iv had this fault with my car since i got it a year ago, feels like my drive train is fitted to the car with rubber bands, if you floor it, it will rock back and forth on the power almost like your coming on and off the gas really fast, or the rear axle is moving back and forth

things iv changed.....
plugs
leads
cap
rotor
tps
map sensor
o2 sensor

also changed
tranny mount (e/s poly ones)
t/a mount also poly

i got the rear end up in the air and checked all the bushings with a big lever bar and they all seem ok

at around 70 mph if i come off the power i notice the gear lever move forward about 2" and if i get back on it it will do the the reverse.
i have a bit of a non smooth idle like its missing a few beats but random ie not one cylinder (could this be a weak spark?)
im NOT getting any codes, just 3x code 12 then 3x code 12.
running out of ideas and seriously considering geting rid or pulling out the v6 and going for an early set up 350 with carb

i think my shocks and struts need replacing but can this be the problem???

please help guys

Nick (uk)

 

You checked your motor mounts...notice any clunking? My panhard loosened up and it made the backend feel loose, but this is not what you are describing at all. The back and forth action of the tranny would make me think the motor is shifting? Does it go up and down at all or just back and forth... any side to side? That sounded bad, but you get my drift!

Shocks and struts i don't think woukd effect the motor tranny assembly movement... Are your Lower control arms both rock solid...make sure there are no bolts missing!

You got me stumped for an easy answer!

 

cheers for the reply, when i say about the motor and tranny moving i mean it feels like its moving more than actually moving so to speak, iv just realised that iv never changed the fuel filter on this car, i meant to but they sent me the wrong one and i never got round to sorting it out, im really thinking this could be my problem as it is worse in the low gears and gets better in the high gears.

i will do this asap then get back to you with the results if this dont cure it then im just gona take it to the local tuners, they are fuel injection peeps and they have a nice rolling road so i will get them to thrash it a bit and tell me how much more horse power i get when they fix it. its all a learning curve as my mate keeps telling me lol.

Nick

 

I have had my bird since 89 and I still am on a learning curve!

The fuel filter if blocked up will definately make the car stutter and stumble. Joe just replaced the fule filter on his 97 SS...it was acting like it had bad gas, but it was a clogged fuel filter! With the new one....the car behaves normal once again!

Good luck!

 

Check your mounts... both engine, the tranny, and the tq arm mount.

 

doward, hi . i dont know if you remember a while back i replaced all the tranny mounts ie the main one, the 2 isolators and the t/a mount with energy suspension poly ones.
iv checked all the rubbers on the rear end and they are all ok i think.

iv checked the engine mounts by putting it in 1st with the hand brake on and let the clutch up and down and the engine didnt move much.

today i had a look for vacumeleaks and i traced a vac line along the drivers side inner wing and it went under the water bottle then dissapeared in to the wing. then found it came out again so i had a fumble and i noticed the 2 pipes went in to a T piece and the 3rd conector on it was open and sucking like a harleys air filter lol. could this be the fault iv been searching for. i pluged it up and sisnt notice much but im told it takes a few days for the ecm to adjust it self what do you think?


i have noticed though that when my blowers are on and i floor it it no longer stops the air from coming out my vents like it was before and the funny thing is i just thought this must have been normal so if this isnt my fault at least i can have the blowers on full power while flooring it
i got air con issues but i wont bore you with that il post it up on the right board.


Nick

 

There are a few vacuum lines that are for the blower vents that will cause the vents to not blow properly. Can also effect performance depending on which lines they are!

For a more effective ECM relearn you can disconnect the batterery. Wipes memory. Then let the computer relearn with a fresh start!

 

You don't have to disconnect the battery to do this, in case you have an aftermarket stereo or something with 18 presets... You have to find the frame-mounted fuses (yes, they are mounted to the frame rails) next to the evap can. The one with the red and orange lines is the one you are looking for. Pull the fuse holder out of the mount and pull the fuse out for, say, 15 sec. Then put it back in and go for a drive to let the computer go through the idle relearn process.

In the engine compartment, there are supposed to be two black vacuum lines for the HVAC, both coming out of the wiring harness on the PS side of the engine, at the heater box. One is for the IN side of the HVAC controls, and the other is for the heater control valve on the PS side of the engine. Chances are the one that you describe as sucking air is the line for the heater control IN port, and is supposed to have a third line on it, leading to either the vacuum tank or cruise control modulator, if you have or had one in the past. If you remove the check valve (the T-thing) and properly splice the vac lines together, you won't have any more problems with the HVAC (or less probs).