Vapor Lock?

kewlcoconut · 03-04-2006, 08:41 PM

Alright, so I got my car back from my blown HG. It runs amazing, I love it so much

. But I still have a problem that I have had for about 1yr. The car has troubles or dies when restarting hot after about 10-15mins of sitting. Could it be vapor lock in the fuel lines?? if so, how would i resolve this? Heat shields around the fuel lines?

mrnickleye · 03-05-2006, 01:01 AM

These cars don't get 'vapor lock'. They do get carbon build up on the back sides of the intake valves. The official fix, back in the day, from Toyota was to remove the head and de-carbonize the valves.

When your head was off, did you have a valve job done ??

Your problem can also be a fuel system that does not hold residual pressure in the lines when the engine is off. In other words, the pressure bleeds down. This can be caused by 1 or more dirty injectors.

The first thing I would do is get 2 bottles of Techron fuel injector cleaner, for the fuel tank. Walmart and all the parts stores carry it. Independent tests have shown it to be the best "YOU" can buy. (I have stuff 10x stronger down at the shop).

I would put a bottle in about 1/2 a tank and go for a long "Sunday" drive. Then add another bottle and fill the tank up, and drive normally.

88Supraboy · 03-05-2006, 03:29 AM

I get the same problem! if my car sits for 10-15 min. after shuting down, then i restart, it bounces from like 300rpm and 600rpm, i can keep running and it only lasts for about 20 seconds, but very werid. If i restart it before or after the 10-15 min. period its fine.

kewlcoconut · 03-05-2006, 03:41 AM

ok, well i guess its not vapor lock lol. when the head was off, they changed all the valve stems and did basically the whole nine yards on the engine. I had a full gasket kit, so I told them to replace whatever they came across with a new gasket in the kit.
I use fuel injector cleaner once in a while, but it never seems to really help with this problem. I will buy the techron stuff and do what you said.

lets just say fuel injector cleaner doesnt solve the problem. then am i looking at dirty injectors? or major carbon build up in the intake valves?

mrnickleye · 03-05-2006, 06:14 AM

Since you had a valve job done, they would have cleaned the valves, so I doubt that is the problem. Perhaps the injectors are dirty.

I would perform a fuel pressure test, and a leak down test. If an injector(s) is dirty, it may get stuck open when the engine is off, and allow the fuel pressure to bleed off.

Our cars fuel pumps don't charge the system in the 'on' position before starting, like some other cars. So it might take a few more cranks to build the fuel pressure up, and allow the car to start.

Also...it could possibly be an electrical problem. Either a connector, or even an electronic component that gets problem when it reaches a certain temperature.

Believe me, I've seen some very weird things in vehicle electronics.

Strannik · 03-05-2006, 08:29 AM

check your VSV valve
its under intake manifold, front side of the engine

03-04-2006, 08:41 PM	#1
kewlcoconut 3" Exhaust Join Date: Sep 2005 Location: Vancouver, BC Canada Posts: 157	Vapor Lock? Alright, so I got my car back from my blown HG. It runs amazing, I love it so much . But I still have a problem that I have had for about 1yr. The car has troubles or dies when restarting hot after about 10-15mins of sitting. Could it be vapor lock in the fuel lines?? if so, how would i resolve this? Heat shields around the fuel lines?

03-05-2006, 01:01 AM	#2
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	These cars don't get 'vapor lock'. They do get carbon build up on the back sides of the intake valves. The official fix, back in the day, from Toyota was to remove the head and de-carbonize the valves. When your head was off, did you have a valve job done ?? Your problem can also be a fuel system that does not hold residual pressure in the lines when the engine is off. In other words, the pressure bleeds down. This can be caused by 1 or more dirty injectors. The first thing I would do is get 2 bottles of Techron fuel injector cleaner, for the fuel tank. Walmart and all the parts stores carry it. Independent tests have shown it to be the best "YOU" can buy. (I have stuff 10x stronger down at the shop). I would put a bottle in about 1/2 a tank and go for a long "Sunday" drive. Then add another bottle and fill the tank up, and drive normally. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.

03-05-2006, 06:14 AM	#5
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Could be electrical Since you had a valve job done, they would have cleaned the valves, so I doubt that is the problem. Perhaps the injectors are dirty. I would perform a fuel pressure test, and a leak down test. If an injector(s) is dirty, it may get stuck open when the engine is off, and allow the fuel pressure to bleed off. Our cars fuel pumps don't charge the system in the 'on' position before starting, like some other cars. So it might take a few more cranks to build the fuel pressure up, and allow the car to start. Also...it could possibly be an electrical problem. Either a connector, or even an electronic component that gets problem when it reaches a certain temperature. Believe me, I've seen some very weird things in vehicle electronics. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.

03-05-2006, 08:29 AM	#6
Strannik 3" Exhaust Join Date: Dec 2004 Posts: 51	check your VSV valve its under intake manifold, front side of the engine __________________

03-05-2006, 03:29 AM	#3
88Supraboy 3" Exhaust Join Date: Oct 2005 Location: Michigan Posts: 55	I get the same problem! if my car sits for 10-15 min. after shuting down, then i restart, it bounces from like 300rpm and 600rpm, i can keep running and it only lasts for about 20 seconds, but very werid. If i restart it before or after the 10-15 min. period its fine.

03-05-2006, 03:41 AM	#4
kewlcoconut 3" Exhaust Join Date: Sep 2005 Location: Vancouver, BC Canada Posts: 157	ok, well i guess its not vapor lock lol. when the head was off, they changed all the valve stems and did basically the whole nine yards on the engine. I had a full gasket kit, so I told them to replace whatever they came across with a new gasket in the kit. I use fuel injector cleaner once in a while, but it never seems to really help with this problem. I will buy the techron stuff and do what you said. lets just say fuel injector cleaner doesnt solve the problem. then am i looking at dirty injectors? or major carbon build up in the intake valves?