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-   -   trying to check timing, no timing mark (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/trying-check-timing-no-timing-mark-92901/)

Piranha 07-01-02 01:32 PM

trying to check timing, no timing mark
 
Hey guys, I'm trying to check my timing, and there is no timing mark on my pulley. It may have rusted off or something, there is decent amount on them. Is there another way to do this?

Also, I'm not familiar with how one checks the timing. I have a timing light... so what does a timing light tell you?

Thanks!

SaabGuy 07-01-02 01:38 PM

There should be 2 grooves which will be about 3/4 inch apart on that pully. What you do is warm up the motor a bit and then use a crayon to "melt" wax into the grooves. this will make it easier to see with the timing light.

Piranha 07-01-02 01:39 PM

thank you very much. So basically... the timing light is supposed to strobe as the mark hits the pin, correct?

Piranha 07-01-02 01:59 PM

Okay, I figured it out.

Okay, my L1 is right on the mark, and so is the L2. I don't understand how that works, but thats why I have help from you guys :P

My Trailing is VERY weird. It doesn't even fire on the mark, and it is very sporadic. Earlier I had the timing light out, and it was firing, but not very often, I thought that trailing fired twice compared to leading, and it seemed like it was going halfspeed. Well, T1 wasn't firing at all and T2 was sporadic. I had that green plug jumpered, and my idle got reallllly slow. The Green plug by the diagnostic plug. Anyone have some help? I'm going to check my trailing coil.

HAILERS 07-01-02 03:52 PM

The initial set jumper kills the feedback to the bac. Thats what causes the idle to drop. It also means that your idle is not set just right. The idle should be set to 750 with the initial set jumper in place. When your thru and pull the initial set jumper, the idle should stay at 750. What is happening to you now, is your idle is being set by the bac. The low idle you just mentioned is being brought up to the 750 by the bac's hard work. This is not good, because someday you'll turn on your a/c,lights etc and cause the bac to work even harder. Then when you come to a stop sign you'll wonder why the car stalled. its because the bac is having to work too hard. If the idle is set correct at 750 with the initial set coupler in place, the bac will not have to work at maintaining a 750 idle. Make sense????

On your timing. Only the T1 will shine on the trail mark. The T2 is not supposed to show on the mark. Only the L1 and T1. The light shining intermittently is a trait of this car, I believe. You'll find if you hold the inductor that goes over the wire at a certain angle, it will be a more consistent flash. Sometimes putting it closer to the sparkplug or closer to the coil will also make it flash more consistent. Its just a trait of the ignition.

Oh, L1 and L2 fire at the exact same time. This is not a truism for the trail plugs though. Read this item http://www.teamfc3s.org/info/articles/demystifying.html

You should bookmark the http://www.teamfc3s.org for future reference. Close to being the best rx web site.

BlackRx7 07-01-02 03:58 PM

so what happens when you block off you BAC?

HAILERS 07-01-02 05:07 PM

Block your bac off? You'll have to jack the idle up to some unreasonable figure like 900-1000 if you plan to keep the a/c etc. There's a throttle stop screw that can crack the plates open a touch more to get the idle you need/want.. Why anyone would block it off if beyond me, but its a free country to a point.

Piranha 07-01-02 09:03 PM

Yeah, thats why I haven't blocked off my ACV. I can't find what is wrong with my idle... either. I've tried looking for vacuum leaks, and I just can't find any. I dunno. I know I've damaged my engine a bit by running it and getting the detonation... but would it still idle okay?

Piranha 07-01-02 09:10 PM

I mean, BAC, not ACV. ACV is sitting somewhere as a conversation piece. People say "what the hell is that?" Oh, part of my car it doesn't need. WHAT??!!?

HAILERS 07-02-02 07:13 AM

Just a word about irregular idling. You look for air leaks and can't find them. Really puzzles you. Well there is a possible air leak you might not think about. On the whole the acv does not supply air to the intake air. It mostly goes to the exaust ports or the split air pipe.

Butttt.....during decelereation, there is a part of the acv called the anti after burn valve. Its internal to the acv. During deceleration it opens and lets air into the intake, then shuts off and seals itself. If this anti afterburn vales diaphram is cooked, it will let unauthorized air into the intake, and screw up your idle. Its aimed primarily to the rear rotor.

There is a test for this valve in the fsm. You disconnect the hose b/t the airpump and the acv. Start the engine and let it idle. Put your thumb on the inlet of the acv and feel for a suction. It should not suck. Then you rev the engine up and let go of the throttle. You should feel suction momentarily.

A note about acv in the turbo engines. The diaphrams cook, unlike in a N/a. If the diaphrams cook, the valve does not work right.

I've got a method of checking out the avv in the acv that is not conventional and not proven. Take the hose for the airpump off the air filter. Spray starter fluid for a split second into the air pump air intake. Does the engine idle increase. If so, suspect the avv in the acv being not so good. At least this method isn't as hard to do as pulling the hose b/t the airpump and acv off. Not fully proven method. It might be natural for some air to creep by the avv poppet. Don't know for sure yet.

Piranha 07-02-02 09:45 AM

But... I don't have an ACV ;) I got a block off plate :)

HAILERS 07-02-02 01:04 PM

I'll learn to read befor this is over. Anyway I've been meaning to write something about that possible internal leak in the acv and this provided the forum for it.


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