how to set the timing on a rb25det with a timing gun

[leesredgt]

ok i the cas off thiking i was going to get my covers powdercoated but end up runing short on cash so i had to scrap that plan. Any ways i put the cas back on so all i need to know is basically how to set timing/use the timing gun all i know is you got to pull the first plug or somthing?if someone could give me a step by step write up it would be gratly appreciated thanks in advance.

[rb25drag]

I made a plug wire that went from the coil to the spark plug #1 then I was able to use a timing light and you loosin the CAS to adjust the timing.

The wire I made I just took a plug wire I had laying around, Put a bolt in one end to run up in the coil and plugged the other end up to the spark plug as you normally would. Worked fine for me. Im sure there is another way of doing it. But that was the easiest.

[lilskyline240]

rb25drag want to take a pic of what you mean? i ahve no idea what you are trying to say

[Darius]

Yeah I'm confused too. You don't need to pull the coil pack to get the plug signal. Just attach the timing light to the white wire on the #1 coil and you're done.

[rb25drag]

Ill try and get a picture tonight. I have heard that white wire doesnt give a 100% accuracy. Thats why I made the wire. So I know its 100% right.

[Darius]

It would be interesting to see what (if any) difference there is between the white wire and your setup. Can you try both and give us an update of what you find? The FSM says to use the loop by the ignitor on S1 RB25's, so maybe try that too.

[rb25drag]

[IMG][/IMG] Make a plug wire. One end has a cut off bolt clamped to the wire as a conductor [IMG][/IMG] [IMG][/IMG] [IMG][/IMG] Put the bolt side in the #1 coil make sure it is a good tight fit so it dont come out. [IMG][/IMG] Plug the otherside onto the #1 Spark plug [IMG][/IMG] Then attach the timing light and now you can start the car and run the timing.

Hope these help!!!

[adam-gtX]

^I never thought of this man thats a sweet way to do it, is doesnt seem to hard either its just acting like it has sparkplug wires

[leesredgt]

so you just make a wire with a spark plug on it or do u just stick the end in there but then how far would you know to stick it into the cylinder.Any ways then cut the other end off and tape a bolt onto there and put it into the coil and then hook your timing gun to that wire and then just move the cas.Also does it have to be a wire that is for a rb25det or can i use some old ones off my mitsubishi 3000gt or any of my other cars?And were do i have to shine the light or do i have to worry about it using this method and just read what it says on the gun and move the cas.sorry if these r stupid questions but ive never used a timing gun and am learing.

Modified by leesredgt at 8:50 PM 10/9/2007
Modified by leesredgt at 10:02 PM 10/9/2007

[rb25drag]

Use a regular spark plug wire any kind will work v8 older model works best due to the straight end clamps vs a 90 degree clamp. If you take the boot off both ends you will see it has 2 metal clips, Do not cut the ends, If you spray WD40 on the boots they usually slide right off. one end snaps onto the spark plug thats already completely tight in the cylinder do not loosen the spark plug. The other end of the plug wire I just cut a 10mm bolt and clamped it to the wire so I had about an inch sticking out. If you look inside you coil it has like a spring coil that pushes down on top of the plug, so you have to put electric tape around the plug wire to build up the end so it wont fall out of the coil and it compresses the spring coil. Its pretty simple

After that you now have a lead wire for your timing gun, as a regular car would ok according to wat timing gun you have some run off internally battery power and some you hook leads up to a battery ground and hot wire. Now when you start you car you are going to have a bright flashing light coming off the timing gun. Its flashing per spark that cylinder is giving out. Your car should also sound normal should not mis. If it does you dont have good contact on that wire somewhere.

Now for the fun. The Crank balancer has 4 white marks and the timing cover has one mark thats indented in the cover. Each mark on the balancer represents 5 degree's starting from the right and going left. When you shine the timing light on the balancer you should see a mark on the timing cover and the balancer line up. If you wont to adjust it now take loose the 3 10mm CAS bolts and move it left or right according to if it needs advanced or retard. As soon as you get it lined up tighten up at least one bolt on the CAS and double check the timing with the light. Only moving the CAS slightly will move it a degree or 2.

If this still doesnt make sense you might need someone in person to explain it a little better. Timing is tricky.

[gawdzilla]

never had a problem taking the reading off the wire going to the coil. why make it so difficult?

[FriedEGs]

what's with all that extra work making a plug wire for it?!

Just use the wire that come's off the igniter that;s already looped out for you to use.. That's what the manual says to use, and it's accurate..

[rb25drag]

WELL I couldnt ever find that wire off the ignitor. Plus I have heard its not 100% accurate. Just wat I have heard. But using the plug wire I know for sure its 100% accurate and it only takes me about 25 secs to do timing now. ONly took about 5 min to make the plug wire. Just my opinion and way of doing things. Easier for me but maybe harder for you guys!!!

[nizmo zilvia]

Can you just use a spark plug wire?

[rb25drag]

Ya thats wat I used but your going to have to modify one end to fit inside the coil.

[jacksonbrown]

Thanks for posting this. Hadn't crossed my mind yet. This is a perfect way to hook up my timing light because it is a Matco with the digital advance/retard and hooking up to white loop throws the display way off . Reads about 4000 or so RPM at idle and is blinking the same but still shows the timing marks in general area. Hooking up with plug wire I can punch in 15 deg and it should line up on zero and the tach function should work right.

[tgxlayzie]

now when you set the timing do you also disconnect the throttle position sensor and im not 100% sure u set the timing 2 15degrees rite

[WhatsADSM]

I will add my info in here.

I actually had to do what rb25drag is talking about to get an accurate timing reading on my motor. When I used the loop wire I got invalid readings... Like straight out WRONG.

Here is the reason. Most (if not all) modern timing lights are set to trigger from the HIGH tension lead. This means the spark plug wire itself on the secondary side of the coil.

However on the RB the loop back wire is actually on the LOW tension side of the coil pack controlled through the ignitor.

So what was happening was this. My timing light was picking up on the increasing current in the LOW tension lead at the very beginning of the dwell. And it would fire the light. So I was getting a light that was occurring SIGNIFICANTLY before the actual ignition event. Doesn't matter if I used the black looped wire, or the white wire on the coil they are all the same. They are the low tension wires on the primary side of the coil and my timing light was able to pick up on the dwell current.

So in my case I was seeing values that said my timing was like 15-20 degrees more advanced than it was. Since I had an EMS I just quickly adjusted the dwell to run my "I think I know what is going on here" test and it verified what I thought. When I decreased the dwell the timing light would show a decrease in timing, which is flat out incorrect.

I then took a spark plug wire I had laying around, unscrewed the coil and attached the wire to the coil and the plug and checked everything again. (By the way there is no need to jam a bolt or anything in there the tiny spring should make contact with the coil and the wire just fine). This time when I measured with my timing light everything was spot on and when I changed the dwell it did NOT effect the readings.

Moral of the story... it just depends on how sensitive your timing light is. But very likely it could be an incorrect value when being read on the loop back wire or the white wire, on the primary side of the coil.... Because, well that is not how timing lights are designed to be used, they are designed to be attached to the spark plug wire itself (HIGH tension) on the secondary side of the coil.

Hope the explanation make sense.

[neonbomb]

Does anyone have a timing light that gives correct readings? I dont think mine is at all

[l0nestar]

Yup. I use an older Sun Test Equipment gun that is older than I am. It is chromed aluminum, fully rebuildable, and works like a champ. It was made in the late 70's and looks brand new.

Does anyone have a timing light that gives correct readings? I dont think mine is at all