Hesitation/Stumble under light load. Help - SRT Forums

staywide8 · 01-01-2010, 12:28 PM

So I had the car cmr tuned. 3076r setup w/750 cc's, return line setup at 58psi rising with boost, and of course 3 bars. Car runs fine any time its lower than 10 inches of vacuum, and runs fine under boost, but any time the vacuum is 11 or more, the car misfires. Anyone look at my file and see if anything is wrong? I was told it might be a scaling issue with the cmr tuner.

Deposit Files

ptperformance · 01-01-2010, 07:36 PM

Quote: Originally Posted by staywide8

So I had the car cmr tuned. 3076r setup w/750 cc's, return line setup at 58psi rising with boost, and of course 3 bars. Car runs fine any time its lower than 10 inches of vacuum, and runs fine under boost, but any time the vacuum is 11 or more, the car misfires. Anyone look at my file and see if anything is wrong? I was told it might be a scaling issue with the cmr tuner.

Deposit Files

What ignition parts do you have on the car?

staywide8 · 01-02-2010, 06:33 AM

Ngk 4306's, msd coil, and new stock wires

staywide8 · 01-03-2010, 07:00 PM

Any help?

ptperformance · 01-04-2010, 10:06 AM

Take off the MSD coil and put the stocker back on to see if the problem goes away.

goats srt · 01-04-2010, 10:11 AM

MSD coils are junk some people get real lucky with them but most don't

staywide8 · 01-04-2010, 10:13 AM

Would that matter if I don't misfire at any other time? Especially under boost. Just asking again, not saying anyone's wrong/right.

ptperformance · 01-04-2010, 10:16 AM

We have seen this a dozen times, pull the coil off the car and put the stock back on. It only seems to be a stuble that the MSD has issues with.

staywide8 · 01-04-2010, 10:19 AM

I will try it and report back. Can you see if the tune is scaled correctly on the 3 bar ptp?

ptperformance · 01-04-2010, 10:23 AM

I will need you to send me your tune file, send it to tunes@pt-performance.com.

This is the only way I can comfirm its correct, please make sure that you put some notes in with the email so I know what its in regards to.

Thanks.

staywide8 · 01-04-2010, 10:50 AM

I posted it in the thread. I can't send email while at work. Will the post work?

ptperformance · 01-05-2010, 09:12 AM

That is a datalog our your tune file? I really don't like opening up deposit files due to crap that can get attached but when I get home I will take a look at it.

Thanks.

staywide8 · 01-07-2010, 03:53 PM

Ok. Update. I loaded 2 different maps that should fix my car, but it doesnt. It caues my vacuum to read 13.5 ish instead of the normal 18.5ish. Checked baro with ko/eo and it reads 10.5. I checked both part numbers on the sensor and there both 3 bar sensors. With the maps though, my car does run and idle better.

staywide8 · 01-07-2010, 08:40 PM

Help!!

duster360 · 01-07-2010, 10:19 PM

Quote: Originally Posted by staywide8

Checked baro with ko/eo and it reads 10.5. I checked both part numbers on the sensor and there both 3 bar sensors. With the maps though, my car does run and idle better.

10.5psi Baro with KO/ EO just means the MAP/TIP sensor scales are jacked up in both maps. If you're actually in Dublin Ohio, your BARO and MAP at KE/EO should be right around 14.73psi as of this posting.