jc55

Hello guys. I have a '90 4runner with the V6. I just got my heads rebuilt with all new valves and put them back on along with new timing belt and water pump. It was running poorly when I discovered it had lost compression in a couple of cylinders...burnt exhaust valves. (That's why I got the heads redone)
I followed the manual EXACTLY through all of this.

I got it all together and timed correctly and it starts and runs. BUT, there is raw gas coming out the exhaust pipe...alot. I put a cup under the pipe to catch some, poured it onto the street and lit in on fire. It's definately raw gas.

-I immediately did a compression check. All were around 150psi(no open intake valves)
-Is this something that fuel injectors could cause? It would have to be more than one to spit out that much unburned fuel right? maybe I ruined the injectors when I had them out and wiped them off when cleaning the intake. Didn't see any dirt in the tips.
-I disconnected the little black connector on the top of the intake near the cold start injector line. Acts the same.
-could someone check my hose connections in the pic below? The book doesn't get specific. I noticed a couple of the lines had fuel and if they are in the wrong order, I was thinking I might be dumping too much in the intake.

#1 goes to cowl
#2 (2nd one down) goes to valve thing on passenger inner fender
#3 (3rd one down) goes down firewall
#4 (4th one down)goes to valve thing on passenger inner fender
#5 goes to bottom line of valve connected to pwr steering pump
#6 has a line that goes to top line of valve connected to pwr steering pump

I believe #5 and 6 are the cold start injector switch lines?

Any help is GREATLY appreciated. Too dangerous to drive. I gotta fix it myself.

Mike Murrell

Read the following URL:

http://www.mercedesshop.com/shopforu...&highlight=raw

This is a Mecedes-Benz site. I wouldn't let that be an issue. Cars are cars.

jc55

Wow Mike, thanks for posting so quickly. If that IS possible, one or two injectors holding open and dumping fuel, it would make sense since I messed with them.
I would like to get my hoses verified too just in case. Thanks!

Robinhood150

Or you could mount a sparkplug at the end of your exhaust and have fun with tailgators.

KevyWevy

ah man!!! you beat me to it robinhood! i was gonna say mount a spark plug in the tail pipe and make it into an afterburner!

jc55

Just an update in case anyone ever has this problem...It was the fuel pressure regulator. I kind of thought it was alittle too much fuel for 1 or 2 injectors.
It built too much pressure in the fuel rails and dumped 5 gallons of fuel out of the tailpipe in 10 minutes. After I changed it...$110, ran it for 10 minutes to clear the exhaust sytem of any fuel. Also about half a gallon of fuel ends up in the oilpan(yikes) so make sure you change it immediately.

fuzzmaker

I have exact same problem. Raw gas pouring out the tail pipe!! Just did the intake gasket. Everything seems fine, but it blow raw gas out the tail pipe!!! BIG TIME. I disconned some of the intake hoses and gas poured out of them! It ran a little better, but lots of white smoke poured out of pipe this time and smelled like gas. It did not stop. I finnaly just turned off the engine and cried. Could the fuel pressure regulator have a hose hooked up wrong causing over-pressure? No signal to fuel pressure regulator? Seems unlikely that PR went bad immediately after changing the intake gaskets. I think I have a hose hooked up wrong. Any help will be appreciated. I will change my oil, but sure would like to know what is wrong 1st, otherwise I'll just fill up the pan with gas again.

Thanks,

derlyn66

Hey fellas I just fixed this same problem in my 1994 3.0l 4Runner. Everyone who has had this problem has been into the engine deeper that the plenum. On the passenger side of the plenum where the cold start injector is is a fuel return line. If you hook it up to one of those big 6mm vacuum lines it will suck gallons of gas right out of your tank and dump it straight down the intake. Take care to track that line from the fuel regulator all the way to the tank. I assumed I had it right for over a week before i triple checked it. Hope this helps.

1994 V6 2X4 4Runner affectionately named "The Tumor" w/ a new motor and 326,000 miles on the chassis