Expert: Roland Finston - 6/27/2011

Question
QUESTION: I have replaced the head gaskets on this 3.5l. got all timing marks back in line. The car starts rite up then dies. If I hold the gas pedal it will run smooth at 2000+ rpm. cannot find any vac leaks and replaced the iac. any thoughts or suggestions?

ANSWER: Hi John,
Have you tried for fault code using the ignition switch:"On-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time? Then watch the check engine light to see it begin to "flash-pause-flash, etc. Count the number of flashes before each pause. Then repeat to besure of an accurate flash count. Also you could watch the odometer window of the cluster to see if the mileage reading changes to show any 4 digit numbers. Let me know the flash counts or the 4 digit numbers or both and we'll see how these fault codes may give a clue as the the cause of the problem.
What you describe sounds like a large vacuum leak so check everything connected to the intake manifold and maybe see if you might have a leak somewhere around its exterior seal. Is the egr valve stem fully closed to a dead stop by the internal spring-action as that too can cause a no idle when it is ajar.
Let me know what you learn.
Roland
PS Sorry for the delay in responding but I just found your question in the 'pool' to which it had been referred by Kevin. Please "rate" my answer, and where you see the question about a nomination of me to be 'volunteer of the month' consider giving a 'yes' response.
Thank you


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QUESTION: Thank you for your responce   it has a 1255 flash code. as for the egr it appears to be working ok and is in the closed position.

Answer
Hi John,
The codes unfortunately don't point to any cause of no idle. The 12 just means that sometime in the past 50-100 key on-off cycles that the battery was disconnected, and the 55 just means 'end of readout' corroborating that a code readout was done.
There are a lot of vacuum lines that need to be verified: power brake booster, speed control vacuum reservoir, map sensor, evap purge solenoid for vapor recovery system, vac line to egr solenoid, fuel pressure regulator, pcv valve, intake manifold tuning valve assembly. So my suggestion would be to trace all those lines for leaks/connections/leaky device.
Roland
PS Please 'rate' my answer, and where you see the question about a nomination for me to be 'volunteer of the month' consider a 'yes' response. Thank you.