Fuel Issue?

[Turbomk3]

Hey everyone! Sorry for the Long Post

I haven't posted on here but i've been a member, I know many of you are very knowledgeable on your 4runners and just like myself, we diagnose and fix our problems! But I have a weird issue.....

I am the original owner!
1999 4Runner Limited, 3.4L
266,000 Miles

Fuel Pump Replaced in December (Reason: Fuel Pump went out while driving)
Fuel Filter Replaced in December
Fuel Injectors Replaced in January (Reason: 1 Injector went bad, so i just replaced all as maintenance)
Timing Belt, Tensioner, Water Pump Replaced in October (Reason: Leaking water pump)
MAF Sensor cleaned.
Throttle Body Cleaned
No CEL or Codes

Issue
Sometimes when I start the vehicle it would take 2-3 cranks and then the engine will turn over. Yesterday was 82 degrees out, the hottest day we have had for the year here in New York! I drove the vehicle for 2 hour with no problems, I was at idle at a light and the vehicle stalled out, I tried starting it back up and 2-3 cranks the engine turned over but i sounded like it was not getting no fuel. I proceeded on my way and drove about another 1/2 hour, I came to my destination and before I put the vehicle into park it stalled again. Tried to start it again, the vehicle would crank and it would give symptoms of no fuel, like the the tank was empty (Which i filled up 2 days ago). It then started after 5 tries, about 2 minutes after that the vehicle stalled again and the same thing, it sound like i have no fuel going to the injectors and you can smell the gas. I found a spot and parked it until I came out of work. I came back to the vehicle 10 hours after and it started up with 1 crank, I brought 2 gallons of gas with me just in case....I drove to the nearest gas station and filled up but the tank was 3/4 full. I then drove 45 minutes home with no problems and today it starts and runs fine!

Any Suggestions?

Do you think the fuel pump might be going bad?
it overheated?

I am ready to give up on this Truck but I love it to much lol.


Thank you very much.

 

[Buckaroo]

Initial tank was bad fuel?

Buckaroo

 

[pauldub]

If you're smelling gas and don't have an injector or fuel rail leak, maybe you have an ignition problem. I'm not one to throw parts at a vehicle, but fresh plugs and wires might be worth a try. If it started quickly after sitting for 10 hours, it seems like you've got good fuel pressure. Is sad that Toyota didn't bother to put a fuel pressure check fitting on the fuel rail like my Cherokee has. You can get a banjo bolt adapter if you want to add a fuel pressure port. Here's a link https://www.summitracing.com/parts/rus-640700?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-russell-performance&gclid=CPX5gtHzytMCFQx7fgod3PEGeA

 

[Turbomk3]

Hey guys thanks for your input. I only use 2 gas stations around where I live and thats a BP and Sunoco.

As for the plugs and wires, I forgot to mention that they were replaced in October.

 

[Toyotayoda]

What fuel pump did you purchase? I've been in the repair business for a long time and I know from experience that the following brands are garbage and rarely last more than six months; Airtex, spectra, toughone, carquest,carter. there are probably more but these are the ones I simply will not buy. Denso have been good to me, OEM is pricy, but will last. But theres not enough info here for any kind of actual diagnosis help, other than how many parts can we throw at it. do you have a code reader that is capable of maybe a simple data list? knowing fuel trims before and during a stall event would be crucial.

 

[JayRolla]

I agree with above post. Is the pump and injectors OEM?

 

[Turbomk3]

Hey Guys, my basic scan tool cant tell me fuel trims. The replacement fuel put is denso and the injectors are GB Remanu all from Rockauto!

 

[nissanh]

You should have replaced the bad injector. The concept of "since I am there I replaced all" is good if you use OEM. The reman injectors probably garbage.

Also how old is the fuel filter? OEM?
Broken cam sensor wire due to damaged timing belt?

 

[gnarlytoes]

When it does this, is there pressure in the fuel tank when you unscrew the cap? My fj80 was acting similar and it turned out to be the 25 year old vapor canister.

 

[Turbomk3]

The fuel filter was replaced 2 weeks ago non oem. (Had this issue before changing the filter)

The cam sensor wire did break due to a damaged timing belt but that was 4 years ago. I rechecked the wire and all is in tack.

I will check if there is any pressure when I unscrew the gas cap!

I did remove both Catalytic Converters and put a straight pipe to a new muffler about 3 weeka ago, I can't afford new cats right now so that's why I did that!
Do you think that can be the problem? Restriction?

 

[nissanh]

Could the cam sensor wire break again? Check the connectivity at the wire socket near the P/S pump.

 

[Turbomk3]

Nissanh, I checked the wire 2 days ago and it was in tack. I will check the wires at the pump tomorrow. But the craziest thing just happened! I left work after posting my last post and on the way home I was driving and the truck was hesitant on the highway about 60mph, so I stepped on it and then heard a loud bang (like a gun shot) the muffler exploded apart!

 

[SCHUNTER1969]

Ok first seven things I am going to list are basic, after that it gets more involved:

1) Worth checking, was the fuel filter installed in the right direction? There is an arrow indicating correct fuel direction.

2) Check your vacuum lines. If you do not have one hooked up this could solve all your problems. Even if they are all hooked up it would be quick and easy to replace all your vacuum lines. I know some people preach about it and some people say do not do it. Check out people putting their vacuum line in a can of Seafoam. It sucks in the seafoam in and cleans out your valves. Super easy to do. I've done this three times and I just hit 260k with no adverse affects.

