclipse90]

You say you feel the hesitation every few seconds -- does it stop by itself or do you do something to make it go away, i.e., pull your foot off the gas, put the car in neutral, etc.?

 

[Prime85]

i dont do anything, What happens is i feel it lose power for a second then it fine for a few more seconds then it does it again.

This doesn't start until i have been driving awhile (around 20 Min)

My other issue which i think is a completely different problem happens every time my speed gets around 60MPH

 

[96' Eclipse GS]

Have you done any tests yet?

 

[forcefed_90tsi]

Don't go throwing parts at it just yet. You want to run all your basic tests first. Get the car up temp then run a fuel pressure test take for a spin and check it again. Do it atleast 3 times and see what readings you get. Then check spark etc. I've read in a couple posts that the viscous is known to cause vibration at highway speeds and also kind of a whining noise

 

[AK Maniak]

Start off with the most simple things like your spark plugs... My last GSX would hesitate under throttle intermittently and it ended up that the spark plugs weren't gapped properly

 

[forcefed_90tsi]

Forgive me for that. Its not a viscous. I meant lobro. Here is a link to the post. You may have the same symptoms. http://www.dsmtuners.com/forums/maintenance-repairs/428725-drive-train-problems.html

 

[Prime85]

the problem ended up being a stuck Caliper. Fixed both issues! Thanks for everyones help in this.