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

kewlcoconut · 03-06-2006, 12:53 AM

VSV is fine. I was looking at the engine today, and saw some wires with cracked insulation or most of it missing around the wires. So I am going to fix those up by protecting them from the heat. I was told by another person that if some wires get heated up from the heatsoak, they cant function properly.

I also did what you suggested mrnickleye, and bought some fuel injector cleaner. Couldnt get the TECHRON stuff anywhere. Went to 2 Chevron gas stations and they dont even carry their own brand of fuel injector cleaner lol...strange.

mrnickleye · 03-06-2006, 02:07 AM

Maybe its a Canada thing. Perhaps they haven't approved Techron to be sold there.
Still sounds like a weird problem, and 88supraboy having it too.

ryemann32 · 03-06-2006, 03:10 AM

i would buy the stp inj cleaner the one in the black bottle i ve used it for years on all my cars and it works wonders

kewlcoconut · 03-06-2006, 07:40 PM

I noticed something else as well. I dont know if it is directly related to this problem, but maybe. When I restart the car after it is hot, I noticed that my voltage gauge is pretty low. Low as in almost 12, when it should be higher. I am running an almost new battery, new 110amp alternator and a capacitor for my system so i dont kill my battery. I checked connections and everything.

I changed my battery and alternator a while ago thinking it would solve this problem, but it didnt.

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 __________________

03-06-2006, 02:07 AM	#8
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Maybe its a Canada thing. Perhaps they haven't approved Techron to be sold there. Still sounds like a weird problem, and 88supraboy having it too. __________________ 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, 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?

03-06-2006, 12:53 AM	#7
kewlcoconut 3" Exhaust Join Date: Sep 2005 Location: Vancouver, BC Canada Posts: 157	VSV is fine. I was looking at the engine today, and saw some wires with cracked insulation or most of it missing around the wires. So I am going to fix those up by protecting them from the heat. I was told by another person that if some wires get heated up from the heatsoak, they cant function properly. I also did what you suggested mrnickleye, and bought some fuel injector cleaner. Couldnt get the TECHRON stuff anywhere. Went to 2 Chevron gas stations and they dont even carry their own brand of fuel injector cleaner lol...strange.

03-06-2006, 03:10 AM	#9
ryemann32 3" Exhaust Join Date: Nov 2005 Location: surrey bc canada Posts: 102	i live in bc to i would buy the stp inj cleaner the one in the black bottle i ve used it for years on all my cars and it works wonders

03-06-2006, 07:40 PM	#10
kewlcoconut 3" Exhaust Join Date: Sep 2005 Location: Vancouver, BC Canada Posts: 157	I noticed something else as well. I dont know if it is directly related to this problem, but maybe. When I restart the car after it is hot, I noticed that my voltage gauge is pretty low. Low as in almost 12, when it should be higher. I am running an almost new battery, new 110amp alternator and a capacitor for my system so i dont kill my battery. I checked connections and everything. I changed my battery and alternator a while ago thinking it would solve this problem, but it didnt.