Kiroshu

i'm considering sea foaming it again any suggestions?

ahickman

Kiroshu, when you remove the fuel cap do you hear a whooshing sound? If so, is it sucking air in or blowing air out? This would help determine which part of the fuel return/delivery to troubleshoot next.

scope103

1. When there is a vacuum in the fuel tank (e.g., from pumping fuel out), the check valve in both the cap and the in the evap canister should open to allow air into the tank (vapors in the tank should not leave through the check valve in the cap.) Which makes it sound like a problem with the cap.

2. Are you sure you've got a) correct timing and b) working ignition advance? Since you're getting hesitation on acceleration without load, that sounds more like timing than a fuel problem (the fuel demand doesn't go up that fast when you accelerate without any load). Using your timing light, verify that the ignition timing is set to the label on the hood, and that it advances as you run up the throttle.

Kiroshu

UPDATE! I do here a sound of air when the cap is off but i 'm not sure if its sucking or blowing i'll check here soon. Oh i just cleaned coolant temp sensor and put "another" new gas cap on which is the 3rd one and reset computer by unhooking neg bat termial and started it up AND THERES NOW A CHECK ENGINE LIGHT! It runs exact same as it always had but with a light and also new cap again theres still stumbling of motor. There was no light before the whole time until now.... If i sit at idle and rev it to about 2000 rpms and hold it exact steady theres a surge. So it does it under NO load as well. i've not messed with the timming ever on the truck. I did try and look for notch on crank pully with timing light but could not see it it was not there....is that bad? or is it off very bad? I have to head to work for 6 hours and i'll be back keep me posted guys i'm trippin over this!!!!!

scope103

You may be getting somewhere. If you've got a bunch of things going on, it makes sense to fix the easiest things first. Find the timing mark with the engine off; put a wrench on the crank bolt and turn the crank until you find it. Then fill in the mark with paint, wite-out or chalk to make it easier to see. When you get that done, make sure the timing is set correctly (or figure out why you can't set it.)

I'm not aware of any codes that can be set just by having the timing off (even way off), but you'll need to find out what code you're getting. Check the manual for how to read the codes; it's not hard.

Once you know what's going on with the timing, and what CEL code you're getting, you can address your stumbling problem without so much guessing.

Kiroshu

UPDATE!!!!! So i just got home from work.. holy cow get this. I was leaving work to go to my truck i got in tried to start it. it ran for 2 secs and cut off....i was like wtf? tried again same thing ran for a sec and shut off...i was like omg another problem.... so i thought for a min... and realized theres only one thing that i knew off that could cuase this. FUEL PUMP!!!!!!!!!!!!! I turned the key on opened up the inspection plate under back seat and it WAS NOT RUNNING!!!!!! THAT DANG FUEL PUMP WAS PROBABLY THE PROB THE WHOLE TIME!!! But anyway. I got my hammer out and beat on that dang pump and after hitting it about 30 times it came on and the truck started. Well i didn't know how long it would last so i had someone follow me home. It got me home good but stumbling like a moefoe. I still have that check engine light on as well... not sure what that is.... fuel pump is going to be changed tomarrow and imma reset ECU again to see if anything changes i'll keep ya posted....

scope103

It's not supposed to be running. It comes on when you CRANK the engine, and then continues to run when the switch in the Volume Air Flow meter closes due to sensing air flow. This way, if the engine dies, the fuel pump stops with it (what would YOU want to happen in an accident ...). In other words, KeyOn EngineOff means the pump is not running.

You can check that by connecting the B+ and FP terminals on the diagnostic connector (with keyon); that overrides the VAF and runs the fuel pump. Easier than hitting it with a hammer ....

I know this is frustrating (particularly when you get stuck somewhere), and you want to find "the" answer, but I think you'll be more successful if you try to solve your problems step by step.

