1 month left til tune, still problems

[ZigsGSX97]

ok....so I've had this vibration problem with my engine ever since I got the car 3 years ago. Whenever I rev it up between 2500-3000, my transfer case VIBRATES!!! horribly. Now I've replaced the transfer case fluid and that didn't seem to do it. I have also talked to transfer case experts and they said if it's making the vibration when in neutral, then it's not the transfer case! So next i moved onto motor mounts and found that 2 of them were bad. I replaced them, but still the nasty horrible vibration. Then I checked my balance shaft....no play and the belt has just been replaced. I'm running out of ideas. I have to get my car dynoed and tuned in less than a month and i was hoping to get rid of this damn vibration noise.
Also......my timing belt jumped a tooth and the plastic casings that surround the timing belt were broken beyond belief. I replaced the timing belt and it's running like crap now. It idles very poorly. Do I need to break it in and drive for a while or what? And when i go to boost, the turbo spools, but no go. Is this because i have 550s and no tune for my safc 2? A lot of questions....hopefully you guys know some of these things

 

[heppm01]

You have at least two separate issues.

If your car has been vibrating since before the t-belt problem, then either your balance shafts have been out of sync for that long or you have some mechanical vibration. The mechanic is correct that your transfer case won't cause problems in neutral, *however*, it may be that your downpipe is rubbing against your t-case, and as you rev it you can feel a vibration from that area. Either a 3" DP, or bad motor mounts can cause that sort of thing.

You bigger problem is that whoever redid your t-belt screwed up the job. No, it doesn't have to "break in" - in fact, that would likely just make it worse. Your cams and crank are likely out of sync, and the job will need to be redone.

The fact that your plastic covers were shattered makes me wonder if your belf skipped more than one tooth - that sounds like a pretty catastrophic skip. It may be that you had piston/valve contact, and have one or more bent valves.

And yes, running 550s with flat AFC settings will be very rich, and cause poor performance too.

Take things one at a time, and you'll get it straightened out.

Matt

 

[wt71gas]

If the turbo is spooling up and car is making no power there is definately a timing belt issue. Some of the valves must be slightly bent or open when they should not be

 

[ZigsGSX97]

ok, so i talked to my mechanic and he said he checked AND double checked the timing belt when he put it on. And he said the valves are probably ok. I'm still researching this and the vibration....it's possible it can be the exhaust though

 

[Maglin]

Chances are your balance shafts are not in time. You said it had a new belt on their. Well the rear balance shaft can be 180* out. that is the reason why you have to pull the plug on the back of the motor and ensure the weight is in the right spot when the oil pump gear's marker is pointing at the alignment mark. I'm sure who ever did the balance shafts before might have missed that.

Had a buddy with 272's and his car has a lot of vibration. I have poly mounts and no balance shafts and his car vibrated more than mine by a good amount. Told him to check them and sure enough he had the rear balance shaft 180* out. He fixed it and his car ran so much smother.

So totally check it out and not jsut align the marks up. Pull that plug and make sure by sticking a screw driver through the hole. With the marks lined up you should be able to stick it in all the way. If not that rear one is off.

 

[ZigsGSX97]

ok so more bad news.......started my car and let it run for little bit only to see black smoke coming out the tailpipe. the engine stalled. too much fuel was dumped. I have my safc settings at 0 all the way. I had the mechanic check the code because my check engine light came on. it spit a MAF code. I replaced it and it's still spitting the code and it's running super rough! i think my computer is f-ed up

 

[larsrya8]

And yes, running 550s with flat AFC settings will be very rich, and cause poor performance too.

I have my safc settings at 0 all the way

Why don't you try tuning it?

 

[ZigsGSX97]

i did try, but it's still running like ass no matter how much fuel i give.

 

[larsrya8]

Do you have any boost leaks?

edit: The 550's need you to inject 18% less fuel. Feed those settings into the S-AFC and see what it does. Unless you've already tried this.

 

[ZigsGSX97]

i don't think i have any boost leaks

 

[Maglin]

Well at idle it wouldn't be dumping to much fuel if their where boost leaks... It would be running lean. You need to check your wiring. I doubt your ECU is F'd up. Chances are your MAF is either messed up or it's just a wiring issue. I'm betting wiring... Now if you had a charge pipe disconnected you could maybe dump a bunch of fuel at idle as your turbo will pull a lot of air through the MAF and just dump to atmosphere.

 

[uberstrafe]

do you know if you have had your balance shaft removed, thatd give the vibration in that range!

 

[ZigsGSX97]

i replaced the MAF........also i don't know if the balance hsaft has been removed

 

[Dream On]

Do a compression check and post the results.

 

[ZigsGSX97]

ok good news everybody......i found out what made my car want to die.....compression test came up fine. Problem: the sensor type on my safc changed somehow. It was set to "hot-wire." I don't know if someone changed it or when i disconnected the battery it changed to that or what? But that's what made my car suck. I see my car every couple weeks ### i'm at college, and i came home and looked at the settings and they were wrong. It's all good now. Thanks for your help you guys!

 

[Maglin]

good to hear it was just user error. LoL I forget to think about those things. I guess you wouldn't think about checking settings either. But that would make sense though. Glad to hear it running right again.