Pinging? Power loss on heavy throttle - GM Forum - Buick, Cadillac, Olds, GMC & Pontiac chat

2000-2005 Discuss your 2000-2005 Bonneville SE, SLE, and SSEi Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Pinging? Power loss on heavy throttle

Reply

 
 
 
Old 01-27-2018, 07:26 PM
  #1  
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jul 2004
Location: Minneapolis MN
Posts: 73
Thanks: 0
Thanked 3 Times in 2 Posts
Anything4APontiac is on a distinguished road
Default Pinging? Power loss on heavy throttle

2003 ssei with 171k, always run premium. I'm at about half tank and I just noticed this issue on this tank of gas. I'm in MN and temp is just below freezing. Car runs fine under moderate to heavy accel, but at about 75% throttle you can give it more gas, the car won't respond, and it actually loses acceleration and what feels like a miss, or an audible difference in the way engine is running. Perhaps the engine is trying to advance the timing to the point where it just starts to detonate? No CEL, no misfires. Plugs and wires have about 80k on them. I'm planning on running through this tank of gas, and try it again. If it still is happening, perhaps I'll replace plugs and wires. I ran a bottle of amsoil fuel treatment at the first of the month as a preventative measure. Fuel trims are fine. I thought I'd run it by the experts to see if they agree with bad gas. Car has an aftermarket MAP, TPS, and MAF, and ignition module, but the engine is stock except for a drop in K&N.
Anything4APontiac is offline  
Reply With Quote
Old 01-28-2018, 03:02 AM
  #2  
Senior Member


True Car Nut
 
Soft Ride's Avatar
 
Join Date: Jan 2012
Location: BC Canada
Posts: 3,923
Thanked 399 Times in 352 Posts
Soft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud of
Default

Ya when I hear on this tank of gas then issues, it is good to assume something'* up with the last fuel up.
Many premium fuels still contain ethanol, which likes to absorbs moisture. Who knows what was in the last tankful as well.
So, I would try a water remover product like Heet, with injector cleaner, & see if that helps.
Soft Ride is offline  
Reply With Quote
Old 01-28-2018, 03:32 AM
  #3  
Senior Member


True Car Nut
 
Soft Ride's Avatar
 
Join Date: Jan 2012
Location: BC Canada
Posts: 3,923
Thanked 399 Times in 352 Posts
Soft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud ofSoft Ride has much to be proud of
Default

I am glad that you do not have a CEL.
I would tho recommend replacing the spark plugs. By 80k miles, gaps will no longer be in spec.
New plug wires, not a bad idea as well.
Soft Ride is offline  
Reply With Quote
Old 01-28-2018, 05:02 AM
  #4  
Retired Administrator

True Car Nut
 
GunsOfNavarone's Avatar
 
Join Date: Apr 2009
Location: Williamsport, PA
Posts: 2,876
Thanked 173 Times in 134 Posts
GunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud ofGunsOfNavarone has much to be proud of
Default

Maybe a coil issue? Corrosion sometimes occur at the electric connection of the coils. It is fairly easy to inspect, just takes a few moments. Surprised you are not getting a misfire. flashing check engine light when the power fades.
GunsOfNavarone is offline  
Reply With Quote
Old 02-01-2018, 02:44 PM
  #5  
Senior Member


Posts like a Camaro
 
Join Date: Feb 2015
Location: Earth
Posts: 966
Thanked 155 Times in 139 Posts
CathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to behold
Default

Originally Posted by Anything4APontiac View Post
I'm in MN and temp is just below freezing.
So nice thick air, lots of oxygen.

Originally Posted by Anything4APontiac View Post
Car runs fine under moderate to heavy accel
So maybe gas isn't so bad?

Originally Posted by Anything4APontiac View Post
but at about 75% throttle you can give it more gas, the car won't respond, and it actually loses acceleration
. . . now the throttle plate is more open and vacuum is going down. More air going in more easily, and lower vacuum should have the fuel pressure regulator add more fuel.

