Help: Car wont idle with new cam....
02-18-2006, 11:04 AM
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Help: Car wont idle with new cam.... The pcm was tuned mail order by Bryan Herter.....
Cam is a TSP 233/239. New injectors, springs/retainers/seats/seals were installed along with the cam.
Car seems to idle when cold but as soon as the motor idle drops down it dies. It is hard to keep running even with foot on the accelerator. I opened up the throttle body blade a little, but still wont idle. When it does run when cold, the engine feels "lazy" and doesnt rev up, like it is overly rich?
Shop that did the install removed the upper intake so maybe there is a vacuum leak? I am showing 11" of vacuum when it is running.....
We also swapped a rear o2 to a front, but I doubt this would have anything to do with it?
Any suggestions would be appreciated...
Cam is a TSP 233/239. New injectors, springs/retainers/seats/seals were installed along with the cam.
Car seems to idle when cold but as soon as the motor idle drops down it dies. It is hard to keep running even with foot on the accelerator. I opened up the throttle body blade a little, but still wont idle. When it does run when cold, the engine feels "lazy" and doesnt rev up, like it is overly rich?
Shop that did the install removed the upper intake so maybe there is a vacuum leak? I am showing 11" of vacuum when it is running.....
We also swapped a rear o2 to a front, but I doubt this would have anything to do with it?
Any suggestions would be appreciated...
02-18-2006, 11:10 AM
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Originally Posted by dwayneracing
We also swapped a rear o2 to a front, but I doubt this would have anything to do with it?
Any suggestions would be appreciated...
Any suggestions would be appreciated...
02-18-2006, 11:15 AM
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I am still using the front wiring harness. I just brought one of the rears forward and plugged it into the front plug, so if front and rear o2s are the same, then it should be ok?
02-18-2006, 11:56 AM
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The Corvette parts manual has different descriptions and part numbers for the front and rear O2 sensors. The front is:
SENSOR, HTD OXY (POSN 2)(PRE-CONVERTER)(ENG-OUT)
part number is 25312184
The rear is:
SENSOR, HTD OXY (POSN 3)(CATALYST MONITORING)(POST-CONVERTER)
There are two different part numbers for the rear sensor depending on model year. 98-99 is 25312202, 00-02 is 25317697.
Sounds to me like the front and rear sensors are not the same.
SENSOR, HTD OXY (POSN 2)(PRE-CONVERTER)(ENG-OUT)
part number is 25312184
The rear is:
SENSOR, HTD OXY (POSN 3)(CATALYST MONITORING)(POST-CONVERTER)
There are two different part numbers for the rear sensor depending on model year. 98-99 is 25312202, 00-02 is 25317697.
Sounds to me like the front and rear sensors are not the same.
02-18-2006, 12:12 PM
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Front and rear o2 sensors will interchange. The different part # for the front and rear on the vette may be due to one being longer than the other.
I have swapped them without issue. I think your tune probably sucks. Most cars will idle just fine when cold because you are in open loop.
I have swapped them without issue. I think your tune probably sucks. Most cars will idle just fine when cold because you are in open loop.
02-18-2006, 04:35 PM
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I have efilive scanning tool (professional version)but not too sure how to use it yet 
...not to mention I am not sure I can keep the car running long enough to determine what the problem is!
...not to mention I am not sure I can keep the car running long enough to determine what the problem is! Trending Topics
02-19-2006, 12:52 PM
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I think you need to visit a tuner, mail order can only do so much. I to think it's the tune. That cam is a respectable size and I would expect you will need to mess with the TB blade adjustment or drill the hole bigger to get sufficiant air in at idle, but thats just one issue to tune.
02-19-2006, 04:16 PM
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wow this post scares me cause i was gonna go with a mial order tune for a cam bigger than he went with....can u not mail order tune a big cam?everyone i talked to PCM4less, TSP, and a few others told me they could get me close to where i wanted to be
02-19-2006, 05:25 PM
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Bryan Herter is PCMforless. If the tune is off, I am sure he will take care of it. It didnt seem like he thought it would be a problem when I ordered the tune. I will let you know how it goes in the next couple of days.
02-19-2006, 05:28 PM
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try adjusting your tb set screw, put almost max open to where you idle at like 2k, then slowly work your way down to a decent stable idle that wont cut out on you. I have no tune and I have a f14 w/a4 and i DD it. Its possible.
Ski
Ski
02-19-2006, 05:32 PM
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just go my mail order tune back from tsp, jason did a great job got it on the first try.
runs a little rich but it is set up for a 100 shot. It didnt want to idle that great but i turned up the screw on the tb and that fixed it. As for mail order tunes not working for large cams i have the MS3
runs a little rich but it is set up for a 100 shot. It didnt want to idle that great but i turned up the screw on the tb and that fixed it. As for mail order tunes not working for large cams i have the MS3
02-26-2006, 11:48 PM
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Originally Posted by dwayneracing
The pcm was tuned mail order
You're tuner not being in the car, in the city, in your weather makes a big difference.
02-26-2006, 11:52 PM
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Originally Posted by Drewstein
And you're shocked it won't idle?
You're tuner not being in the car, in the city, in your weather makes a big difference.
You're tuner not being in the car, in the city, in your weather makes a big difference.
02-27-2006, 08:59 AM
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Originally Posted by Drewstein
And you're shocked it won't idle?
You're tuner not being in the car, in the city, in your weather makes a big difference.
You're tuner not being in the car, in the city, in your weather makes a big difference.
02-27-2006, 11:53 PM
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Originally Posted by Steel Chicken
except for people with bone stock cars, I never understood the desire to roll the dice on an email tuner....theres SO many variables to consider with modded cars, especially with cams.