Application – 99’SS M6 Convertible.

Mods - Whisper Lid | K&N | SLP LS6 Intake | SLP LT’s | RT Cats | SLP Factory Dual/Dual |
MTI B1 CAM | Comp 918’s | MTI Push Rods | New Oil Pump | LS1 Edit

Summary – Last week I had B1 Cam package, and new oil pump installed, and dyno tuned with LS1 EDIT. Yesterday I had the Revlimiter bumped from 6500 to 6600 using LS1 edit, and drove the car for about 1 mile. Took of hard from a roll up to about 5500rpm’s and shifted hard. Stop at next light, take off slow and notice the Tach isn’t working, and the car is coughing and sputtering. Drove about 1 mile back to Installer. Turn off car and it won’t start up. Installer runs scanner – No codes only a lot of misfires. Disconnects battery for 5 minutes. Car Starts but runs like Hell.

What could be wrong???

Long version – B1 Cam | 918 Springs | MTI PushRods | New Oil Pump (Insurance) installed last week.

Last week - B1 Cam | 918 Springs | MTI PushRods | New Oil Pump (Insurance) installed

5/09 Thursday - Dyno Tuned using LS1 Edit
Driven 8 miles – Everything seems fine

5/10 Friday – Driven 50 miles - Everything seems fine

5/15 Wednesday – Driven 5 miles
- Went to installer to have a small coolant leak looked at.
- Intaller put new clamps an hoses going to H20 pump

Problem begins here – Ask installer to bump rev limited from 6500 to 6600?

- Installer bump rev limited to 6600.
- Start car up to head back to work. Everything OK
- Drive car for 1 mile turn around and pull it to about 5500rpm, and shift hard. Everything seems OK
- Stop @ light, take off sloe and notice the TACH isn’t working and car is now coughing and sputtering.
- Go back to installer
- Turn off car, Car won’t restart
- Runs the scanner No codes show, only a lot of misfires.
- Disconnect battery for 5 minutes, Starts up but runs like hell –a lot of misses.
- Installer suggests it could be crank or camshaft position sensor, or maybe a broken spring.
- Leave car to go to work.
- Installer removes valve cover to check Valve train – Everything seems normal

5/16 Thursday – Waiting to hear from Installer.

I’ll inform him of these possibilities. I read in another post -

- CKS needs Tech II to relearn. (What is Tech II?) – Team ZR1
- Rewire Crank Sensor, and replace Crank sensor – Pro Stock John
- Several Important wires that run near the #4 and #6 header primaries, - PSJ
- like one of the front 02 wires
- starter wires
- CKP wire.
- CKP Relearn - Vince
- Blown Fuse – Black Magic
- PCM/BAT
- 50 Amp Ignition Fuse
- Short Somewhere?
- Loose Ground Somewhere - XtraCajunSS

Thanks,
Bryan

<small>[ May 16, 2002, 10:22 AM: Message edited by: HOSS99 ]</small>

 

One thing no one mentioned as a possiblity is a bad ground. As you may imagine, in a car constructed like the Corvette ground points can be an issue. It is possible that one of the grounds worked its way loose during the time after the install and finally lost contact the day of the dyno tune...

Its just one more possibility.

Shane

 

Check the wires that lead from the crank position sensor to the PCM. The header on the pass. side could have burned through the wire, especially when the motor torques over @ WOT.

 

could be...
-huge vacuum leak
-broken valve spring(s)
-burnt wire messing up crank signal or 02 readings

most problems fall into 1 of 3 groups...
-mechanical: spring, vacuum leak
-fuel system
-electrical

I bet it's electrical but i do not have enuff info to know for sure.

 

I'm putting my money on crank position sensor issues due to the inoperation of the tach.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BurnOut:
<strong>I'm putting my money on crank position sensor issues due to the inoperation of the tach.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'm hoping it's that simple!!

 

Did I mention there is Valve train Noise too.

Springs, rockers, and pushrods, look good.

Installer now suspects a bad lifter, and is going to pull the drivers side head today. 5/20/02

 

Possibly a speed sensor?

 

The camshaft position sensor would also cause the tach not to work. But, I doubt that it would have a negative affect on performance. Almost sounds to me like you might have 2 seperate issues.

 

If your tach isn't working, try checking the guage fuse. I blew it out recently because I had 2 things wired to the empty plug below the fuse guage.. Good luck.