Slow moving RPMs
08-07-2018, 10:25 AM
#1
Burning Brakes
Thread Starter
Slow responding RPMs
Car is an 07z, had headers and intake installed so I sent out for a mail order tune last week. When the ECM came back, I reinstalled and while the front was up slightly I decided to just go ahead and lift the rear and do the muffler mod
While removing the passenger side muffler, I pinched the wires on the plug to the EVAP solenoid which is in that area. I guess it's a common thing to do from what I've read. When I pinched the wires, it sparked and I'm assuming it blew the #13 fuse for the EVAP and reverse lockout because when I drove this morning for the first time after tune and exhaust, reverse was tough going in.
However, the other thing I noticed is that my RPMs between shifts are slow to react. For example, shifting from 3rd to 4th, I have to keep the clutch depressed for a second or two, so that that RPMs drop low enough to engage fourth. And this is throughout all the gears. If I 'blip' the gas in neutral, they come up normal but come down slowly.
My question is, are the RPMs acting this way due to the tune and the ECM just has to relearn etc., or does the blown EVAP fuse have something to do with it? I won't be able to check the fuse till later this evening. Other thing I was considering is maybe I pinched some other vacuum line while removing the mufflers. Are there vacuum lines running above both sides of the mufflers, or just the passenger?
Thanks in advance
While removing the passenger side muffler, I pinched the wires on the plug to the EVAP solenoid which is in that area. I guess it's a common thing to do from what I've read. When I pinched the wires, it sparked and I'm assuming it blew the #13 fuse for the EVAP and reverse lockout because when I drove this morning for the first time after tune and exhaust, reverse was tough going in.
However, the other thing I noticed is that my RPMs between shifts are slow to react. For example, shifting from 3rd to 4th, I have to keep the clutch depressed for a second or two, so that that RPMs drop low enough to engage fourth. And this is throughout all the gears. If I 'blip' the gas in neutral, they come up normal but come down slowly.
My question is, are the RPMs acting this way due to the tune and the ECM just has to relearn etc., or does the blown EVAP fuse have something to do with it? I won't be able to check the fuse till later this evening. Other thing I was considering is maybe I pinched some other vacuum line while removing the mufflers. Are there vacuum lines running above both sides of the mufflers, or just the passenger?
Thanks in advance
Last edited by Konrad; 08-07-2018 at 10:41 AM.
08-07-2018, 01:30 PM
#4
Get the tuner on the phone.
The base cars will hold the RPMS a touch longer before they drop down as you come off the gas without touching the clutch pedal, but the Z06 will have a faster RPM drop rate once you come off the throttle isntead.
Plus, any pressure of the clutch pedal with it coming off the top of clutch pedal switch, should have the RPMs dropping instantly as well.
Or, you have a major vacuum leak in the intake manifold from the MAF rearward isntead.
The base cars will hold the RPMS a touch longer before they drop down as you come off the gas without touching the clutch pedal, but the Z06 will have a faster RPM drop rate once you come off the throttle isntead.
Plus, any pressure of the clutch pedal with it coming off the top of clutch pedal switch, should have the RPMs dropping instantly as well.
Or, you have a major vacuum leak in the intake manifold from the MAF rearward isntead.
Last edited by Dano523; 08-07-2018 at 01:34 PM.
08-07-2018, 01:38 PM
#5
Burning Brakes
Thread Starter
I've emailed the tuner and waiting to hear back, while I'm at work.
Really hoping I didn't cut some sort of a vacuum line when removing and installing the mufflers. I don't think there are any vacuum lines on the driver's side (correct me if I'm wrong), only the EVAP on pass side. But I think if the EVAP hose has a leak it won't affect vacuum. So I'm thinking there must be a different vacuum leak.
Really hoping I didn't cut some sort of a vacuum line when removing and installing the mufflers. I don't think there are any vacuum lines on the driver's side (correct me if I'm wrong), only the EVAP on pass side. But I think if the EVAP hose has a leak it won't affect vacuum. So I'm thinking there must be a different vacuum leak.
08-07-2018, 06:59 PM
#6
When taking to the tuner, mention the air system you installed, since he may need to tweak for the Maf reading as well.
Hence some air system cause nasty air turbulence problem at the Maf that the OEM air systems do not have, and the tune may needs to be adjusted for this as well.
Hence some air system cause nasty air turbulence problem at the Maf that the OEM air systems do not have, and the tune may needs to be adjusted for this as well.
08-08-2018, 08:43 AM
#7
Burning Brakes
Thread Starter
I agree, but all (2) my mods were listed.
So the EVAP/reverse lockout 25amp fuse was blown and I replaced it.
On my way to work this morning same RPMs symptoms. No CEL, which makes me think it's something to do with the tune. Still waiting to hear back from tuner.
So the EVAP/reverse lockout 25amp fuse was blown and I replaced it.
On my way to work this morning same RPMs symptoms. No CEL, which makes me think it's something to do with the tune. Still waiting to hear back from tuner.
