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View Full Version : Problem cranking Prostar when hot !!!


Debo
06-21-2010, 12:53 PM
I have a 97 Prostar that runs great and cranks up fine when cold but once it gets hot it takes forever to get started, sometimes wont crank until cold. Anyone have any suggestions or fixes to the problem

oxberger
06-21-2010, 01:34 PM
Debo, welcome to the forum. It could be several issues. The first things that come to mind are vapor lock or it may be a small crack in a vacuum line that reseals itself once cooled down. Is your engine carb of fuel injected? mrmastercraft has had some good insight to issues like this, so hopefully he'll come along and help out. By the way which engine do you have?

rwassman
06-21-2010, 05:42 PM
Classic starter problems. Try an new starter and see if that helps.

oxberger
06-22-2010, 11:31 AM
Classic starter problems. Try an new starter and see if that helps.

Didn't even think of this, but that's a good place to look at too. Before replacing the starter though check your battery cables going to and from it to make sure they're not cracked or corroded and that they're making a good connection. That may be an issue too.

Debo
06-24-2010, 11:15 PM
Oxberger and others thanks for the replies, im not much of a mechanic but im about 4 hrs away from a reputible dealer. Anyway its a 350 efi 5.7ltr

thatsmrmastercraft
06-25-2010, 01:57 AM
It sounds like you are dealing with some high resistance made worse by heat.

I would first clean the connections at the battery, ground at the block, solenoid and starter. Remove them and clean with a wire brush. If that doesn't take care of the problem I would remove the starter and take it to a reputable auto parts store, or better yet a starter rebuilder.

Likely this will lead you to the source of your problem.

Debo
06-25-2010, 08:33 AM
Thanks Mr Mastercraft. The engine will turn over but it just wont fire. You think that could still be connection or starter problems ? Sorry for my mechanical ignorance.

duffcam
06-25-2010, 09:10 AM
quote "The engine will turn over but it just wont fire"

it's not the starter then. do you operate your bilge blower at low/idle speeds (as is reccommended by MC)? you might even try leaving the engine cover open while you are sitting still, see if it's a cooling issue or a heat soaked fuel or ignition issue. my son had the same issue, we also increased the size of the rear vent on the engine cover

JimN
06-25-2010, 09:21 AM
Debo, welcome to the forum. It could be several issues. The first things that come to mind are vapor lock or it may be a small crack in a vacuum line that reseals itself once cooled down. Is your engine carb of fuel injected? mrmastercraft has had some good insight to issues like this, so hopefully he'll come along and help out. By the way which engine do you have?

All MC motors since '94 have been injected.

JimN
06-25-2010, 09:27 AM
FYI- 'crank' means "cause rotation" and 'start', or 'fire' is the correct word for the problem in this thread. This motor cranks.

High air temperature? Was it run hard immediately prior to shutting it off? If it's the first, open the motor box a few minutes before cranking it next time. You can also turn the bilge blower on for a few minutes, as recommended. If it's the latter, idle a little longer before shutting it off- not only will the motor's temperature be higher but fuel may drip from the injectors because of the increased line pressure that remains after the motor shuts off.

What else can you tell us about how it is run, maintained and any recent repairs?

Davo
06-25-2010, 09:41 AM
I had the same issues early on with a brand new X-5 in '02. Same engine. The dealer couldn't replicate the issue at the shop = duh. I digress. I found that doing what duffcam suggests cured the problem and concluded it was "heat soaked fuel" issue aka vapor lock. Even just running the blower can help keep the engine compartment cooler, but I oftem times will prop the cover open for a bit when I plan to sit for a while after running at full temp.

Increasing the size of the rear vent on the cover sounds like a good idea as long as it doesn't pump hot air to the back seat area. I have also heard of guys wrapping the fuel lines with some type of heat resistant insulation.

I could probably stand to clean some of the connections that mrmc spoke of...and my starter hiccuped the other day...it's 8 years old though and been running like a champ.

Davo
06-25-2010, 09:45 AM
.......open the motor box a few minutes before cranking it next time.........

This always cured the issue for me even if I didn't do anything else. And you know it's hot down here.

Jesus_Freak
06-25-2010, 12:44 PM
I have a 97 Prostar that runs great and cranks up fine when cold but once it gets hot it takes forever to get started, sometimes wont crank until cold. Anyone have any suggestions or fixes to the problem


Welcome. See if this is of any value to you: http://www.mastercraft.com/teamtalk/showthread.php?t=17522

Debo
06-25-2010, 02:27 PM
No recent repairs. No consistancy in it not firing other than the engine being hot. It has failed to fire after wakeboarding sessions and after cruising around lake. I have not turned on blower at idle speeds prior to turning off. Sometimes it takes a couple of hours to cool enough to fire