compression test?

Question

anyone tell me what fuse is the best to take out when doing a compression test on a car

Answer 1

Hi there it depends on the vehicle but as a rule of thumb:
1 remove fuel pump relay and find the pressure bleed off valve on the injector rail and de pressureize the systom, this ensures that no fuel will be injected when the ignition goes live.

2 Disconnect the feed to the distributor or coil pack to ensure there is no spark when your cranking the engine.

3 You need to ensure the throttle is fully open when carrying out a dompression test or the volumetric efficiency wont be correct

4. if your doing a compression test im guessing you have an issue with the engine so you need to do a dry test , record the results and then do a "wet" test do do this you squirt a little bit of oil down the bore and crank the engine for 3 seconds, this will tell you iff the rings are leaking as the oil will seal the piston rings when your testing.

good luck any questions let me know and ill try to help

Answer 2

It ability that they took a tension length of the compression generated by using the pistons vacationing up the cylinders. A bypass shows that the pressures are interior the producer's tolerances for engine placed on or harm and that maximum critically different cylinders have been interior of 5% of one yet another indicating the engine in is a continuing state. that declares with a lifelike degree of fact that: a million) the top gasket is sealed 2) The cylinder partitions are actually not cracked 3) The cylinder head isn't cracked around the compression chambers (examine on nonetheless) 4) The pistons and jewelry are in a serviceable condition 5) The inlet and exhaust valves interior the cylinder head are in a serviceable condition There are different forms of leaks and cracks that are actually not detected by using a compression attempt. on your case you in all probability have a leak between the water jackets and oil jackets that may not affecting the cylinders and consequently compression. i assume that the top gasket became into those days replaced given which you had previous hassle. consequently regrettably I are waiting for that the two the cylinder head is cracked or corroded between the oil and water jackets (probable) or that the engine block is cracked between the oil and water jackets (not likely) or that head gasket continues to be not sealed with the aid of undesirable setting up or warped cylinder head (conceivable if the mechanic is incompetent) Any way you look at it that's not good information sorry. teef_au

Answer 3

you dont have to remove any fuses.just take out all plugs and insert a compression guage into the plug hole and crank the engine over and read the guage.oh!iam sorry friend,i know now what your talking about.you want to disable the fuel pump.just take out the fuse that runs the pump.iam sorry about that.

Answer 4

Fuel injector fuse. If your vehicle doesn't have a dedicated injector fuse, you can disable the fuel pump but run it before pulling the spark plugs to relieve pressure in the system - it may start for a few seconds before it runs out of gas even with the pump is disconnected.

Answer 5

Why take out a fuse? Just disconnect the main wire from the distributor or pull all the plugs first. You are testing all the cylinders, right?

Answer 6

pull the coil wire to the distributor cap...remove 1 spark plug ...install compression test gauge...crank engine....stop cranking watch gauge for bleed down of pressure

Answer 7

Pull the connection at the distributer and the fuel pump relay/fuse out.

Answer 8

fuel pump or pull distributor wire center one and ground it

Answer 9

no need to take out anything once the ignition if turned of