Should I Get a Tune?

[Burnt Rice]

Hey all,

Mark here. Just wanted to know (and sorry if this question is asked tons of times, but I didn't see anything in the Search...) do you all think I should get a professional tune for my car? She seems to be a bit hesitant...I'll explain the problems she's having and I guess you guys can let me know if you think it's due to the fact she hasn't been tuned...

Ok, so, 99 GST (just so you know), there's only really two issues/weird...nesses... that throw me off and have me stumped. I had a mechanic check her out (inside and out) and he said there was nothing wrong with any sparks/injectors/engine components/etc. So this is why I bring it here: the first weirdness is the fact she doesn't stay at a constant rev speed when idle. The range is anywhere from 400 to 1400. It's not too harsh; definitely not just jumping up and down, but she slowly goes up and slowly goes down...sometimes stands still...etc. When I start her up (only sometimes) she doesn't seem like she's getting enough power to the engine. (Maybe a couple pistons were stuck in the compression stage?) The revs will stay between 200 and 500 until I rev the engine (just once). Then she, normally, returns to slowly inching from 4 to 14 and back down and so on. Sound like a reason for a tune?

The other thing which is weird (which I think I just figured out when [rallyturbo] explained what recirculating a BOV does) is the car smells like fuel and a bit of coolant a lot when I'm accelerating (even at normal speeds). Do you think it's because the BOV is open and therefore causing my fuel/air ratio to be rich for a second or could it be something else? The only thing I wouldn't understand is the coolant smell....maybe try recirculating the BOV and go from there?

Thanks for any help in advance...

 

[RvlutionMtrsprt]

Sounds like you need maintenance before tuning. Your idle problem is probably a bad ISC, easy fix. An atmospherically vented bov can cause rich conditions between shifts but if it's so bad that you can smell it, it's probably something else (boost leak, bad o2 sensor, etc). Coolant smell generally points to a coolant leak and/or burning coolant. Time for a coolant system pressure check there. Once all this is dealt with and you want to get the most out of your setup, then it's time for a tune, however the mods in your profile don't suggest that you have any sort of tuning device in your car.

 

[razrman8]

As far as your idle, I think what you are experiencing is "idle surge".Which can be caused by, like RvlutionMtrsprt said, ISC TB shaft leak, etc. Where your idle is not constant, and fluctuates. My GSX did the same thing. You could have a boost leak. Anytime you have a problem with and idle or a studder, I highly reccomend performing a BLT. It could be something as simple as a vaccum hose off of a nipple. But if not I suggest following this--->Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge) Basically the complete diagnosis to the surge. If indeed that is what it is.

 

[wkmitsu]

Yeah start with Recirculating your BOV. It sounds like your problem is more mechanical than tuning related. What you're getting is idle surge, which could be from a bad ISC. You could have a boost leak, testing that would be a good thing to do.

 

[razrman8]

^^ Agreed, it is something pretty simple, you just have to narrow it down.

 

[Burnt Rice]

Ok, so a boost leak is what I'm looking for...I'll check out that guide and see what I can find...as far as the coolant pressure check, I suppose I'll have the mechanic that was looking at it yesterday check it out again Friday. (This guy is booked throughout the week/weekend). Until then, I'll do as much as I can myself.

Thanks for the answers! I thought I might get slammed with that question for some reason. I'll check into it tomorrow when it's warm out. I live in Cali so anything under 60 is too cold to bare.

Thanks again.

 

[razrman8]

Anything below 60!
I'd kill for 60 right now.. its 20 here!!

 

[Burnt Rice]

Super necropost - I know.

I just wanted to say a few things:

1. The BOV has been recirculated and the hose from the block to the intake (Where a breather used to be) has been connected. Car runs better, but idles a bit weirder and almost stalls before starting up...

2. Got the lights back on. There was a short due to two disconnected wires touching each other going to the side marker light.

3. The guys at road race rewired the fans so that they are always on the "High" setting when on, and turn on earlier than usual. This brought engine temp down a lot (Thanks RoadRace!) but it's still too hot. They recommended getting a heat shield.

So, I have a couple requests that hopefully someone can help me out with on here:

Does anyone have or know where I can get (online) both a socket for my side marker light and a heat shield for the turbo? Also, with this much boost, I'm running my tires flat QUICK, and I wanted to get the rpf1's with a new set of tires, but can't seem to find an online dealer with 17 x 8.5's. Does anyone know where I can get these??

Thanks for any help!

 

[Grip]

When you got your care lowered did you have your camber and toe checked to see if they were in spec. You would be surprised how much that will effect tire life and just wear in general. I see your mod list but I don't see how much boost you were running.

Do you have a wideband at all to check your AFR when you are smelling that fuel?

I dont see a 16g putting that much heat out for a mostly stock car unless you beat the absolute piss out of the car all of the time. Maybe get your mechanic to check your thermostat and maybe even upgrade to one that opens at a little lower temp.