Delco EST wiring questions...

[Coryb]

I am installing the Delco voyager distributor in my 1990 3.0 merc and I want to make sure that I get it right. The directions seem simple enough but I want to make sure of a couple of things. 1) I have 2 purple wires to the + side of old coil, one solid purple and one purple/yellow. The solid purple reads around 12.3 v and the other (which I think goes to the starter) doesn't read anything that makes sense. Is it possible that I don't have the resistor to worry about since I'm getting full voltage? Everything I've read says that it should and it needs to be bypassed. 2) Is there any diagrams available in the forums that would show how to wire up the shift interrupt correctly. I can't see how its done in the instructions that came with the distributor because the print is way to dark. 3) The instructions also say not to use an old school strobe timing light because of accuracy issues, is that true? I ask only because they are expensive and no one around my area rents them. Dont want to buy one to use only once.

 

[Fishermark]

The old shift interrupt wiring grounded out the coil. The new system requires the 12 volts instead of a ground. You will need to have one wire of the switch go the coil and the other side of the switch go to a switched 12v connection. Like this:

 

[Coryb]

That definitely helps. There is a connection terminal for the switch wiring right beside the interrupt switch. Can I splice onto the switch there and just cap off the other two ends that the switch wiring was connected to?

 

[Rick Stephens]

Delco warnings about timing lights is some serious CYA on their part - they wouldn't want you to use anything as gauche as an older timing light (/sarcasm). They want you to have an advance type light, but if you know how to use a piece of chalk, your older regular light works perfectly and indicates on the timing plate what the advance is. Silly of them to insist you can't time your engine to 2 BTDC or whatever without a fancier timing light.

If you have 12V to the purple wire you don't have a resistor.

When the starter is cranking the one from there gets power as well. (edit - normally that bypasses the resistor power - so a little confused why you have no resistor and a bypass wire both)

Rick

 

[bruceb58]

Measure the voltage at the coil with the points closed. If the points are open, you will always measure battery voltage since there is no current flowing.

If you don't have a points type distributor right now, you won't have a resistor.

BTW, I thought 1990 engines had EST already. Your engine may be older.

 

[Coryb]

Measure the voltage at the coil with the points closed. If the points are open, you will always measure battery voltage since there is no current flowing.

If you don't have a points type distributor right now, you won't have a resistor.

BTW, I thought 1990 engines had EST already. Your engine may be older.

I did have points but just put the est in. As far as I know it's the original engine to the boat. 90 sea ray 170 BR. I think I've read that mercuiser started using the est in 91 and newer boats?

 

[bruceb58]

According to what I looked up, up through 89 had the points. Not sure it really matters as Mercruiser really goes by serial numbers anyway and not by year. Not uncommon for a 90 boat to have a slightly older engine. The Volvo in my boat is that way. It is a 98 but has an engine that really has the model number associated with a 97.

 

[Coryb]

Well I managed to get the EST hooked up and timed. The instructions that came with the new distributor say to be at 1* BTDC but flame arrester cover says 8*. Which should I go by? Everything seemed to be running ok at first and my dead spot was gone, but it doesn't want to stay running very well now. When I rev the engine and pull throttle back down it wants to stall out. And to top it off now it wont turn over at all. Like there isn't even a battery hooked up, nothing. Battery still has full charge. Could it be solenoid or something like that?

 

[Rick Stephens]

Use the Delco setting. It is a 'base timing' setting where the advance is turned off. Once the base timing connector is removed the ignition will advance to around 8 BTDC.

RIck

 

[Coryb]

Use the Delco setting. It is a 'base timing' setting where the advance is turned off. Once the base timing connector is removed the ignition will advance to around 8 BTDC.

RIck

Ok. Thanks

 

[Coryb]

I found the reason I'm getting nothing when I try to start the engine. The 10 amp ignition fuse under the dash blew. Has anyone had this issue after installing the est? Does it mean that something may not be wired right?

 

[alldodge]

I found the reason I'm getting nothing when I try to start the engine. The 10 amp ignition fuse under the dash blew. Has anyone had this issue after installing the est? Does it mean that something may not be wired right?

It would with a 10 AMP, it should be a 20 AMP

 

[bruceb58]

Did you change how your shift switch is wired? It can no longer be grounding the coil. Needs to supply 12V. See FisherMarks post#2

 

[Coryb]

Well it seems to installed correctly and is running much better. I still have the dreaded dead spot in throttle though. I took the carb back off and noticed that the accel pump linkage has a little play before it starts to pump the shot of fuel. It seems no matter what I do I can't get rid of the play. Might need to purchase new accel pump components to get rid of the play or just deal giving an extra pump on throttle when I want to take off. Any thoughts?

 

[alldodge]

I leaning more toward the pump needs replaced or the pump bore has gotten bigger and does not allow for a full pump. there will always be a bit of play, and most cases when a new pump does not fix the issue is the bore is out or round

 

[Coryb]

I leaning more toward the pump needs replaced or the pump bore has gotten bigger and does not allow for a full pump. there will always be a bit of play, and most cases when a new pump does not fix the issue is the bore is out or round

I did a rebuild a couple months ago and replaced the pump so it's new. I didn't realize the well could get out-of-round. When manually moving the pump up and down its basically air tight, it's just the first bit of throttle movement that doesn't seem to move the pump

 

[alldodge]

Have you checked compression?

 

[Coryb]

Have you checked compression?

I have not checked compression.

 

[alldodge]

Then your problem may not be the pump, it may just be that your idle is adjusted to lean. This is caused when the accelerator pump puts fuel down the carb throttle plate is closed to much. The fuel enters and there is not enough air to carry the fuel to the cylinders so it puddles in the intake. Once the engine manages to pick up speed the air moves all the puddle gas and burns it then things are good.

Try opening the mixer screws a bit more and see what happens

 

[Coryb]

I'll give that a shot. ive got it about 2 turns out now because that's where I had to put it to get it to idle good. How much is to far? Don't want to mask an issue