engine shakes... AFTER HARD REV

[DSM_ThuNDeR]

Hey guys... I have just got my gsx to turn on a week ago and yesterday I have decided its time to go WOT! The turbo would spool and accel very good... the only problem is that when I rev the car Hard, the engine starts to shake like if it was in limp mode or something like it. I know the knock sensor is good.... what other things can I look for?
Oh, the spark plug wires are good, and so are the spark plugs. I used RRE instructions on how to make a wiring harness to use with the 1G CAS(did not sotter the conections) and also switched the injector trigger wires locations(just spliced them since I couldn't get the pins out, and did not sotter them). ALSO, the coil pack was inverted.
I have a 1g CAS in my 95 gsx

 

[Toxicangel]

do you have a data logger? how is your timing

 

[DSM_ThuNDeR]

actually I don't, I used a SIMPLE timing light to time my car (just made sure both marks at the crank were aligned while in idle). Thats 5 degrees advance right?

 

[interex]

Sounds like something is out of balance. I had this same type of "feeling" with a broken crank.

 

[redyute1]

its 5 degrees retard not advance

 

[v8s_are_slow]

Not sure what all you did and can only assume at what kind of vibration you had. But I'd check the crank pulley. Maybe shake it by hand. Also, what about your balance belt, do you have one? If so, you could've set the oil pump gear 180 degrees out. Flywheel tight?

 

[v8s_are_slow]

its 5 degrees retard not advance

There's only one 5 degree mark on the timing cover that I remember. Should be going from 0, 5, 10, etc. I do believe. Just make sure it's on the 5 and make sure you have the jumper wire hooked up when you're setting the timing.

http://www.vfaq.com/mods/wayback/BradBauer/engine/timing.html

 

[DSM_ThuNDeR]

Ok, I checked the crank pulley, NO FREE MOVEMENT OR PLAY. The mark that you are talking about is the "TDC" on the lower timing belt cover right? Plugged the timing light, once both lines were aligned, I tightened up the nut on the CAS.

The Balance shafts are removed and I know you are suppose to feel a little move vibration, but this is seriously way too much! Could this be because of a miss-fire? Once the Rpms go past 4K and come back down it starts to idle REALLY shaky and If I try to rev up I sounds like if the car is bogging and STILL SHAKES. What could this be?

Sorry about my poor english structure.

 

[DSM_ThuNDeR]

(ONLY happens once I rev it hard past 4K and the rpms go back to idle).... If I let the car sit for about 3 mins and turn it back on, It will eventually turn on and the engine will be really steady.

The balance shafts are removed and I know you are suppose to feel a little more vibration, but this is seriously WAY too much. The only mod I have are the b16G turbo and APR studs.... EVERYTHING ELSE IS STOCK!!

about the Timing, I lined up the "TDC" mark on the lower timing cover with the pulley, was this the right way or did I line it up wrong?

 

[v8s_are_slow]

Man, this could be a number of things. So apparently you've removed the balance shafts which means you did a timing belt job. Sure you got all the timing marks right when you put the timing belt back on? And as far as the crank pulley, it really doesn't matter how you put it on (as far as the vibration goes) but if you're setting the timing, it helps to have it on properly so that the mark on the pulley comes around when the #1 cylinder is firing. The pulley should only go on one way cause there's a pin in the crank timing gear that sticks out. Sometimes it gets pushed in though so maybe take off the pulley, look for the pin, and line up the hole in the pulley with the pin.

I had gotten the timing marks off on my timing belt once and it would vibrate. Dunno if that's your problem though.

What is your plug gap at? What kind of plugs do you have??? If it vibrates, pull one plug wire at a time. If it gets worse, plug it back in and go to the next one. If you pull one and the idle stays the same, that's the cylinder that's probably misfiring.

TDC is top dead center. The next mark is the 5 is where the mark should be when adjusting the timing.

Have any boost leaks? The car won't exactly run to perfection if ya have a leak.

Give more details if you've got em.

 

[DSM_ThuNDeR]

well I ended up finding out the problem! I tested the wires, coil pack, ect... and couldn't find anything UNTIL someone MR EVIL EAGLE mentioned about the timing. What I did was that I lined up the "T" on the lower timing cover with the crank pulley.... SO basically I was at zero! I advanced timing (not sure how much), gave it some hard revs, and car did not idle bad any more... Thanks man for helping me out!

 

[v8s_are_slow]

So are you saying you had your timing too low and it made your engine vibrate?!?!?

 

[DSM_ThuNDeR]

yeah man, thats what ended up making the engine shake after a hard rev... Weird huh?

 

[DSM_ThuNDeR]

hey guys.. the same problem has appeared again! I'm thinking it might be something throttle related wise...

When the Something is seriously wrong prob with my throttle body.. because when I open up the throttle plate while the engine is on I don't hear the intake manifold "sucking up air". Sometimes the throttle plate gets stuck(gas pedal is hard to break it loose from 0% throttle)... ALSO, the safc says sometimes the incorrect % of how much throttle im giving, For example:
When I have my foot off the gas, sometimes the afc will mark that I have 10%!!!! and the idle doesn't change nor the rpms... I know the TPS might be bad, but can this cause all that? all the throttle plate is really stiff at 0% throttle (kind of hard to break loose)

any info on that??

 

[rarson]

It's a cylinder misfire. It also sounds like your throttle is sticking.