OK guys, the studder/hesitation effect I experienced after the turbo was installed is gone, but now I have been noticing that it's more of a problem on the freeway.

For example, I'm cruising at 60 mph in 5th gear; I give it some gas to pass someone, etc, and the car "studders" or "hesitates". I also noticed this same problem when I try to accelerate from cruising (around 3K rpm) in 4th gear. When I rev it up in 1st, 2nd and 3rd, ie, as when racing, everything is normal; Get into 4th and 5th gear and the studdering begins.

Actually, I noticed that even in 1st or 2nd gear, if I floor it and try to accelerate really fast, the car will also "studder" really bad. Is this normal? And, if I slowly increase my foot pressure on the gas, the turbo will spool up smoothly, slight "pause" (I guess FPR lag and turbo spooling?) then it kicks in.

Could it be that I'm not getting enough fuel pressure at higher gears? I don't have an electrical fuel pressure gauge or an egt gauge yet, so it's kinda hard for me to tell.

Does anyone have any clue as to what could be causing this? Is it the way I'm driving or might there be a real problem. I've changed plugs and wires. Please help.

Thanx in advance,

fly1
http://fastgs.homestead.com/fastgs.html

sounds just like waiting for the turbo to spool. Even in a 4g63 with t25 if your cruising in a high gear and you floor it, it won't go anywhere for a second or two. Unless it's bucking really bad I think your OK.

Does your wastegate vent to open air? Do you ever hear it open ? ...if you're not sure, it's not opening. If your wastegate isn't openning, you're going to experience that stuttering when too much air gets rammed into the cylinders with waaaay too little fuel. I had the same problem once, due to an improper wastegate installation

-DarkOne
I'm so bad, i should be in detention.

LAST EDITED ON 17-Mar-01 AT 10:06 PM (PST)

I got HRC's super 16G w/internal wastegate. I just couldn't figure it out. When I stump on the gas (especially from a stop in 1st, then going to 2nd, 3rd etc) the car stutters, as if it wants to spool up but then something's holding the turbo back or something. But, at times everything is fine--the turbo kicks in and I'm gone. What's so irritating is that this problem seems to be intermitten--randomly. Sometimes the car runs good, sometimes it stutters. Please help! Arrrgh! Is there anything for me to look for? I've checked everything--vacuum lines, fuel, connections--they all look OK.

Later,

fly1
http://fastgs.homestead.com/fastgs.html

Could it be fuel cut?? What about trying to push it when it's in too low rpm's?? I duno... just guessing??

I'm not sure if it's fuel cut or not; my air/fuel shows "rich". I'm going to recheck and solder the fuel cut defencer device that came with my turbo kit. And, yes, if I floor it or go WOT, even at lower speeds, the stuttering or hesitation will also occur--most of the time.

Later,

fly1
http://fastgs.homestead.com/fastgs.html

hmm..if it is when you stomp the gas, i would try and look into the throttle position sensor possibly. Most ECU's have a throttle enrichment built into them, that when you crack the throttle hard, it richens the mixture instantly. Maybe your ECU isn't seeing this due to a faulty sensor. Just a suggestion though.

jason
95 GS Turbo

Have you checked your fuel mapper connection? That would cause small fuel cuts and then the stuttering you've described.

It better be solid or else....

Jason
98' Eagle Talon ESi-T
Mitsu Super 16g Turbo(HRC)


http://springfielddsm.homestead.com/JasonsPics.html

I checked the fuel mapper connection and it's secure; however, the installer used a glob of solder on the connection. I'll try to resolder those points.

I just don't get it. This afternoon, I revved it up from 1st through 3rd gear and the car pulled hard and smoothly. What's so puzzling is why it only happens sometimes. I double-checked all connections and they are all tight and secure.

Thanks for all the pointers guys!


fly1
http://fastgs.homestead.com/fastgs.html

To follow up with my problem previously, I may have found the cause. As you guys have advised, I checked/changed: spark plugs, wires, fuel filter, connections and the problem persisted; however, there was one last thing that I didn't check--the pcv valve. I did the pcv testing according to Chilton's manual and found the pcv to be bad. So I changed it.

Right away, I didn't notice any difference. But, by the afternoon of the next day, the car actually felt different. The car actually accelerates on the streets and on the freeway. Maybe it's just coincidence, but, all that problem because of a $2 pcv valve?

Could the pcv valve really affect the turbocharging performance?

~fly1
http://fastgs.homestead.com/fastgs.html

LAST EDITED ON 26-Mar-01 AT 02:48 PM (PST)

I REALLY hope that its just a PCV valve, because you have
*precisely* described the problem I had... and my car would only
do this sometimes too.... Unfortunately for me though, I had a
BRAND NEW Mopar PCV valve installed a few months before the
turbo... Damn.. I really hope that its that POS PCV valve..

The way I got around it was by "forcing" my car into higher RPMs
by downshifting before any hard acclelerating. But that isn't
always feasible, nor good for the clutch.

The funniest thing though is that no one understands what you are
talking about unless they have actually had it happen to
themsleves...

Good luck dude, I hope that that solved your problem, 'coz I can associate with how annoying it is...

Guy
RS_Guy



Keep all your fingers crossed people!
Looks like it's all falling in place finally...
I might actually be *driving* my car soon!
Its only been 5 LONG months...

Lean is Mean, Lean is Mean, Lean is Mean...

LAST EDITED ON 26-Mar-01 AT 07:34 PM (PST)

Well, I'm glad that there's someone out there that could relate to what I'm talking about here (you know what I mean). Not to dampen my previous good news post, but here in Ohio, the temperature is about 18 degrees and somehow, my car is doing what it used to do--"stutters". Darn it, so what, drastic changes in the weather is going to affect my car's performance too? I'll wait and see because it's supposed to warm up this weekend.

RS Guy, where did say you are located? Ohio?

~fly1
http://fastgs.homestead.com/fastgs.html