t8fanning Posted October 29, 2012 Report Share Posted October 29, 2012 I am having an issue with my top end boost. When I reach the higher ranges (from 13-14 psi) at around 3500 to 4000 rpm the boost varies. It kind of stutters and pops. It's hard too describe, but it drops a few psi and then starts to build again then drops again. I've adjusted the wastegate actuator to lessen the boost a little, but then I can't hit my target boost of 14 psi. I was thinking it may be a boost leak somewhere, but I couldn't find any, all my TCV lines are new and silicone, so I don't think the issue is there, could my wastegate actuator just be old and worn out? Any ideas what this could be, or any ideas where I should look? Thanks. Link to comment Share on other sites More sharing options...
EricF Posted October 30, 2012 Report Share Posted October 30, 2012 Stuttering is a great description for spark blowout, maybe. What spark plugs are you running, and more importantly do you know what they are gapped to? Link to comment Share on other sites More sharing options...
t8fanning Posted October 30, 2012 Author Report Share Posted October 30, 2012 I am running OEM Volvo plugs, I put them in this summer and gapped them to 0.028". But I didn't think of that. I'll check the gap this weekend. Link to comment Share on other sites More sharing options...
fst aslp Posted October 30, 2012 Report Share Posted October 30, 2012 I had a similar issue and I had it with NGK and OEM plugs... This is what I did: Link to comment Share on other sites More sharing options...
boxpin Posted October 30, 2012 Report Share Posted October 30, 2012 Provo, my daughter is going to BYU there and just crashed her 98 XC a couple weeks ago. My initial thought was a stock ECU and fuel cut off but then I see your running an ARD Green. I am going to second the ignition system and start with the plug gap. Hussein had some trouble with his COP a bit ago, just keep that in the back of your mind. Link to comment Share on other sites More sharing options...
t8fanning Posted October 31, 2012 Author Report Share Posted October 31, 2012 I had a similar issue and I had it with NGK and OEM plugs... This is what I did: Thanks for the link. I've been keeping tabs on your thread and may go down that route, but only if it's my last option. Provo, my daughter is going to BYU there and just crashed her 98 XC a couple weeks ago. That's what I'm doing as well. Mechanical Engineering student. That's too bad to hear about her XC, what color was it? I may have seen it. I was almost hit yesterday, drivers around here are horrible. Thanks for the input, I'm going to check my plug gap. I do have IPD HD coils, think they may be a contributing factor? Link to comment Share on other sites More sharing options...
NEU Posted October 31, 2012 Report Share Posted October 31, 2012 I do have IPD HD coils, think they may be a contributing factor? Hussein issues with his HD coils are the epoxy on the top of his were cracking. But he is running a very special set up that could be contributing to that. I have the HD coils, I bought them when they first came out and have had zero issues. Link to comment Share on other sites More sharing options...
Dan A Posted October 31, 2012 Report Share Posted October 31, 2012 I have HD coils with no issues as well. What about a weak CBV? Link to comment Share on other sites More sharing options...
t8fanning Posted November 1, 2012 Author Report Share Posted November 1, 2012 I don't think it's a CBV issue, there is no fluttering sound upon release of throttle, and I do have an IPD unit in and it is only a few months old. I know IPD units have been known to go bad, but I think mine is ok. Link to comment Share on other sites More sharing options...
t8fanning Posted November 4, 2012 Author Report Share Posted November 4, 2012 I checked my plug gaps. All were 0.028", I've been reading this thread: and it makes me think I have a leak in my intercooler piping. I am going to tighten the hose clamps on my snabb pipe, but what is the best way to check for leaks on the other intercooler pipes? Link to comment Share on other sites More sharing options...
t8fanning Posted November 6, 2012 Author Report Share Posted November 6, 2012 I checked all my soft intercooler hoses, they all looked ok; no cracks or cuts that I could see when I took them off. I checked my CBV just to be safe, it holds a vacuum just fine. Could this be MAF related? It's only stuttering at my top range of boost, could it be calculating the wrong amount of air and stuttering? Link to comment Share on other sites More sharing options...
fst aslp Posted December 10, 2012 Report Share Posted December 10, 2012 and resolve on this? Link to comment Share on other sites More sharing options...
t8fanning Posted December 11, 2012 Author Report Share Posted December 11, 2012 Yes. Turns out it was my ipd HD ignition coils. I replaced my old OEM ones and now it holds boost perfectly. Sent the HD ones back to ipd and they are still in the process of testing. So no conclusion as to what went wrong with them yet. Link to comment Share on other sites More sharing options...
lookforjoe Posted December 11, 2012 Report Share Posted December 11, 2012 Yes. Turns out it was my ipd HD ignition coils. I replaced my old OEM ones and now it holds boost perfectly. Sent the HD ones back to ipd and they are still in the process of testing. So no conclusion as to what went wrong with them yet. IPD did give me full store credit for the set I bought. What happened to me is that they overheat & shut down, then when cooled off, will function normally. So, if swapped out, they will probably test fine unless they run them for more than just a short time. Ken explained they have a (milliseconds) delay internally to build the higher intensity spark, but ME7 is able to compensate for that. Not sure what caused the problem for me, since mine is a ME4.4 hybrid. Link to comment Share on other sites More sharing options...
fst aslp Posted December 11, 2012 Report Share Posted December 11, 2012 Interesting, I never would have looked there. I may have to try a new set for mine. Link to comment Share on other sites More sharing options...
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