Ford Mustang Forum banner

Status
Not open for further replies.
1 - 7 of 7 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
My 1989 GT 5.0 seems to always vapor lock (or at least that is what I think is happening) when the temp outside is around 85 or above. It will die after about 20 minutes of driving, then start back up after about a half an hour or so. The exhaust is an H pipe with flowmasters and nothing past that. I tried insulating the fuel pump and lines but that doesn't seem to help. If I put pipes on it all the way back would that help? Or does anyone else have any other suggestions?

Thanks

Mike
 

·
Super Moderator
Joined
·
39,993 Posts
welcome to the site,enjoy!!!!.....do you have turndowns on your exhaust?,or is it shooting at the tank?
 

·
Registered
Joined
·
27 Posts
Do you know for a fact that it dies from a lack of fuel? Sounds more like an electrical problem. In my opinion it would be almost impossible to be "vapor lock". Vapr lock used to happen to older cars when it was hot outside and engine temps were high. An actual vapor bubble would form in the fuel line. With high pressure efi cars, any bubbles or air would be pushed though so fast, you probably wouldn't even feel a hickup.

If it's possible, next time it dies, ckeck for fuel at the schrader valve in-line. (should be right behind altenator) Just watch out for spraying fuel!
If there is fuel, check for spark.
I have seen coils "open up" when hot, killing spark.
Good luck, hopefully it's not to much of a pain to find.
 

·
Registered
Joined
·
579 Posts
Has this car been converted to a Carb because if your Fuel Injected and the return line is not clogged I don't see how a FI car can vapor lock. I would say impossible to vapor lock.
 

·
Registered
Joined
·
651 Posts
Sounds to me like the fuel pump might be bad. After driving during the hot day the fuel pump will overheat and shut down. After you give it some time to rest, like 20 mins, it has cooled a little bit and works again. To confirm this do what EACM06 said and check for fuel. Just my 2 cents...
 

·
Registered
Joined
·
46,020 Posts
I too am thinking more like the fuel pump. Vapor lock happened on the older cars, and it's never heard of on an EFI setup.
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top