WOT Stutter
Jun 28, 2011, 03:04 PM
#1
WOT Stutter
Ok first off I used the crap out of the search so please don't be harsh.
My problem is at WOT in any gear I get a hesitation or stutter if you will.
I looked myself and decided to get some new plugs because it was about that time anyways, gapped them to 22 and threw them in. Didn't fix the problem.
Then I started searching the forums and found alot of different things like boost leaks which I had already tested for and vac hoses popping off. Mainly the ones connected to the EGR valve. Well I found a hose that was disconnected from the EGR and put it back on. Did another run and still the same thing. Also it is getting worse and worse. Went from maybe 1 or 2 times per gear and now it just keeps doing it like back to back.
Then I had a buddy hook up a scanner and found codes P0243 (Turbo/Wastegate Solenoid A Malfunction), P0420 (Catalyst Efficiency Below Threshold Bank 1), and P0401 (EGR Flow Insufficient).
So today after work I looked under the hood again to try and see if I could find any other vac hose that could have come off, mainly around the manifold/egr area and found nothing. So I took my negative cable off my battery for 2-3 minutes to try and reset my ECU. I took off from work normally and also noticed that when I would come to a stop that my idle would go a little bit lower than usual (around 500rpm) but then would come up after a while and might dip back down but never died. Experienced some even after at operating temp. So after I got to operating temp I did a 2nd gear pull to see if maybe resetting the ECU took it out of some "safe" mode or something but still the exact same thing. I even double check any hose that I could see or feel when I got home and nothing I could tell was off or out of the ordinary. The only thing is theres a hose coming through the firewall thats not connected to anything but I assume its from a boost gauge that was taken out.
My only conclusion is that the EGR is actually bad and the hose that was found a week ago was just coincidence, I didn't wait long enough to actually reset the ECU, or it is something else that I haven't found through searching. Any help would be much appreciated. I am trying to get this thing fixed for the track this weekend!
My problem is at WOT in any gear I get a hesitation or stutter if you will.
I looked myself and decided to get some new plugs because it was about that time anyways, gapped them to 22 and threw them in. Didn't fix the problem.
Then I started searching the forums and found alot of different things like boost leaks which I had already tested for and vac hoses popping off. Mainly the ones connected to the EGR valve. Well I found a hose that was disconnected from the EGR and put it back on. Did another run and still the same thing. Also it is getting worse and worse. Went from maybe 1 or 2 times per gear and now it just keeps doing it like back to back.
Then I had a buddy hook up a scanner and found codes P0243 (Turbo/Wastegate Solenoid A Malfunction), P0420 (Catalyst Efficiency Below Threshold Bank 1), and P0401 (EGR Flow Insufficient).
So today after work I looked under the hood again to try and see if I could find any other vac hose that could have come off, mainly around the manifold/egr area and found nothing. So I took my negative cable off my battery for 2-3 minutes to try and reset my ECU. I took off from work normally and also noticed that when I would come to a stop that my idle would go a little bit lower than usual (around 500rpm) but then would come up after a while and might dip back down but never died. Experienced some even after at operating temp. So after I got to operating temp I did a 2nd gear pull to see if maybe resetting the ECU took it out of some "safe" mode or something but still the exact same thing. I even double check any hose that I could see or feel when I got home and nothing I could tell was off or out of the ordinary. The only thing is theres a hose coming through the firewall thats not connected to anything but I assume its from a boost gauge that was taken out.
My only conclusion is that the EGR is actually bad and the hose that was found a week ago was just coincidence, I didn't wait long enough to actually reset the ECU, or it is something else that I haven't found through searching. Any help would be much appreciated. I am trying to get this thing fixed for the track this weekend!
Jun 28, 2011, 04:51 PM
#2
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p0401 Flow Insufficient is caused by the vac hose you found off. Scanned my car was throwing this code. Hooked the vac hose back up, cleared the code and that was that. It never came back. But when mine was off I never had any type of WOT stutter. So you could probably count that out as the cause of your problem. Good luck with fix.
Jun 28, 2011, 08:31 PM
#6
Ill step in here since I know the OP. The car was tuned at ams. I had the car almost a year ago and it was tuned from AMS, which I had gotten all the receipts from all the work done from the previous owner.
I did see you playing with the boost controller last friday. You sure you didnt turn it up a bit??
Hopefully you can get the problem figured out soon! Once you get a boost gauge, bring it over and we can test it up to a good 25-30 psi.
I did see you playing with the boost controller last friday. You sure you didnt turn it up a bit??
Hopefully you can get the problem figured out soon! Once you get a boost gauge, bring it over and we can test it up to a good 25-30 psi.
Jun 29, 2011, 04:13 AM
#7
Should have the boost gauge hopefully by the end of the week. Also all I did was mark the knob on the mbc to have a reference point but didn't have a wrench for the locking nut. But I did move it when I got home a couple days ago. Turned it down and no difference. The stutter has gradually gotten worse. I haven't noticed it getting any better or worse after any of the stuff I've done to it. Also I don't know how old the stock wires are and the plugs were just changed to the exact same ones that were in it. And it use to run fine. Not going to buy wires since I already ordered a Spark Tech NonCDI COP system. I guess I'll just have to wait until that gets here and hopefully it gets her going good. But I will fiddle with stuff until then to see if I have overlooked anything. Which I probobally have considering it's not fixed.
