Power loss between 5500 and 5700
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Power loss between 5500 and 5700 OK I'll try to keep it simple. It's aY2K Z M6 with approx. 8500 miles. In third and forth gear there is a noticeable power loss between 5500 and 5700 rpm's, then after that point it continues to pull. I've A-tapped O2's stable .890-.905, 0 KR, timing climbs to 28* right before and stays there untill rev limiter. The MAF flow rate builds up to 35 to 36 lbs/min to 5500 then drops to 31-33 back and forth from 5500-5700 then back to 35 to 36 from 5800 to rev limiter. I swapped in a differnt MAF from a friends T/A and it's still there. <img src="images/icons/frown.gif" border="0"> Check plugs and wire connections and they are fine. Plugs are normal not fouled. Fuel filter has been changed and fuel pressure is fine. All induction connections are tight as well. Any ideas as to what to do next? I'm stumpped <img src="images/icons/confused.gif" border="0"> TIA for anyone's help!!! <img src="images/icons/grin.gif" border="0">
Staging Lane
Joined: Nov 2001
Posts: 58
Likes: 0
From: Kalamazoo, MI
Re: Power loss between 5500 and 5700 I had the same problem & I posted after hours of trying to diagnose it. I had one perosn reply with what seemed to be a strange reply.
The only reason I took it serious was it was only at that rpm that he claimed the loss was at too!
Well he was right on the money!!!!
Check you EGR tube where it goes into the intake. Make sure it is not cocked and that the o-ring is seated properly. In my case I thought yeah right .. and undid the 10mm bolt popped up the tube and my o-ring was seated at a funky angle. I realigned the o-ring & bent the tube back to correct angle .. tighted the nut...took it for a spin and it was cured! <img src="images/icons/cool.gif" border="0">
A 2 minute fix for something I was going crazy with ... I was about ready to check push rods and ect again!
Let me know if this did the trick!
Todd Rehr XLRATE
405.8 rwhp / 384.6 rwtq
'99 30th Anniversary TA WS6 (#1118)- M6: MTI lid , K&N, FRA, Fernco Coupler, TB bypass, Ported and polished TB, LS6 Intake, Cooling Fan Switch, Mac Headers and custom Y pipe (C&L high flow cats and FM collector), McCord 2nd Gen Power Cutout, SLP underive Pulley, MORE stage 2 CNC heads (2.08/1.60) & Comp Cam (216/220 - 525/532) & top end kit, Ed Wright programming, MAFT, KnockOut Box, Line-Loc, Harlan Shift Light, Pro5.0, Star Stage 2 clutch, 4:10s, Boxed LCAs, Nitto DRs(on 17" 30th rims).
[ November 30, 2001: Message edited by: TRehr ]</p>
The only reason I took it serious was it was only at that rpm that he claimed the loss was at too!
Well he was right on the money!!!!
Check you EGR tube where it goes into the intake. Make sure it is not cocked and that the o-ring is seated properly. In my case I thought yeah right .. and undid the 10mm bolt popped up the tube and my o-ring was seated at a funky angle. I realigned the o-ring & bent the tube back to correct angle .. tighted the nut...took it for a spin and it was cured! <img src="images/icons/cool.gif" border="0">
A 2 minute fix for something I was going crazy with ... I was about ready to check push rods and ect again!
Let me know if this did the trick!
Todd Rehr XLRATE
405.8 rwhp / 384.6 rwtq
'99 30th Anniversary TA WS6 (#1118)- M6: MTI lid , K&N, FRA, Fernco Coupler, TB bypass, Ported and polished TB, LS6 Intake, Cooling Fan Switch, Mac Headers and custom Y pipe (C&L high flow cats and FM collector), McCord 2nd Gen Power Cutout, SLP underive Pulley, MORE stage 2 CNC heads (2.08/1.60) & Comp Cam (216/220 - 525/532) & top end kit, Ed Wright programming, MAFT, KnockOut Box, Line-Loc, Harlan Shift Light, Pro5.0, Star Stage 2 clutch, 4:10s, Boxed LCAs, Nitto DRs(on 17" 30th rims).
