I'm back with same problem flooding cylinder's again and no start 1993 3.0LX

Sorry to beat this dead horse..Carb started to drip again fouling back three cylinder's and plug's.I bought a re-built carb from "Guaranteed Carburator's" through "FLY FISH MARINE" FOR $267.00. and installed it.It's supposed to be tested and tuned for my engine pryor to shipping..Had great review's...At first all seemed ok with carb, yet engine wouldn't quite fire off and stay running.(no dripping into intake as before).Yet engine just wouldn't start.Went and got a new coil($145.00) thinking it could be bad as one of three test failed to give proper results required in manual.That didn't seem to help either. Checked coil pickup and it passed.Still getting fire to plug's and manual says that either the modual will work(fire) or it won't. Had dist. loose to try and check timing a while back when engine was still starting, so it could still be moved by hand with alittle pressure and woundered if it could have sliped some. So I tried to move it alittle one way or the other to see if engine would fire.No good there.By the way my brand new timming light quit working while I was trying to check timming that day.Don't understand why, or why I need to shunt those two white wire's on dist. but it calls for that.Also says to un-plug the shift interrupter wire's and cross connect them back togeather during his timing check.While I was playing with the timing and trying to find a point where engine would try to fire, I crossed the shift interrupter wires and shunted the two white wire's .In doing so, it seemed as if the fire was taken from the plug's because the engine quit trying to fire until I replaced the interupter wire's as normally would be.Still woundering about my compression since it was checked cold (couldn't get engine running at time)...Last check (cold) with all plug's removed and set at WOT,#1 read at 160psi and the other three pumped up to 170 psi...Also #1 is always dry and black with soot, while the other's are soaked...Also noted that a few time's engine would almost stay running, but when I let off key it would shut off and spew fuel out top of carb.Really starting to worry about compression problem's...The starter I replaced was off e-bay and was only $68.00 new..Could it not be spinning engine fast enough to build enough compression for start-up? Sorry everyone, I've looked the web over but couldn't find any other site's to bother that was as professional as you guy's to bother.Thanks again

Get the timing set to spec. Make sure the spark is good at the plug end of the wire...change the plugs to NGK BPR6EFS. Compression of 160 -170 isn't bad.

Hi guyjg, How do I get timing set to spec when it won't start? I know how to get it on compression stroke, and set it to TDC...Then remove dist. cap to see if rotor is pointing toward #1 terminal of cap.Then it's a guessing game of turning dist. a little one way or the other til it fires. Been doing that all day.Am I missing something in this process I should be doing? You figure the newest plug's are junk now that they've been soaked so many time's? Will do on that... Noticed my oil level is back up 1/4" over full cause of fuel. Plug's are fireing. That 50amp breaker wouldn't have anything to do with my problem would it? Thanks guyjg

Send me a personal message with your phone number and I will call and we can discuss issues........

If someone with a full understanding of the 4 cylinder EST ignition could chime in please.

I was reviewing the schematic for this ignition, his question about connecting the shift interuptor switch wires for base timing confused me so I took a look.

Most all other shift interuptor switch connections are, one wire goes to ground and the other to the neg side of coil or tach lead (grey wire). thus when the switch is activated the ignition is shorted to ground and interupted.......

The EST connections are, one wire goes to purple (ign on) and the other, green/white (to distributor)

My question is, if the interuptor switch is a (normally open) switch the what this suggests is when the switch is activated 12 volts is supplied to the distributor causing the interupt.

Is this true?

or is the switch a normally closed switch and when activated it stops 12 volts from reaching the distributor thus interupting it?

Anyone have first hand knowledge of this?

I have not seen enough of these to have tested this circut.

Thanks

Doug, .... no offense to you, but it sounds as though you are haphazardly throwing parts at this in hopes that one or two parts will fix the issue.
Earlier I mentioned the P of E to you (process of elimination). Meaning one item, and one item ONLY as you sort out which component is OK, and which component is not OK.
The P of E will not fail you when used methodically and systematically.

Make yourself a list of all possibilities that may be causing the problem.
Go down the list and thoroughly test each component one at a time.
Make a note of your findings, and keep the notes.

Do NOT move forward until you have confirmed one way or the other.


Or... keep throwing parts at it.
Doug, if you replace enough parts, you'll eventually get it, but it will cost you dearly.

Have you ever listened to the "Car Guys" radio talk show from New York?
When they can't help with a solution, they tell the caller to; "lift up the radiator cap, and drive another car under it!"


Doug, we're here for you, but you need to meet us half way.


.

Check the fuel pump pressure ,4-7 psi no more no less.

Check the yellow return hose for fuel.

If there is fuel in the hose the fuel pump went.

kghost, Have a look to see if some of your questions are hidden within the introduction of the Delco EST Ignition System bulletin,

http://www.boatfix.com/merc/Bullet/90/90_15.pdf

I'm pretty sure most of the switches are normally open.

During normal operation switch is (normally open) During shifting switch is (normally closed) found at the bottom (Right) of this bulletin,
http://www.boatfix.com/merc/Bullet/89/89_09.pdf


Comparing switch part numbers between 1989-1998, they all use numbers, 87-19752A3, 39670A38, 39670A28 which leads to the same new style shift/plate numbers,
http://www.ebay.com/itm/Mercruiser-..._Accessories_Gear&vxp=mtr&hash=item53f512fb63
http://www.mercruiserparts.com/bulletins/001/04//2002/EN_01.PDF

http://www.mercruiserparts.com/Show...png&inbr=1604&bnbr=170&bdesc=Shift+Components


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boat tech

I have the manuals both paper and pdf and I did summize it was a N/O switch based on the NLA of the old switch component and updates to the new switch plate and switch.

reguardless of the pdf's or maunal (but thanks for the ddis bulliten!!) I think he may have the other igniton, EST

either way none of the literature says why the switch now establishes a circut to purple (12 vdc) when activated and not to ground like all prior ignitions.

Before grounding the ignition was interupt, WHy with these two ignitions is it to +12vdc????


thanks

It lives! Replaced the wire's with the best marine set Napa sold.Got shocked the other day while testing rotor, and figured fire must be bleeding.(only thing I haven't replaced as they looked good) Still didn't fire So replaced the new fouled (multi time's) plug's with new NGK BPR6EFS (as guyjg said to do) ,and it tried to fire!Following kghost advise, I turned the dis. just a fraction more and it fired up for a few second's and stumbled ,then died.Moved dist. just a hair more and she roared to life!After the smoke cleared ,it didn't smoke any more and ideled good for air mix screw to be set at 1 1/2 turn's out from seated. Got dark on me again, but i'll fine tune that when weather clears up and do the timing check as by the manual.Everyone here has added great advise that I used to get back running and I thank you all..Special thanks to you" kghost" for taking time to call me and walk me through the timing.I was twisting that dist. like a steering wheel...lol My wife of 32 year's loves to fish and be on water.She's been sick for four year's fighting reacuring colin cancer.Getting this old pontoon going will give her alot of happiness, and I was determined to have it ready and safe by spring crappie season if I had to as Rick quoted"raise the radiator cap, and stick another engine under it...lol.....We thank you all.. Great folk's here!

Doug, good for you!

Have fun, and go catch some fish now!

Love crappie fishing...do you have big red ear sunfish there? They are fantastic fighters and great to eat. Glad for you...hope the Mrs. enjoys the boat...my prayers are with you both.