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Discussion Starter #1
I have a 94 cobra 5.0 which I have installed a PIH kit and A9L computer. I set my initial timing to 14 degrees and it runs great. My questions: Is there a preset amount advance built into the computer. Do you know how much advance the A9L has in it. The distributor doesn't have any advance,Right? only the computer. After I set my timing and put the spout back in , I looked at the timing marks and speeded the motor up. It seemed like the timing advanced a bunch as soon as I touched the throttle. I couldn't read the numbers, it just seemed like a lot very fast. Can you speed up the motor and watch for the total timing or would you have to rev it real high, and are there other factors could change it. I guess I just know how to set the initial timing , but don't know where I stand as far as total. I see postings where guys with blowers mention 22 or 24 as a total. How do they determine that? I'm just an old fart from the old days of "If it's got gas and spark it's O.K.!
 

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The timing tables in the EEC are based off of 10 degrees initial timing. The GT is set at 26 total degrees at high load/rpm. So....to get 24 degrees total, you would have to back your initial timing down to 8. If you are looking to retard timing for boost reasons, you would be better off having a Boost Retard setup, or a tuner of some sort so you don't loose bottom end torque. I am running 21 total timing, however, at times my car sees 40. This is due to the computer adding timing at low loads and EGR input. This is why your timing jumps all over when you rev it a little. There is no mechanical/vacuum advance. It is all computer controlled.

I am not sure what the Cobra tables are. Have you checked out the Yahoo Group EEC-Tuner? They have tuner files and such that you can look at to get exact tables.

Of course...I just noticed you have the PIH setup...the load and such is setup differently on those computers. I am not terribly familiar with the old A9L setup.
 

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Thanks for the info: When you mentioned about the timing jumping up and about no load etc. it made me think of something. Not long ago I started my car to warm it up since it hadn't run for a while, the roads were messy, so I thought I'd just warm it up to operating temp and then put it away. I started it and put a shim under the throttle body so it was running a steady 2500 or so rpm's. After 5 minutes or so I noticed that the headers were turning a dull orange. I brought the engine back down to idle and it immediatley went away. I was just wondering if sitting there with no fan, and no load at that rpm if the computer was allowing the timing to go way up , really heating up the headers. I had a post about this and one guy mentioned that under no load the computer puts a lot of timing in it. I am running an initial of 14 degrees. Does this sound like a possibility to you? Thanks
 

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TOTAL TIMIMG

For a Carb'd car all my timing is in by 2200 rpm so i just rev the car to 2400 rpm and set my timimg at 36 to 38 total...I'm not concered where it's timed at idle just as long as i have 36 to 38 total at 2200 rpm..:)
 

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Wow Aaron,

That doesn't sound good, but I have never tried it. Let me throw something else out. Have you looked at your harmonic balancer? The outer ring is very common to slip, where your timing could be off by several degrees. You need to make sure your pointer is really pointing where it is supposed to. Most people don't find this out until they install some power adder and can't get rid of detonation. They usually find out they were running 14* or better when they thought they were set at 10*. I changed mine out when I added my Kenne Bell, to be on the safe side.

The days of tuning total advance the way PURESTREET5006 mentioned are over, if you are going to stick with EFI. This isn't a bad thing, as you can set timing based on load instead of curves via springs, which is great for driveability, if you know where to set them....not saying I do. :) Bad side is, it is more complicated.

Like I mentioned before, I do not know much about the A9L, but you might want to post in the EEC-Tuner forum here or on Yahoo Groups. I hear the A9L isn't as agressive in timing as the T4M0. If you were doing that with my car, you would be at about 40 degrees, if it thought you had a little load on it(20%). 28 degrees would be the number with 10% load. Load tables can get messed up with aftermarket MAFs also, if you are running one that matches larger injectors and haven't touched the stock computer. That's another discussion though. :)

Don
 

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Discussion Starter #6
We are going to be pulling the motor to paint the engine compartment and to work on the motor, 165 afr's, E-303 etc. While I have the heads off, I will put a degree wheel on the crank and a tdc stop on the #1 piston to determine exact TDC. (good time to degree the cam) Once I determine exact TDC, I will see if my damper lines up at TDC on the pointer to make sure the outer ring hasn't slipped. Thanks for the advise!
 

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The A9L "should" add 16* to your base timing. Also, you'll only get a "total timing" reading at WOT and under load, not sitting there with the hood popped up in the driveway. It can vary due to engine temp, air temp, engine load, etc...In other words, with the SPOUT connector hooked up, you'll never see accurate total timing with a timing light.

Total timing will be very high in light throttle cruise, low load situations. For example my old blower car used a PMS for tuning. It also had a "real time" readout of several different engine parameters, one of them being total timing...At 2000 rpm's highway cruising...I'd see as high as 52* total timing....at WOT/high load I saw 28*, which was my "actual" total timing.

Some blower guys set their timing where they want the "total" number to be, and leave the SPOUT out. This doesn't allow the ECM to make any timing changes at all, and it remains at wherever you set it. IN other words, set it at 23*, leave SPOUT out, and any rpm, any load, and any temperature, timing is 23*...

Hope this helps.
 

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Thanks for the info. I t will help get me on the right track. I still have a lot to learn.
 
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