1996 VP 5.7Gi TBI stalls and can't restart

whitesharkseeker

Petty Officer 3rd Class
Joined
Nov 8, 2010
Messages
95
This one is stumping me. Engine starts fine, runs great but will occasionally stall at idle after warmed and running and often won't restart. Engine will finally start after letting it cool down. From what I've researched one problem can be the water coolant thermometer sensor. Can this be changed out without draining the coolant? Also, I have noticed some surging at idle. Maybe IAC sticking? Engine has 4100 hours and other than these issues runs great. Any other suggestions? Has newer fuel pumps. Thank you.

Eric
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,072
Need to test and see what is keeping it from starting.
Is there 12V at the coil?
When cranking does the tachometer show 300 rpms or so?
Have you tried to get it a bit more throttle while cranking?
Measure fuel pressure
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
50,969
are you heat exchanged cooled? if not, there is no coolant, only salt water

if you are, wait until the water is cool, and you can swap sender with only loosing about an ounce of coolant.

however as AD mentioned, you should be troubleshooting prior to throwing parts at it.

what is your fuel pressure?
when it stalls, what is your fuel pressure? do you have spark?

it could be fuel system related or ignition system related or general electrical system related. until you actually troubleshoot, you are guessing.
 

whitesharkseeker

Petty Officer 3rd Class
Joined
Nov 8, 2010
Messages
95
Thank you for the responses. I have closed, freshwater cooled engine. Pressure seems to be fine at fuel pumps and only stalls occasionally when warm at idle. I think that engine coolant sensor is malfunctioning and sending signal that engine is cold to ECM when if fact it is hot. If I open throttle it starts again so must be flooding? I IAC failing. Need to look at RPM's next time I crank it.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
43,072
If I open throttle it starts again so must be flooding? I IAC failing.

Since it will start with more throttle I would suspect the IAC as the problem. That's a classic symptom of the IAC and could be its crudded up or failing. Remove and clean the tip and surface with non caustic cleaner
 
Top