tuning question...

[jjmitch87]

ok guys i have a question. lets say i want to get a tune/tuning software/tuner (whatever) for future mods- pulley drop, headers downpipe, plugs, tstat, etc (as outlined in the safely modding thread). im a noob as far as tuning goes. heres the problem. my car(2001 gtp sedan) has one vin(obviously). previous owner told me the guy he bought the car from replaced the engine to one from a regal gs, and a reman trans from GM (the hd one- i can see the reman sticker on it). i have no idea if the pcm has been tuned or is stock gtp or gs one. can a stock pcm be tuned? would i need to buy a pcm and then tune and case learn(whatever a case learn is)? if i have to give a vin number would my cars vin still be good even though its a different motor? (read somewhere that the gs/ssei/gtp motors are the same). im a bit stumped and probably overthinking it. ive had the car to 110mph and previous owner said he had it over 125mph, what is the limiter set at stock for a gtp?

also, probably in the wrong section but id hate to make tons of forum threads: the guy told me my drivers side front tire has a flat spot. its barely noticeable when driving around town but going 70 on the highway its HORRIBLE. its worse under 70 and accelerating than coasting at 70. my stepfather (a senior master tech for ford, told me to overinflate the tire to 50psi and drive it a bit and it might pop the flat spot out. it hasnt yet and ive driven maybe 20miles since). the other thing is ive read the post about the hud photo cell having bad solder and gets dim, mine isnt really dim but what does happen sometimes is if im at a stop in drive, the hud will cycle mph from like 0 to 150 to 0 to 150 to 0 over and over until i move, but it doesnt happen all the time. i dont think resoldering the photo cell would fix that (assuming the photo cell is for brightness of the display itself).

any thoughts? i feel like i have a franken-gtp.

 

[Z34Phoenix]

If you get a DHP powertuner your vin won't matter. If someone is local with a tuner thy might be able to help you read your PCM and check if it is modded and verify the vin.

As for the HUD my guess would be a loose connector related to the speed input to the HUD.

And running the tire above psi isn't really a safe thing to do. Have you tried getting the tires rebalanced? Vibration at hwy speeds is normally just a balance issue. If the tire is ou of round chances are the belts have shifted or damaged. If that is the case get a new tire.

 

[jjmitch87]

ill try to see if theres anyone local to the boston area with a tuner.
as for the HUD ill pull it apart anc check connections when i get a day off from work.
and for the tire issue ill put it back down to normal psi tomorrow morning and see about getting 2 new tires for the front and use the passenger side as a full size spare if i can find a 17inch rim.
also need to buy a new RCA cable because my sub hits when it wants to and im leaning towards that being the issue since i just fixed all the wires and swapped the head unit.
thanks for the help!!

 

[dsmuts]

Swap the tIres to the back and see if it gets better

 

[Seachicken]

x2^^

tire out of balance? check to see if your missing weights.

 

[jjmitch87]

good idea. might do that tomorrow morning when i change the oil before work as the front will be jacked up anyways.

 

[jjmitch87]

a week late but i forgot about this thread. i swapped my tires front to rear/rear to front, the problem is 90% gone. when i took the tire off that i was told had a flat spot, upon personal inspection it does have a flat spot. on the rear tho its not bad at all. i was informed i have a friend with a firebird that has a tuner, so im gonna call him next week and see if he can check out my pcm. also happened to run into the guy who bought the car new, gave to his son, son hit a speedbump/pothole/something and ripped the oil pan off and continued to drive the car, killing the engine. he said they swapped the engine from a regal gs(50k miles on it i think he said) and a brand new not reman trans from GM (something about the pan got damaged as well and ran out of fluid). his son sold the car to my buddy and i bought it from him.. so now at least i have some history on the car.