3) I can not stress this enough. OEM, OEM, OEM, OEM, OEM. Filters = WIX nothing else but that's just me, I have a WIX fuel filter and I use WIX air filters. Everything else OEM OEM OEM.

4) Check your ECM. You might have a loose plug. If you wanted to you could pull all the plugs, clean the contacts, and reinstall.

5) You might have a loose or failing fuse. If you have never done this it would be a good idea to pull all your fuses, clean the contacts on your fuse panels, and then install new fuses.

6) Check all your ground wires and clamps. You might have a faulty ground. You can easily remove the wires, clean the contacts on the wire and body, and reinstall. When I say all I mean ALL! Even the starter.

7) How is your battery/terminals and your alternator/terminals? If you have the slightest motor deficiency in fuel/air supply and your motor is slowly turning over this could cause the hard to start issues. If your alternator is not working this could cause the stalling out.

More involved:

Have somebody crank your 4runner (hopefully starting it) while you are under the hood. Look for any signs of fuel leakage. Around the fuel delivery rail to the spark plugs, gas lines, filter, etc. If there is a leak significant enough to prevent you from starting you would smell it as well.

Just a little operating experience from me. I replaced my fuel injectors and fudged up on one. While installing an injector I damage the one of the O-rings that's on top of the injector and goes into the rail. After installing the new injectors I took my 3rd gen for a test drive and smelled gas! When you install new injectors lubricate the O-rings before pushing the rail down to prevent this from happening, I learned the hard way.

I know this would not be the most ideal test but probably the fastest depending on your wrench turning skills. Pull all the fuel injectors out and hook everything back up with the fuel injectors out. Zip tie plastic bags or some kind of small container to the ends of the injectors and as safely as possible, turn over the motor like you are trying to start it. Compare the amount of fluid in each bag. This would give you good indication if you have a fuel delivery issue.

Another test you could do: pull your main fuel line coming into your motor bay and secure it to some kind of container. Pull the plug going to your fuel tank. Find the correct pins on the plug at your fuel tank and hook up a 12V power supply. This will turn your fuel pump on, allowing you to see the performance. You could also remove your gas tank completely and perform this test. It would probably be easier but it would prevent you from seeing how well gas is pumped through your gas lines. This would also give you the opportunity to see the contents of your gas tank.

Also if you had a fuel injector or electrical issue on one cylinder you would fill the one piston not firing. TRUST ME. That motor would be vibrating real hard. And you would be throwing several codes. So I do not believe it is isolated to just one injector/spark plug/power pack.

For you not to be getting any CEL is weird. Might want to check that bulb.

Clean your throttle body, super easy to do.

They also make spark plug testers. You pull the plug going to your spark plug and install the tool to your spark plug and the plug coming from your power pack. You turn over the motor and monitor the spark. Watch out though! If you get shocked it will hurt like a mother.... talking from experience.

A clogged cat or exhaust could cause the stalling out but I doubt it would cause the hard start issue.

Check the first 7 items I listed first and post your results.

 

[St Runner]

Too much fuel. 1 I can smell gas 2 my muffler exploded 3 wont start when warm but starts fine after sitting for 10 hours. All symptoms of too rich fuel mixture. You need to get a code reader and find out what is going on. If you don't have a check engine light and you don't have a catalytic converter something is not at all right

 

[Turbomk3]

Ok I got CEL, codes
P1135- Air-fuel Sensor heater circuit response malfunction.
P0171- system too lean bank 1

I took the truck back to the shop who installed the straight pipe with the new muffler and he scanned the vehicle, he said that the muffler blew apart because of the front o2 sensor is bad which is the air-fuel sensor.

 

[SCHUNTER1969]

Replace your MAF sensor. Not clean it, replace it. If you just recently cleaned it and its already throwing a code the sensor has failed.

Replace your bank 1 O2 sensor. This is the important one that the ECM uses. The bank 2 O2 sensor is not important.

Muffler blew apart?! Was it made out of card board? I do not care if you just shot NOS down your intake, the muffler should not fall apart.

 

[Turbomk3]

Yeah it just blew apart. It is so weird.....

I will replace both sensors and give an update!

Thank you everyone.

 

[TheDurk]

Replace your MAF sensor. Not clean it, replace it. If you just recently cleaned it and its already throwing a code the sensor has failed.

Replace your bank 1 O2 sensor. This is the important one that the ECM uses. The bank 2 O2 sensor is not important.

Muffler blew apart?! Was it made out of card board? I do not care if you just shot NOS down your intake, the muffler should not fall apart.

My BIL did it once. Couldn't start his beater old C10 Chevy pickup up in the mountains (no cats) and ran the battery down. Decided he could start it coasting down the rocky mountain road. No spark, so he managed to fill that muffler up with gas until something made that sucker explode. Peeled apart like a sardine can. Sounded like a bomb went off.

Only time I've ever seen that. P.S. He was an engineer.

 

[Turbomk3]

Update

Hey Guys, I replaced the o2 sensor and MAF sensor 5 days ago and the CEL has not come back on. There are no codes and readiness is ok. Replaced all with Denso Parts. So far I haven't had the stalling issue. Thanks for all the help.

Here is a pick of how the exhaust blew up.

 

[JWaldz]

Glad you got it fixed..

Considering the extent of the muffler "blow-out", I'm surprised you couldn't simply tell something was up from the exhaust sounds you were probably getting.