1993 Lumina Idling Problem

Tiny
S4MUS
  • MEMBER
  • 1993 CHEVROLET LUMINA
3.4L V6, Well, it looks like you have a ton of Z34 or Ordinary Lumina problems. So I will keep this short and simple. Idle's reeaaaally rough when at a stop light and acts like it wants to stall out RPM needle bounces between 0 and a little over 1. There's a really high pitched whining noice coming off the camshafts.

I have replaced these following parts to try and troubleshoot:

1: Plug Wires
2: Plugs
3: Coil Packs
4: ICM aka Ignition Control Module
5: Oil Change
6: Trans Flush & Filter Change
7: Air Filter
8: Fuel Filter
9: Windshield Wiper Blades? WTF, lol!
10: Tires & Complete Braking System Overhaul

Codes that are being thrown are:

34 & 48 <SPONSORED LINKS
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Monday, September 17th, 2007 AT 9:06 PM

5 Replies

Tiny
JACK42
  • MEMBER
34- MAP sensor signal voltage low
48-? Not listed

Has any other work been done to the engine? Rough like a miss? Do a comp test first to be sure you are tuning a solid engine. No vacuum leaks?
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Tuesday, September 18th, 2007 AT 8:03 AM
Tiny
S4MUS
  • MEMBER
The only thing I know is it has all new seals and the guy I bought it from said the motor had recently been rebuilt. I do know that the comp test came back clean, could it maybe be a timing issue? I know that with two camshafts no coinciding tends to have a issue with staying running. I think the other code was a Knock Sensor Error. I know there is no vaccum leaks other than the power steering fluid tends to go low every once in a while. I have a hinkling that the P.S. Pump has gone bad and the pulley is just spinning the belt free and too fast. Doesn't matter how perfect I get the idling pin set by ear or to the guage it still shudders and acts like it wants to stall and sometimes actually does stall out when coming to a stop. Any further advice or pointers would be greatly appreciated.

Thanks Again!
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Tuesday, September 18th, 2007 AT 12:17 PM
Tiny
JACK42
  • MEMBER
Has it run correctly since the rebuild? Looking at cam timing issues as the culprit. To time those engines the instructions must be followed to a "T" and it takes a few special cam holders
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Tuesday, September 18th, 2007 AT 12:52 PM
Tiny
S4MUS
  • MEMBER
It has sounded the same since I got the car a few months ago and then it just started throwing all sorts of codes, first the ICM, now the MAP Sensor and Knock Sensor. It doesn't mis-fire at all though, I wish there was a way I could record what the engine sounded like that way you can hear the whirring/whining noise coming from the passenger side of the motor.
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Tuesday, September 18th, 2007 AT 1:06 PM
Tiny
S4MUS
  • MEMBER
I performed a smoke test on the vaccum lines for the vehicle, A/C and Fuel. No leaks what-so-ever, so I'm thinking the cause for the surge in the vehicle is the MAP sensor and Knock sensor combination. Also I set the timing on it and it so far has solved the whining problem I had, it was only off by one tooth on the guage.
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Wednesday, September 19th, 2007 AT 7:38 PM

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