Makes me want to ask: How'* your fuel pressure regulator?
CathedralCub is offline  
Reply With Quote
Old 02-01-2018, 02:49 PM
  #6  
Senior Member


Posts like a Camaro
 
Join Date: Feb 2015
Location: Earth
Posts: 966
Thanked 155 Times in 139 Posts
CathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to beholdCathedralCub is a splendid one to behold
Default

. . . and I agree, if these plugs have more than 80,000 on them or you are unaware of their status they should be replaced . . . and may as well replace wires while you're at it.

And yes, maybe the fuel is less good than previous, and maybe in combination with a marginal fuel pressure regulator this issue is popping up? I just can't get over the part where it runs fine at idle (I assume) and at moderate/heavy acceleration below 75% .

. . . and the fuel pressure regulator is easy to replace, and it probably needs one anyways if you are unaware of its status.

Last edited by CathedralCub; 02-01-2018 at 02:50 PM. Reason: Added [easy to replace] remark
CathedralCub is offline  
Reply With Quote
Old 02-01-2018, 11:57 PM
  #7  
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jul 2004
Location: Minneapolis MN
Posts: 73
Thanks: 0
Thanked 3 Times in 2 Posts
Anything4APontiac is on a distinguished road
Default

I didn’t get any heet before refilling at a different station. I tried it a couple times on the way home. The first time no issues, but a few miles down the road it was back, so might say intermittent. I hadn’t considered the FP. I will do a regulator too. Thanks for the suggestions. I’ll update again once I get the plugs wires and regulator swapped. I had tested coils awhile back but there could be a weak one by now. I have a few spares of those. I think there is a station that has true no ethanol premium I should try too.
Anything4APontiac is offline  
Reply With Quote
Old 02-09-2018, 11:39 AM
  #8  
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jul 2004
Location: Minneapolis MN
Posts: 73
Thanks: 0
Thanked 3 Times in 2 Posts
Anything4APontiac is on a distinguished road
Default

Update: Put in a new set AC DP plugs (no iridiums on hand) New Belden wire set, bottle of heet
Drove it around the section and the problem was still the same / unchanged. Drove to get gas and with the torque converter locked under light acceleration, there is a hesitation / jerk now feels like tc trying to unlock but doesn't. MY CEL is on due to a downstream O2, but I don't think that is the cause of issue. Filled it with no ethanol premium and on the way home and now it is missing bad under acceleration with a flashing CEL and P0300 multiple random misfire. I'm pretty confident I've been dealing with a miss all along, because it is the same symptoms, but happens at a lower rpm, and more violent, like more than 1 cylinder now. I'm thinking swap the plugs again for Iridiums and retest. I didn't put a FP regulator in yet cuz a guy I talked to said if they go bad its because it allows fuel to pass through when it shouldn't - floods out after hot soak. So if its starving for fuel, then it could be a fuel pump perhaps. Need a better scan tool. The old wires were basically welded to the plugs on the rear bank, what a pain. But get this, the new wire resistance was actually higher than the old ones I took out. If the old one was 300ohms, the new one was 600ohms. The old plugs looked barely used and still gap out at .060, but the shanks are well rusted. I'll see if Napa will let me defect out the DP'* and pay the difference for the Iridiums.
Anything4APontiac is offline  
Reply With Quote
The Following User Says Thank You to Anything4APontiac For This Useful Post:
Soft Ride (02-11-2018)
Old 02-09-2018, 12:12 PM
  #9  
Senior Administrator



Certified Car Nut
 
Join Date: Jul 2003
Location: Dark Side, NY
Posts: 16,262
Thanked 1,228 Times in 922 Posts
Mike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond repute
Default

What'* your fuel pressure?
__________________
2002 S10 V8
Please do NOT PM technical questions
Please do not reply to posts older than 6 months
Mike is offline  
Reply With Quote
The Following User Says Thank You to Mike For This Useful Post:
Soft Ride (02-11-2018)
Old 02-12-2018, 05:15 AM
  #10  
Senior Member
True Car Nut
 
rjolly87's Avatar
 
Join Date: Jun 2003
Location: Las Cruces, NM
Posts: 7,047
Thanked 380 Times in 300 Posts
rjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant futurerjolly87 has a brilliant future
Default

What oil are you running?
rjolly87 is offline  
Reply With Quote

Thread Tools
Search this Thread
Quick Reply: Pinging? Power loss on heavy throttle


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.