PDA

View Full Version : idle after cruise = stall???



KerrLake
08-18-2006, 09:27 PM
I'm just taking my 1st cruises on the 86 z25. When it first starts up and cruises for a good while everything is fine. After a 15 min or more crusie at approx. 40 mph, when I bring it back to idle it wants to stall. I can get it to start back up and it runs, but has an occaisonal miss and sometimes stalls. I can smell what seems to be un burned gas and when it started after a stall there was some black "stuff" in the water from the exhaust. Any suggestions??? Also there is a green wire coming out of the wiring harness which is not attached to anything. I'll attach a picture. I'm trying to learn to work on the boat but am a novice. The engine was removed and reinstalled before I took ownership of the boat. The picture of the engine is before it was removed, but I can't see where the green wire goes. Thanks for any help.

Brian

KerrLake
08-18-2006, 09:36 PM
I'm having trouble attaching pics!!

farmer tx
08-18-2006, 09:51 PM
Try resizing your pics.

mrfixxall
08-19-2006, 11:35 AM
I'm just taking my 1st cruises on the 86 z25. When it first starts up and cruises for a good while everything is fine. After a 15 min or more crusie at approx. 40 mph, when I bring it back to idle it wants to stall. I can get it to start back up and it runs, but has an occaisonal miss and sometimes stalls. I can smell what seems to be un burned gas and when it started after a stall there was some black "stuff" in the water from the exhaust. Any suggestions??? Also there is a green wire coming out of the wiring harness which is not attached to anything. I'll attach a picture. I'm trying to learn to work on the boat but am a novice. The engine was removed and reinstalled before I took ownership of the boat. The picture of the engine is before it was removed, but I can't see where the green wire goes. Thanks for any help.
Brian

Whats your power plant? carb or efi?

Donziweasel
08-19-2006, 12:27 PM
What elevation are you at? Black exhuast smoke, smell of unburned fuel sounds like you are running way rich at idle. Like Mr.Fixall says, carb or efi?

KerrLake
08-19-2006, 02:31 PM
454 carb at 300 ft. I got an engine pic to come up.

Thanks.

mrfixxall
08-19-2006, 03:38 PM
454 carb at 300 ft. I got an engine pic to come up.
Thanks.


First thing i would check is your choke,sounds like its closing...See if the rod is still attached,they fall off or the choke heater is shot...

KerrLake
08-20-2006, 08:17 AM
I checked the choke before I started the engine and several times while we were out. I did a 1200 rpm cruise for about 30 min before I started to have any miss. Could the loose green wire have something to do with this? Also noticed that while cruising if I have on the cabin lights or trim the drive the low voltage light lights up, then goes back out. What should I check next???

Thanks,
Brian

gold-n-rod
08-20-2006, 03:26 PM
I had the exact same trouble last summer with the 454 in my "big" boat (see sig). A rebuild of the carb solved all my troubles.

PM me if you need a recommendation for a rebuilder.

mrfixxall
08-20-2006, 08:14 PM
First thing i would check is your choke,sounds like its closing...See if the rod is still attached,they fall off or the choke heater is shot...

yes if the green wire is the choke wire but it looks like your choke is mechanical......i just remembered somthing,,check the tube coming from the fuel pump(greenish or yellow)to the flame arrestor..
the diaphram may have reptured and is dumping gas into the carb..

KerrLake
08-21-2006, 03:34 PM
I found a loose ground wire yesterday to one of the batteries. The boat seems to do better. However, cruising at idle or just above it stalled. It is a mechanical choke and it seems to be working properly. Could it just be running to rich? If I do a high speed run it seems to happen more afterwards. When it is cold and sometimes for any hour or so it won't stall since I fixed the ground. As for the mystery wire any suggestions on how to figure out what it may go to???

Brian

joseph m. hahnl
08-21-2006, 04:29 PM
white and green goes to the distributor. green or green with white goes to the power trim depending if you have a single or duel solonoid. the wire in the picture looks replaced it also looks like it is going to the distributor. . check to see that there are 3 wires going to the distributor one should be white red and the other 2 as we discussed is white green. one goes to the ignition amplifier and the other goes to the shift cutout switch When in doubt trace the wire to its beginning .


you really need to find out if that is a patched in wire


What make of Carb? it most likely only needs the idle mixture screws adjusted.
general rule "with the throttle plate closed and the linkage disconected" turn them all the way in till just snug. Turn them back out 1 1/2 turns ,
Do not over tighten them going in you can damge the needle and there seats very easily. better to use your fingers to turn them in if possible



joe

KerrLake
08-22-2006, 09:08 PM
Thanks Joe-I had a few minutes tonight to go down to the dock. The green wire goes into the main harness that goes towards the front of the boat, I guess the instrument panel. I have noticed that when I adjust the drive the low voltage light has a dim glow, or turn on the cabin lights. I didn't have time before it got dark to take the instrument panel off to see where the green wire goes. If it goes to the low voltage indicator where would the green wire go on the engine?? Does that sound reasonable?

Brian