[ November 30, 2001: Message edited by: TRehr ]</p>
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Re: Power loss between 5500 and 5700 Well I have thought about it. But it's intermittant so I've kinda ruled out a mechanical problem. I've bounced off the limiter a few times, but not from a 3 to 2 shift. I guess I'll check them tomorrow even though I don't have any valvetrain noise. I'm up for anything to fix this problem <img src="images/icons/mad.gif" border="0"> Thanx for the advice <img src="images/icons/grin.gif" border="0"> Any other thoughts from anybody will be considered and appreciated!!!! <img src="images/icons/cool.gif" border="0">
[ December 01, 2001: Message edited by: cool Z ]</p>
[ December 01, 2001: Message edited by: cool Z ]</p>
TECH Senior Member
Joined: Nov 2001
Posts: 7,234
Likes: 1
From: Mississauga, Ontario
Re: Power loss between 5500 and 5700 Try changing the plugs anyways, even though you've checked them. I had a bad hesitation on my 98 Formula above 5000rpms and changing the plugs cured it. To look at the plugs I didn't think they looked badly fouled at all to me, but they were still causing the hesitation.
Re: Power loss between 5500 and 5700 I have the same problem with my 99 SS. I only have about 1000 miles on my NGK TR-6's. I also do not have any valve train noise, so I can't justify pulling it apart to check the pushrods. I, on the otherhand do not have access to autotap, so I am considering taking it to the dealer to see it they can find anything in their computer. I am also thinking of "keeping it a secret" because I am considering trading it in on new one. By the way, mine started at about 44K miles an have also changed the fuel filter.
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Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Re: Power loss between 5500 and 5700 Thanx patman and silver slayer. I've have condidered just changing the plugs but looked at them and thought naaaaa. But I'm reconsidering that idea. <img src="images/icons/wink.gif" border="0"> I understand silver slayer, but this Z is exactly what I wanted and well I can't get another car for a while considering I'm one of those airline employee casualties <img src="images/icons/frown.gif" border="0">
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Verdad Gallardo Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Re: Power loss between 5500 and 5700 The EGR o-ring looked fine but I made sure the seal was reinstalled straight. Unfortunately this didn't solve my problem either. <img src="images/icons/frown.gif" border="0"> Thanks for the help guys and if anyone else has any ideas please post them.TIA
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Re: Power loss between 5500 and 5700 Well I checked the push rods today and all was normal. But' still loosing power 5500-5700. Thanx to all that have helped. I don't know what I'm going to do next. Anyone with suggestions please post them I'll try anything!!!!
Re: Power loss between 5500 and 5700 If the power loss continued up to the rev limiter, I'd say that you could have a weak spring with a valve float issue. There have been some stock engines that have had floating valves, but since the power comes back on, that theory is blown. Hows the injector pulse width at that rpm compared to just above and below? Another thing could be plug wires, but again, the power comes back on. Good luck
Brad
Brad
Re: Power loss between 5500 and 5700 [quote]Originally posted by cool Z:
<strong>Well I checked the push rods today and all was normal. But' still loosing power 5500-5700. Thanx to all that have helped. I don't know what I'm going to do next. Anyone with suggestions please post them I'll try anything!!!!</strong><hr></blockquote>
I know it has been a while, have you figured anything out yet. A friend has the Same EXACT problem....
<strong>Well I checked the push rods today and all was normal. But' still loosing power 5500-5700. Thanx to all that have helped. I don't know what I'm going to do next. Anyone with suggestions please post them I'll try anything!!!!</strong><hr></blockquote>
I know it has been a while, have you figured anything out yet. A friend has the Same EXACT problem....
Thread Starter
On The Tree
Joined: Nov 2001
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From: DFW,TX
Re: Power loss between 5500 and 5700 Yep!! I fixed it about 2 weeks ago after ruling out all kinds of fuel and ignition possibilities. I replaced the valve springs with LS6 valve springs and problem solved!!!!