Kiroshu

UPDATE!!! yes guy above me i was not thinking and yea it does not run while motor off. but as i tried to crank it i still heard no pump and engine was not starting. but after a few trys the fuel pump kicked on and so did the motor. Ok so i found out alot of stuff today holy cow it was not even the fuel pump and possibley never fuel related. Ok soi thought the pump was bad and ofcourse i bought a new one a new bosch one with a lifetime warranty. It was installed i turned the engine over....STILL NOT START! i tired about 4 times and the pump was not comming on...... so i'm like wtf.... it would not start at all... i'm thinking...i know its a good pump....new fuel filter....gas cap.....no leaks...... so i thought for while.... i checked all fuses....fuses were all good.... so i thought well dang it might not be getting voltage back to the pump.... so i tested the connector with a multimeter and testlight..... NO VOLTAGE WAS GETTING BACK TO THE FUEL PUMP!!! Even as i turned the engine over no voltage...... soo...this was a big step cause i never thought this was an issue... WELL NOW IT IS!!! ok so after 5 and a half hours of checking all the relays fuses and shorts in wires.... i found it to the the "Circuit Opening Relay" (this is also called the fuel pump relay) was bad on it and i swapped it out on my dads 1990 4runner, the relay was the same and IT WORKED it started the truck!!!!. Ok so i figured out why the pump was not getting voltage!!! Sweet!! Ok now to address the other problem..... it still ahs my stumbling and surging problem AND a check engine light!!! Ok so i pulled the code for the light and it read code 4...which in my book was Thermo sensor, thermo switch, or computer....... so i don't evenk now wtf that is..... thermo... sensor? any tips? anyway thats that but i was messin around some more and FOUND A FUEL LINE LEAKING!!!!!! Could leaking lines cause stumbling and hesitaition?!?!?!? and good idle?!?! So i'm going to replace the leaking line tomarrow and see if i can do anything about the code.... any other input will be appreciated!!!!!!

Kiroshu

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ahickman

Glad to hear you solved your FP problem. Always nice to have spare parts from Dad's truck to help isolate the problem. Makes me wish I had two identical trucks to swap between.

Thermo sensor could be your problem and was suggested above. Don't see where you mention that you checked it per FSM. Take you ohm meter out there, unplug the harness from it and see if it is bad. Replace if not to specs.

The leaking fuel line could most definitely be a source for your problems. No fuel pressure, no fuel at the injector. I would think, however, that you would have smelled the fuel long ago if it was a significant leak (enough to lower fuel pressure at the fuel rail).

Kiroshu

UPDATE!!!!!!!!!!!!!! Ok everyone knows where the coolant temp sensor and cold start time switch are right next to each other bellow the thermostat and rad hose. I HAD THE WIRES CROSSED!!!!!!! THAT WAS MY STARTING PROB THE HOLE TIME!!!!! FUEL PUMP WAS WASTE AND SO WAS RELAY!!!!!! I took them off the clean a week ago and that was it i mixed the wires OMG!!! so it starts up like a champ BUT the hesitation prob was still there and i was thinking..... well i took off the fuel cap agian and it stopped..... crazy huh still don't know what it is.... ok so i thought for a mine it has to be either vacum/emissions or fuel related.... but everything fuel was perfect and brand new!!!!! Ok so i though ok i haven't replacd the pcv valve.....well i replaced that AND i took a hammer to the charcol cannister and beat on it a few times thinking it would do somethin..... OMG knock on wood (which i did) its STOPPED!!! all the hesitaion and stumlbing has stopped i drove it 20 miles and it stopped!!!!. I'm not sure if it was the pcv or me hammering the charcol cannister but it stopped. BUT!!!! It still does have random miss here and there. Its not serious... it only missed like 3or 4 times on my way how which is not bad..... tommarrow and staurday i plan to set the timing correctly and MAYBE adjs valves...... lemme know any imput guys i'm working on it....

Kiroshu

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Kiroshu

Update!!! Truck is still running superb not stumbling or nothing. It has little miss here and there but i replaced the dist cap and button to see if that helped. not sure yet. but i'm still running it with gas cap off it runs amazing tomarrow i'm going to set timing and see it it helps a little bit. thanks for all input guys i think i have solved my prob. THANKS YOTA TECH PEEPS!!!!

oldblue

the gas cap will have absolutly no affect on engine performance.

Kiroshu

i know its not supose to but when i had it on it hesitated and stumbled but when i stopped in a parking lot and took it off IT STOPPED!!! i dunno if the truck was messing with me or what but i swear it did.

DupermanDave

could be psychological. Like a placebo.

Kiroshu

ya know with all the stuff thats gone wrong and weird i would no doubt it but the truck is running amazing now and my trip to tennesse is tomarrow so yea wish me luck guys lol.