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Jun 29, 2011, 07:00 AM
#8
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You might be hitting boost cut. I would assume since it was tuned at AMS, they probably raised your boost cut limit but who knows until you hook up your boost gauge.
Another thing I thought of was compressor surge. But actual compressor surge is pretty violent so I doubt thats what it is. Food for thought
GL
Another thing I thought of was compressor surge. But actual compressor surge is pretty violent so I doubt thats what it is. Food for thought
GL
Jun 29, 2011, 04:12 PM
#10
Well like I said I don't know because I don't have a boost gauge and didn't have a regulator or gauge on the leak tester. Basically just an air hose directly into the tester. Found a small leak and tightened the boot up. Will be doing the leak test again once I get access to a tester.
Jun 30, 2011, 01:04 AM
#11
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Sounds like two separate problems to me. P0420 & P0421 are from that vac line. Zip tie it next time or do an egr delete and get a retune (I had this thing pop off so many times it made me keep my code scanner in my car).
P0243 could be a few things. Since you don't have a boost gauge in yet..
Turn your boost controller all the way down and see if you get the same stutter. If so, your wastegate isn't properly opening, mine stopped working on my car at around 80k miles. If turning down the boost controller fixes it, you were overboosting.
Either way, it's really helpfully to have a boost gauge. ESPECIALLY if your turning it up\down with a controller..
P0243 could be a few things. Since you don't have a boost gauge in yet..
Turn your boost controller all the way down and see if you get the same stutter. If so, your wastegate isn't properly opening, mine stopped working on my car at around 80k miles. If turning down the boost controller fixes it, you were overboosting.
Either way, it's really helpfully to have a boost gauge. ESPECIALLY if your turning it up\down with a controller..
Jun 30, 2011, 12:06 PM
#12
Did a boost leak test again today and the only hissing is coming from the throttle body/intake manifold area. Can't seem to pinpoint it, even with soapy water. Do you think the throttle body flapper shaft doohicky could be leaking. I got a bubble there once but never saw it again. Also is there a chance I'm hearing air thats passing through the throttle body into the intake manifold? I also "reset" my ecu again today after I looked for boost leaks and well it's still doing it. So do you think the EGR could actually be bad and the hose that was off about a week ago was just a coincidence? Also is taking off the neg battery cable really resetting everything or are there codes that need to be deleted with a scanner? I've also noticed that I've been getting a very low(400-500rpm) idle that happens alot now. Sometimes it will stay there until I take off and other times it will come back up to about 800rpm which is normal by itself. Just thinking maybe these issues are related and if so will maybe help pinpoint the issue easier. I know with my Honda's I use to have they had a big problem with the IACV sticking and causing weird idles and stuff so I didn't know if there was something on the EVO's that had some sort of simlilar issue of sticking or going bad. Also if anyone thinks they could help me out if I make a video so noone is confused on actually what it's doing I can do that. Just let me know. I'm just so frustrated with it right now I think I'm getting ahead of myself. Well any help is much appreciated, thanks.
Jun 30, 2011, 08:51 PM
#13
What you are hearing is the throttle body shaft seals I am sure. You still need to do a boost leak test once you have a gauge so you know how much pressure you are building up. I remember when I had that car, sometimes the throttle body would stick in the morning every once in awhile. Where I had to hammer the gas to free it up. My dd camry did the same thing, I just sprayed some carb and choke cleaner in the throttle body and it fixed that.
Not sayin that would fix your problem though lol. And you said you turned the boost down some and it still was doing it right?
I am still voting boost leak. It makes you think that you are putting plenty of air into the system. When I test mine out at 30psi, it takes some time for the compressor to pump 30psi into the system. For all you know, you could be only getting 10-15psi in the system, which wont bleed a whole lot out lol.
Sucks too, cause we are making a trip to the track again tomorrow.
Not sayin that would fix your problem though lol. And you said you turned the boost down some and it still was doing it right?
I am still voting boost leak. It makes you think that you are putting plenty of air into the system. When I test mine out at 30psi, it takes some time for the compressor to pump 30psi into the system. For all you know, you could be only getting 10-15psi in the system, which wont bleed a whole lot out lol.
Sucks too, cause we are making a trip to the track again tomorrow.
Jun 30, 2011, 09:58 PM
#14
I know. I want to go so bad. But I reset the ECU again and rode around a while and it seemed to reteach itself how to idle. I guess I just didn't give it enough time last time I had reset it after putting the EGR vacum hose back on. So I'm pretty sure the idle is fixed now. But the WOT stutter is still there. I am going to try and get the gauges put in soon since I got my boost gauge in today. I still might go to the track though. Just not with the EVO. 
I will be doing another boost leak test as soon as I hook up the gauge(s). The only weird thing is that I could hear it hissing and the soapy water wasn't bubbling at the throttle body gasket area. I'm so confused as why it would be hissing/leaking but not bubble if that's what is actually leaking. But I'll update as soon as I find anything else out. Thanks for everyones help so far. And for letting me use your boost leak tester. I'll get it back to you as soon as I figure it out or if you need it sooner let me know and I'll make my own.
I will be doing another boost leak test as soon as I hook up the gauge(s). The only weird thing is that I could hear it hissing and the soapy water wasn't bubbling at the throttle body gasket area. I'm so confused as why it would be hissing/leaking but not bubble if that's what is actually leaking. But I'll update as soon as I find anything else out. Thanks for everyones help so far. And for letting me use your boost leak tester. I'll get it back to you as soon as I figure it out or if you need it sooner let me know and I'll make my own.