Rough idle, no misfires *Help ASAP please*
03-12-2005, 09:57 PM
#1
Rough idle, no misfires *Help ASAP please* Over the course of today it seems like the car has been idling real rough. I had recently put in some timing adjustments a few days ago (no KR) and thought it just needed to be adjusted some more. I also flushed my brake fluid, cleaned the engine bay, degreased the underside of the chassis with brake cleaner, replaced my PCV filter and air filter today.
Tonight I get P0102. Pull over, re-seat the MAF plug, and start scanning. My Bank 1 LTFT's are in the low teens, but bank 2 in the low single digits. Idle is rough, sometimes there's hesitation while driving. High LTFT's mean the O2 is getting unmetered air, right? The O2's are brand new Bosch vette rear's. I just checked the O2's yesterday and bank 1 was nowhere near that high.
Just checked all my fluids today in preparation for a autocross tomorrow and only the oil was down about 1/2 a quart (mid-hash).
When I started monitoring misfires, I would only see very spurious numbers on random cylinders, but they'd all fall back to zero. When I originally opened up misfire history on cylinders 1-3, I saw a number above 1000, and the next cylinder was real low. But now when I rescan the cylinder history on all banks, they are remain at zero.
I performed an HPT cylinder balance test, and the numbers were all within a few percent of each other. If I was getting misfires, I'd immediately think broken spring. I'm using 918's installed last Easter.I think I hear a mild tinking on the driver side wheelwell.
What do you think, guys? Should I look for an intake leak first or pull the valve cover?
The engine is hot now, so I'm not terribly keen on tearing into it until it cools. But I was planning on pulling the driver side plugs to see if they show any problems.
Tonight I get P0102. Pull over, re-seat the MAF plug, and start scanning. My Bank 1 LTFT's are in the low teens, but bank 2 in the low single digits. Idle is rough, sometimes there's hesitation while driving. High LTFT's mean the O2 is getting unmetered air, right? The O2's are brand new Bosch vette rear's. I just checked the O2's yesterday and bank 1 was nowhere near that high.
Just checked all my fluids today in preparation for a autocross tomorrow and only the oil was down about 1/2 a quart (mid-hash).
When I started monitoring misfires, I would only see very spurious numbers on random cylinders, but they'd all fall back to zero. When I originally opened up misfire history on cylinders 1-3, I saw a number above 1000, and the next cylinder was real low. But now when I rescan the cylinder history on all banks, they are remain at zero.
I performed an HPT cylinder balance test, and the numbers were all within a few percent of each other. If I was getting misfires, I'd immediately think broken spring. I'm using 918's installed last Easter.I think I hear a mild tinking on the driver side wheelwell.
What do you think, guys? Should I look for an intake leak first or pull the valve cover?
The engine is hot now, so I'm not terribly keen on tearing into it until it cools. But I was planning on pulling the driver side plugs to see if they show any problems. Last edited by JimMueller; 03-12-2005 at 10:03 PM.
03-12-2005, 11:33 PM
#2
Now the LTFT's are hanging out around +10 on both banks. If I had a vacuum leak, would it definitely be maxing out the LTFT's @ 25%? Still no misfires, no flashing SES's. Random P0102 and P0103's when I disonnect/reconnect the MAF. Brake booster is tight, AIR fittings on headers aren't cracked (like the EGR did before). The only part of the intake I messed with today was the lid, MAF & PVC.
I take off the MAF and Lid, the VE table takes over and the LTFT's drop to about -9, but it idles nicely (i.e., doesnt surge), albeit still roughly.
So this tinking sound... if it was a bent/broken valve or broken spring, I should be getting an SES. I didn't really pay attention to the oil pressure on the way home, but I know it was only a half quart low this afternoon, and ever since I realized I burned a quart in 500 miles, I've been checking it every couple of days.
I guess I'll hit the sack and hope someone has suggestions by the time I wake up around 6am.
I take off the MAF and Lid, the VE table takes over and the LTFT's drop to about -9, but it idles nicely (i.e., doesnt surge), albeit still roughly.
So this tinking sound... if it was a bent/broken valve or broken spring, I should be getting an SES. I didn't really pay attention to the oil pressure on the way home, but I know it was only a half quart low this afternoon, and ever since I realized I burned a quart in 500 miles, I've been checking it every couple of days.
I guess I'll hit the sack and hope someone has suggestions by the time I wake up around 6am.
03-13-2005, 12:15 AM
#4
OK, so I lied. I haven't gone to bed yet. I really need to though.
So what's the reason for disconnecting the battery? I'd find that humorous if it was a rocker arm, as a vendor recently told me to not switch to aftermarket.
