Engine shutting off-stalling
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=30744
Printed Date: October-08-2024 at 9:16pm
Topic: Engine shutting off-stalling
Posted By: Nauti87
Subject: Engine shutting off-stalling
Date Posted: July-14-2013 at 10:06pm
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'87 351 PCM, EI of some brand (can't tell)fresh rebuild on the carb, runs great! When the boat is warming up, either on the trailer or in the water, it starts right up, but it will die probably 5 times (even at a high idle 1200rpm). It's not fuel related, it's like the ignition was shut off. All I've had time to do is have a test light on the coil, never loses 12v. Also had a spark checker on the plug. When I get a chance I'll test the signal to the coil. I've done some searching on here but haven't seen the same "issue". Just figured I would throw this out there and see if anyone has had the same issue. Thanks. |
Replies:
Posted By: backfoot100
Date Posted: July-15-2013 at 12:46pm
| How does it run after it's been wormed up? |
Posted By: Nauti87
Date Posted: July-15-2013 at 2:20pm
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Foot, It runs great after it throws it's temper tantrum. I actualy had a car years ago that had a distributor loose ground occasionally. But I don't think that would do it with an optical pick up. |
Posted By: backfoot100
Date Posted: July-15-2013 at 2:56pm
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Have you checked the choke? Sounds like the choke might be too far open when it's cold. Common occurance to have the bimetal spring in the choke just be worn out or not have the full range of motion it should. When it's cold, remove the flame arrestor and look at the choke plate. It should only have 1/16"-1/8" gap from the choke horn. Any more than that and you'll have a terrible time keeping it running until it's warmed up. If it's not properly adjusted, loosen the three screws around the edge of the black choke housing and rotate the choke housing to adjust the choke plate gap. Then turn the key on but don't start it. The choke plate should start to open when it gets energized from the ignition switch. It should be completely straight up and down in the choke horn in about a minute. Maybe a little longer. If the choke doesn't have the full range of motion or can't be properly adjusted, time to replace it. |
Posted By: TRBenj
Date Posted: July-15-2013 at 3:08pm
Im not so sure, Eddie... my 2 best starting boats either have the choke disconnected or milled off entirely. Im not convinced theyre good for much at all, at least at the moderate temperatures I tend to boat in. Now HW may appreciate his, since he skis until the water freezes! I have seen some EI modules do some very strange things, and I would wager a guess that is what he's dealing with. I had one that would lose spark at ~1500rpm... ran great at idle and if you go WOT out of the hole, would go great at 2k rpm on up. Easing the throttle up (or down) would result in an instant shut-down just off idle speed. So these things can be a little glitchy at times. |
backfoot100 wrote:Posted By: Nauti87
Date Posted: July-15-2013 at 4:57pm
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I just had the carb rebuilt (first one I've ever sent out, but they sonic cleaned it and that's what it needed) and I set the choke. It seems to be loosing signal or power intermittantly. I'll be checking it out sometime this week. |
Posted By: backfoot100
Date Posted: July-15-2013 at 5:38pm
Interesting. Haven't heard of a good starting carbed engine cold without a choke (at least in standard holley configuration). Not saying they don't exist. I would be verey ineterested knowing if you had to do anything different to them after removing the choke. Could be some good conversation over a couple cold ones sometime. My boat is terribly cold blooded until it warms up but that's only for a minute. Always has been. Before and after the engine build as well as a couple different carb rebuilds. It was really bad several years ago when I realized the choke was shot and I still lived in WI. Changing it helped immensely. The EI doing weird stuff I can totally believe. |
Posted By: TRBenj
Date Posted: July-16-2013 at 8:22am
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I wish I could explain why, but I tuned the 2 nice starters (skier and bfn) the same as the one that is cold blooded ('90). The first 2 never had functional chokes, so I can't compare the difference before/after. A few throttle pumps and they'll both about run at idle as soon as they start... The other wont let me run it below 1000rpm until the temp gauge is a bit over 100deg. Very strange. What I really need is Tom (Gottaski) to give everything a once over! ------------- |
Posted By: backfoot100
Date Posted: July-16-2013 at 11:53am
Mine isn't quite that bad. A couple pumps and it fires right up and I need to keep it above 1000RPM for about 20-30 sec. Then I can ease it down to idle....and I mean ease it down. The whole process takes 45sec. to a minute. then it's good to go. Certainly don't have to wait until it gets over 100. When the choke was bad, trying to keep it running for that first minute was a real lesson in futility. Yes, Tom could make some nice extra cash doing some fine tuning on all our carbs. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: Nauti87
Date Posted: July-20-2013 at 11:19pm
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UPDATE, I put my meter on the + side of the coil and the dist as a ground, 12.4 volts when running, when it dies I still have voltage. 13.4 at the battery when running. I put my meter on the + & - of the coil while running 4.3 volts, when it dies it goes to 0. That tells me that the EI is dying out. I think it would be an old Prestolite. What are your thoughts? |
Posted By: Nauti87
Date Posted: August-03-2013 at 9:51pm
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I replace the old Prestolite module with a Mallory module, so far so good! ------------- 1987 SN 2001 Barn Find aka "Nauti" (sold sadly) 1988 MC Anniversary Prostar 190 |