tach & idle problems
Thread Starter
Heel & Toe
Joined: Dec 2006
Posts: 21
Likes: 0
tach & idle problems
1990 L 98 +.040 fast burn heads linginfelter cam int. base runners and plen. 1000 cfm tb runs great but the wife says it will go into a poor idle every once in a while and seems to run hot so here i am when i set it up i set the idle i used the car tach so i started there when i pull the tach mode up on the A C control readout it tells me the car is at 750 rpm when the tach says 1100 rpm that when it is not a bad idle my intent was to set it at a higher idle than that as per linginfelter adv. i think if i fix the tach and idle it to a acual 1100 rpm my idle gremlin would go away also the eng temp. gauge reads high other than that the car is a power monster
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
Unless the dash tach has been re-calibrated (even then)they are not very accurate. I would set idle (min.air)with either a scanner of laptop program, only if it was "hunting". You will also need to know what has been programmed in the tune for base idle speed (750 in drive, 850 in nuet. for a modded motor would sound about right). Overheating should not have anything to do with idle speed, fans will come on at a programmed temp. Your post could use some clarity, this is the best I could make of it.
Last edited by mseven; Dec 8, 2006 at 09:50 AM.
Thread Starter
Heel & Toe
Joined: Dec 2006
Posts: 21
Likes: 0
the eng is not overheating and the fans are working great it is just the gauge readout is off about 20 deg. from true temp and ratio gets worse as temp. rises when eng temp is at 210 deg the gauge is peged also the tach is the same at 3200 rpm on the scanner the tach reads 5400 rpm
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
You might try a new temp gage sender. Disconnect it and verify that the dash reads low - ground the lead and it should peg at max (300?).
That will at least verify the wiring and the gage.
That will at least verify the wiring and the gage.