So what's the reason for disconnecting the battery? I'd find that humorous if it was a rocker arm, as a vendor recently told me to not switch to aftermarket.
Last edited by JimMueller; 03-13-2005 at 12:43 AM.
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03-13-2005, 11:36 AM
#8
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ok ticking on the driver's side and fuel trims off on the driver's side. i see a header gasket problem. allowing air to get into the exhaust causing a false lean condition and trying to add more fuel to compensate.
03-13-2005, 12:08 PM
#9
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You just cleaned your motor? When I did my H/C my car had some of the same symptom's, many random missfires, 02's bouncing all over the place, MAF codes, then my gauges started acting up, some would work & some wouldn't. I tore down the top of my motor 4 times looking for bad ground's & pinched wiring harnesses. It ended up that when I washed down my engine before tearing it down I got some water in one of my computers connector pack's & it was shorting out across the pin's. I got lucky that I didn't fry the PCM.
03-13-2005, 12:29 PM
#10
I've got Stage 8 locking retainers on all but two bolts. The retainers haven't moved, and I checked the two without locks and they are tight. I can't see any exhaust leaks around the top of the gaskets - can't say about the bottom.
As far as the PCM weather packs, did you just disconnect them and blow them out?
As far as the PCM weather packs, did you just disconnect them and blow them out?
Last edited by JimMueller; 03-13-2005 at 01:18 PM.
03-13-2005, 12:59 PM
#11
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I blew them out, pulled the computer due to the fact that one or 2 of them were black from arcing & cleaned them with a pick & contact cleaner & cleaned all the sockets with a pick & contact cleaner.
03-13-2005, 01:18 PM
#12
Bank 2 plugs are out. Cylinder 4 tip is is much more white than all the others., which look normal. Most appear to have a bit of oil residue on the threads.
I just replaced the lifters last autumn, so I'm hoping it isn't another lifter. While I didn't see anything wrong with the stock lifters I removed, I put in Comp OEM replacements. The ticking I had on Bank 1 before the swap disappeared afterwards. Whether or not it was a lifter is up in the air. Although I like to believe I didn't replace them just because I was bored
I'll pull the PCM packs next and check the connectors. Then I'll pull the valve covers and look at the rockers and springs next since I'm already there. But since I'm not getting any misfires, I doubt I'll find anything.
I just replaced the lifters last autumn, so I'm hoping it isn't another lifter. While I didn't see anything wrong with the stock lifters I removed, I put in Comp OEM replacements. The ticking I had on Bank 1 before the swap disappeared afterwards. Whether or not it was a lifter is up in the air. Although I like to believe I didn't replace them just because I was bored
I'll pull the PCM packs next and check the connectors. Then I'll pull the valve covers and look at the rockers and springs next since I'm already there. But since I'm not getting any misfires, I doubt I'll find anything.
03-13-2005, 01:57 PM
#13
PCM ports look dry, none of the connectors look burnt to indicate arcing. There appears to be dust and/or very small sand at the bottom of the ports, so I'll blow that out.
I guess I'll remove the sticker and black marker writing from Ed Wright while I'm cleaning it up.
I guess I'll remove the sticker and black marker writing from Ed Wright while I'm cleaning it up.
03-13-2005, 05:45 PM
#15
Technically, yes, I do. However, I recently put on a new cat-back and the cut-out location changed to behind the axle. The motor is physically attached to the cutout, but the wiring is not connected.
Car's back together. No change.
Car's back together. No change.
Last edited by JimMueller; 03-13-2005 at 07:39 PM.
03-14-2005, 05:39 AM
#16
Just asking, becuase, I had a similar issue and my electric cutout wasn't working. It had '**** the bed'. The butterfly plate inside was loose and was futtering back and forth. This apparently threw the ECM off and it would sputter real bad at idle and then it started to do it when the engine was cold ... give it a little WOT, and it go completely go away ... guess the pressure was keeping it forced open completely and not allowing it to flutter.
I have the Borla adjustable exhaust with the QTP Borla electric cutout (behind-the-axle). It sounds like you might have the same setup.
I checked plugs, wires, injectors, wiring ... finally took the cutout off because it wouln't work right. The problem went completely away, immediately. The good thing is that QTP had no questions about rebuilding it. I just sent them $30 and they're replacing ALL moving parts and that covers shipping it back, as well. Hope this helps you man.
I have the Borla adjustable exhaust with the QTP Borla electric cutout (behind-the-axle). It sounds like you might have the same setup.
I checked plugs, wires, injectors, wiring ... finally took the cutout off because it wouln't work right. The problem went completely away, immediately. The good thing is that QTP had no questions about rebuilding it. I just sent them $30 and they're replacing ALL moving parts and that covers shipping it back, as well. Hope this helps you man.