<img src="graemlins/camaro.gif" border="0" alt="[Chevrolet]" />
<img src="graemlins/camaro.gif" border="0" alt="[Chevrolet]" />
Re: Power loss between 5500 and 5700 I have had the Same problem as well. were you able to get any ATAP data before you swapped the springs in? My car was showing missfires on 1,8, and 3 only at those rpms. Mine was intermittant as well so I never though about changing the springs. I must might have to try this. and get a new cam while Im at it <img src="gr_stretch.gif" border="0">
Re: Power loss between 5500 and 5700 [quote]Originally posted by MyLS1Hauls:
<strong>If the power loss continued up to the rev limiter, I'd say that you could have a weak spring with a valve float issue. There have been some stock engines that have had floating valves, but since the power comes back on, that theory is blown. Hows the injector pulse width at that rpm compared to just above and below? Another thing could be plug wires, but again, the power comes back on. Good luck
Brad</strong><hr></blockquote>
Well I was thinking the same thing.. But, now he is telling us that new springs fixed the problem??? Wouldn’t valve float come and stay, not come, clear up and pull till the limiter?? I know it’s not the plugs in my friends case. Last weekend we just put another new set of plugs and put the stock wires back on. Checked the EGR O-Ring and wrapped tape around it to make it seal better if it wasn’t. It feels exactly like it pulls out timing and then comes back??? But we get no Knock Retard… I feel like I am working on my Turbo Regal again.. <img src="gr_eek2.gif" border="0">
Still confused
<strong>If the power loss continued up to the rev limiter, I'd say that you could have a weak spring with a valve float issue. There have been some stock engines that have had floating valves, but since the power comes back on, that theory is blown. Hows the injector pulse width at that rpm compared to just above and below? Another thing could be plug wires, but again, the power comes back on. Good luck
Brad</strong><hr></blockquote>
Well I was thinking the same thing.. But, now he is telling us that new springs fixed the problem??? Wouldn’t valve float come and stay, not come, clear up and pull till the limiter?? I know it’s not the plugs in my friends case. Last weekend we just put another new set of plugs and put the stock wires back on. Checked the EGR O-Ring and wrapped tape around it to make it seal better if it wasn’t. It feels exactly like it pulls out timing and then comes back??? But we get no Knock Retard… I feel like I am working on my Turbo Regal again.. <img src="gr_eek2.gif" border="0">
Still confused
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Re: Power loss between 5500 and 5700 F1 changing the springs was the last resort. It didn't make sense to me either. But when the rocker arms were off, I could push down on the valves and they would open right up <img src="gr_eek2.gif" border="0"> Installed the LS6 springs, and I could barely get the valves to move when I would push on them. The stock springs were so weak, I and a few others that did the valve spring swap for me were surprised that I never bent a valve. $94 dealer cost on the springs, $200 labor = fixed problem.
<img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
<img src="graemlins/fluffy.gif" border="0" alt="[Fluffy]" />
<img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
<img src="graemlins/fluffy.gif" border="0" alt="[Fluffy]" />
Thread Starter
On The Tree
Joined: Nov 2001
Posts: 157
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From: DFW,TX
Re: Power loss between 5500 and 5700 Bad habit, autotap would show #1 and/or #5 and sometimes one or two others mis-firing. No codes or SES tho. Also, It would lose power at 5600 RPM's at part throttle in any gear. Just accelerate and give it enough gas to get it to rev that high and man I tell you it was like it hit a brick wall on the tach and it felt like the brakes were engaging <img src="graemlins/gr_barf.gif" border="0" alt="[barf]" /> . Definately more noticable than WOT runs. Give it a try!!!
Re: Power loss between 5500 and 5700 I think Ill try that when I get my car back from the dealership today (hopefully) did you try swapping out injectors from one cylinder to another to see if the miss followed the injector?
While the car was at the dealership they just happened to toast the clutch so I am getting a whole new clutch assembly out of them <img src="gr_grin.gif" border="0">
While the car was at the dealership they just happened to toast the clutch so I am getting a whole new clutch assembly out of them <img src="gr_grin.gif" border="0">