WAGE_SLAVE

I have a 402ci, small FMS cam with Cartek Stage 3 heads upgraded to PP gold valve springs. Over the past few days, the car has been feeling like it is “dragging” when starting to accelerate almost like it is missing or something. You can here it “gurgle” thru the exhaust also until you go wide open with it. And now the idle is out of wack, it either idles too high in N or P or too low when stopped in 1st gear. Does this sound like something else, or a valve spring. Could I have a problem with my exhaust? I mean I drove it today and it pulls like a ****, just at lower speeds I get the dragging feeling. No SES codes either. I would think that if something broke or it is really missing it would throw a code or two. And I used quality parts and a reputable builder. Total miles are about 1,200 give or take. Is the motor still breaking in and this is just the way it is? Car feels completely different than it did 2 weeks ago with half miles on it.

strokedls1

iTrader: (1)

I had one go and didn't really notice a huge difference. I had rev springs and lost the outer on an exhaust valve but the inner held up. My idle was off and wot throttle had a lot of rich black smoke that tipped me off. After I changed the springs out the car felt great. Pull the valve covers and check out the plugs. I turned off the misfire table so it never coded out on ses. Your tuner may have done the same.

God Forgives I Dont

You should double check that your MAP sensor is still connected good behind the intake. At one time my car was doing similar things as yours and then eventually started messing up the shifts of the tranny too. Turned out after a lot of poking and proding around my motor I found that the vacum hose that connected to the sernsor at the very far side of the intake was about have way disconnected and thats why there wasn't a code triggered. Anyway best of luck, hope its not bad!

99SeanWS6

iTrader: (8)

i've been having the exact same problem. Also I have had a slight vaccum leak since i went with my vaccum modulated tranny. thanks for the help God ForgivesI Don't I'll have to check it out in the morning. i've been having on going problems with my car and it does turn out to be a valve spring i tihnk ill be geting rid of the car

General Jack

iTrader: (4)

I had a spring break on my car and it was basically undrivable. All I could do was limp it off the highway and pull over to wait for a tow. It wouldn't rev past 1800, there was a very audible metal on metal pinging, bad news all the way around. Based on my experience, you don't have a broken spring.

Hunter

I broke a spring Friday. Motor basically died the retainer fell off and the valve dropped into the piston and now I have my motor laying on the shop floor. Doesnt sound to me like you have a broken spring

Another_User

It sounds like something is wrong. It could be in the tune. Try and pull some codes, even if the check engine light is off. If I had a dollar for every reputable shop that F-ed up somebodies car I could open up my own shop and F up people's cars myself!

99SeanWS6

iTrader: (8)

same thing happened to me back in august. this time it turned out to be a crank sensor.