VT V6 1997 Auto So a while back my VT started missing under light load when going above about 70km If i put my foot down i would to fine. So i dun a full service on it plugs leads fuel filter air filter oil filter oil cleaned the throttle body And it made no difference A week later it over heated so i looked into it more and worked out the head gaskets needed replacing so i put a vrs kit in it got the heads cleaned tested and skimmed cleaned intake to remove all the carbon deposits Replaced the intake gaskets flushed radiator and put in new coolant and bled the system by turning heater on fill getting up to temp and opening the bleed screw. Replaced fuel pump replaced battery (it failed sitting in the workshop for a week) the miss was still there and the other day it overheated again but it did not lose any coolant. i have been driving around for about a week and it has not overheated again . I'm stumped i don't know why its missing under light load i don't know why it overheated Ive checked the coil 6-3 6.04ohm 2-5 6.06ohm 4-1 5.96ohm ive checked the leads 1 1.61ohm 2 4.45ohm 3 2.67ohm 4 5.34ohm 5 2.63ohm 6 4.83ohm Does any one have any ideas Thanks guys
Did you Change the Thermostat also ? They can cause over heating problems. As for the Miss, Id say coil packs. I had the same issue coil packs only failed under load but tested ok.
When you bleed the system you really need a head of coolant above the level of the bleed screw as opposed to the pressure created when the coolant is hot. What I do to achhieve this is with the motor cool take off the radiator cap and insert a gatorade or coke bottle or similar at the cap end which has the bottom cut off it. I seal the cap end by wrapping it in electrical tape first so it pushes into the radiator. Clamp off the overflow tube and fill this bottle with coolant then undo the bleed screw, assuming there is no air trapped in the heater core this will remove any trapped air. Those spark plug lead resistance readings do you mean kohms? hort leads are good if below 10k (10,000 ohm) and long leads are good if below 27k (27,000 ohn) resistance assuming issulation is not damaged.
This is out of the Gregories manual. Ignition coil resistance (at 20 to 30 degrees) Primary: 3.8 litre V6..........0.3 to 1.5 ohms Secondary 5,000 to 7,000 ohms Spark plug wire maximum resistance. Left side.....10,000 ohms Right side...27,000 ohms
sorry for the late reply Thermostat was replaced with a new one i might try getting one coil pack n replacing one at a time n c how it goes what about the overheating?
Did you check the new thermostat and ensure it opens fully and @ correct temp? Pressure test both your cooling system and radiator cap, ensure it's relieving at specified pressure and the vacuum valve is working. Does it only overheat at idle, or while driving down the freeway or both? Thermofans kicking in?
i have not checked any think yet but today it was 37deg and the car was running at 104deg i was cruising at 80k with the ac on ill test the thermostat the radiator cap is new but ill check it how do i test the cap and cooling system (ensure it's relieving at specified pressure) and where is the vacuum valve and how do i test that yes the Thermo fans kick in
