ursrob

Is there a way to check and adjust the timing?If so, can you list the steps involved to do so.Thanks in advance.It's on a 95 sc400.

Keith13b

iTrader: (3)

You check it the same way you do any car, cept' good luck changing it.

Clip the test lead over the plug wire, and fire the light at the pully. Check idle timing as well as full advance at 3500 rpm. Have a buddy rev while you fire the timing light....but like I said, not much you can do. An adjustable gun is nice, as you dial the light back till it hits TDC, then you read the advancement off how much retard you gave the gun. They cost a little more, but when you're tuning a car its almost a necessity.

Have fun. If youve never done it, find some one to show you as you probably wont get it just by reading. Its simple as checking the oil level on the dip stick, but confusing untill you're shown how to do it.

boredguy77

I don`t know if the 400 is different from most cars, but on most cars you get a timing light hooked to #1 cylinder, and make sure the light flashes when the marks on the dampener and block match up. for example on the sc300 you hook up the light to cylinder #1 connect two ports on the diagnostic port and start "timing it" if the white line on the dampener matches up with the 10 degrees btdc line you are good to go. if it doesn't you have to turn the distributor until they match. go here for more detailed instructions
http://mkiv.com/manual/manualtt/igni...ion/index.html

Pen

The ECU adjusts timing on the fly, allowing for fuel quality, driving style etc, so leave it alone.

boredguy77

although the ecu does adjust timing on the fly, if you bridge those two ports on the diagnostic panel it will remain constant so that you can adjust it without the computer adjusting it also. If his timing is off he wants to check it, not just leave it alone.

Pen

Curious, I wasn't aware that the bridge locked the timing.
Got any more info about that?
Does it just set it to factory default as if you had just done an ECU reset?
What would be the effect of driving with the bridge?
Would it lose the ability to adjust for pinging?

Keith13b

iTrader: (3)

Yes, but the bridge will lock out any advance, so you loose the retard during starting, and are always on full advance....not the best thing in the world, and I didn't know the 400 had that option......I don't think it does. Remember we have 2 distributers too.

The ECU will correct any changes you make, so its about pointless to adjust it. Hence my first post, and why its so hard to go over a 100 shot of NOS on a stock computer.

Frankinaustin

Timing is measured using no 6 Cyl. not number one. Not sure why. I checked mine before and after t-belt. 8 DBTDC.