Timing on 97 Merc TBI 5.7L

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Insanegtp

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Just changed dist to a MSD 8366 I did not time yet, but when I start she runs for a few seconds and dies... on the engine cover it says for timing see manual... I donot have one... any one know what I can do ??? Also when going to start I noticed it takes a few seconds for fuel to start coming out of injectors...
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

Stock dist was rusted and falling apart.... I sell MSD products and got a great deal on it...

are they bad for our purpose ???
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

According to MSD it is ok for Marine use....

and thank you for that... but is there any type of wire that must be disconnected first???
 
180shabah

180shabah

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Re: Timing on 97 Merc TBI 5.7L

but is there any type of wire that must be disconnected first???
Click to expand...
That is a question best answered by MSD.

With the TBV that used to be on your engine you had to put the distributor in base timing mode to eliminate all advance, then you could set the initial timing. Since you are no longer using that distributor, not sure if there is any special procedure.
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

Can someone explaine how to put it in base timing mode ??? There is no difference from stock to the msd dist... and I have verified this from MSD...
 
180shabah

180shabah

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Re: Timing on 97 Merc TBI 5.7L

Connect the purple/white wire to ground, then start engine and set timing in normal manner.

On the 4.3s base timing is set to 10*BTDC, you will want to confirm that for your v8. Now would be a good time to get a factory service manual. Unfortunately the free downloads are not currently available, but printed copies are alway on ebay, pretty cheap.
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

I now know the timing should be around 4-6 btdc, but I am still unsure of which wire.. / wires... where might they be located....
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

Went to local marina, bought book, read directions on installing dist, last steps states now time motor........ does not explain how.. (this is the sealoc book, not the Merc, but WAS told it was the same..) call back, explain what I was looking for.. gentleman states.. "Merc used to want that motor timed at 8 degress BTDC, now with the ethenol you should be either 0 or 2 degress, but it will be a dog, so go between 4 and 6 and make sure you run good fuel... told me to ground the purple white wire and I could find it near the shift linkage... I looked for a while, un did all the wire loom and tape.. only wire I found was coming out of dist.. so I grounded it... motor stalled.. I cut it, motor stalled, I grounded each side while attempting to re-start nothing.. I reconnected, started, and with light and ears timed the motor WITH nothing disconnected and she rans the best at 12 degress... I revved her to about 2500 (only for three or four seconds) and timing went to about 22 degrees or so, and the exhaust smelt real clean, if I retarded or advnaced it smelt either to rich or to lean...
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

Back with the same issue... and I really would like to fix this myself, not cuz of funds, or speed, but simply, I enjoy knowing the problem, and the fix... for the past month or so, she ran amazing, went in salt water... fresh water... stays in a freshwater lake 24/7... unless we pull to goto bay.. I used to be able to have 11-12 people and pull a tube and be fine... now with even 6 people, I cannot get above 10-12 mph... she doesn't go above 3500 rpms and smells real bad of fuel.... I never was able to time the motor... never was able to find the wires to disconnect for the est... PLEASE I know I am not the only person in this world with 5.7 TBI Merc..... and she the other day... she started stalling after randomly... swapped fuel filter.. emptied it and it was clean.... :(
 
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John_S

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Re: Timing on 97 Merc TBI 5.7L

Insanegtp said:
... PLEASE I know I am not the only person in this world with 5.7 TBI Merc..... :(
Click to expand...

You are probably one of only a few with 5.7TBI and MSD 8366. Probably not going to find someone with your exact combo that regularly checks posts here.

I don't think you had a T5, but regardless, you now have a MSD, which should have its own timing procedure. Also, how to adjust timing curves. The purple/white wire would have been on the T5 harness to the ICM, which, if you had it, was removed with the old distributer. An 8 degrees BTDC @ 650 rpm, seems like a reasonable starting point. I also don't know if there was any interaction between distributer and injection control, but if there was, MSD should have included how to wire/run it on the TBI.


So, has the power problem been there since '09 ? or has it gradually got worse? If the latter, it may indicate engine damage from running too advanced timing.
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

The MSD and factory dist are the same, I only put the MSD in because I run a speed and performance shop and it was available to me... the wiring does not change and it DOES NOT have its own timing, it retains the stock timing, the problem started this weekend... and my main question is how to disable the factory Electronic Sparl Timing (EST) so I can set base timing... people have told me the purple wire.. but what purple wire ? the one in back on dist... what exactly am I supposed to do with this... and I could have sworn when I installed a year ago I did something with the nutral safety switch.... I have done complete tune up again, and also check compression lowest was 120 highest was 145. 637 hours on it....
 
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Insanegtp

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Re: Timing on 97 Merc TBI 5.7L

call it what u wish.... but yes the plug that makes it so the boat will not start unless it is neutral.... I am not positve what type of ignition system I have, but I will check tonight and make sure my timing is allset... then I'll move on... thanks so much for the link to the manuals, I will be sure to let you all know what I find....
 
180shabah

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Re: Timing on 97 Merc TBI 5.7L

...call it what u wish.... but yes the plug that makes it so the boat will not start unless it is neutral....
Click to expand...

I would call that a neutral safety switch, just like you did...

BUT

It has absolutely nothing to do with your ignition, interrupts power to the starter only.
 
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John_S

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Re: Timing on 97 Merc TBI 5.7L

From #17, Section 5E:

Base Ignition Timing
In order to check or change base timing on a HEI system the ECM has to be entered into the service mode by using a scan tool or code tool. The IC module will go to base timing. The ECM will stabilize timing to allow timing adjustment. The ECM incorporates a spark control override, which allows timing to be lowered if spark knock (detonation) is encountered during normal operation. At this time, the timing can be adjusted by turning the distributor.


I believe I have seen posted a way to do it via jumper, vs tool. You will need to do some thread searching. Maybe it was a volvo post, don't remember.

Section 5E has allot of good info on how the ECM works with the fuel system and the ICM that looks like is in your distributer.


Many people confuse neutral safety switch and shift interupter. Two different things. The neutral safety switch would not have to be touched for an ignition change. The shift interupter, is a common ignition wiring that has to be done with alpha drives. It basicly grounds out the output of the sensor wheel sensor, to kill the ignition, so the drive can come out of gear.

Here is the thread. See the volvo info near end. http://forums.iboats.com/showthread.php?t=406697&highlight=base+timing+tbi
 
Don S

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Re: Timing on 97 Merc TBI 5.7L

The MSD 8366 distributor is a clone of the Delco EST distributor. The purple and white wire mentioned that you hook up to power if for a Thunderbolt V ignition system on a carbed engine.
This engine is TBI injection and must be set per the manual that sets the ECM and the distributor into timing mode.
It can not be set like you would set an EST distributor for a carbed engine. AGAIN, this is TBI, not carbed. THings are different.
 
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