rce311

I'm fresh out of ideas. I had my valves done and heads resurfaced on my 90 poor-runner. when i first started it up, it ran great. i let it sit idling for about 10 minutes to make sure there were no leaks, and once it warmed up, i decided to take it for a quick spin. that's when it happened. as soon as i stepped on the brake pedal, it started sputtering and idling really rough, worse than before the valve job. when it was idleing before, nothing coming out the tail pipe. after i hit the brake pedal, nasty, gas-rich smoke came out the tail pipe.

I've checked vacuum lines, timing belt, and fuel lines. timing belt was good, didn't jump a tooth or anything like that, but i cant set initial timing until its actually running proper. any thoughts, ideas or suggestions please?

abecedarian

kind of a 'catch-22': can't set the timing til it idles properly, but can't get it idling properly if the timing's not set.
Me... I'd adjust the idle down to below 900 (after the engine's warmed up), then insert the jumper (TE1-E1 in the diagnostic connector) and further fine tune idle and timing.
Oh, and the TPS needs adjusted properly too... otherwise the above suggestion means nothing. <-- hint hint.

rce311

well, when i start it up now, it runs like crap. timing goes from +-10 degrees to +-10 in the other direction. plus the engine is idling very rough at about 500rpms anyhow. and then as i hit the brake pedal, it stalls out completely now. does this thing have a map sensor? is it possible to have a fuel line crossed up with a vacuum line and not even know it?

turborich

Sounds like your brake booster has a vacuum leak. Pull the vacuum line off & plug it, see how it runs then.

rce311

tried that and i still couldnt get it to idle right. once you hit the brake, it idles like junk. weather or not you take your foot off the brake or not. even if you turn off the engine and restart. its still not correct.

TNRabbit

It sounds kinda like the timing belt was put back on incorrectly.

rce311

ok. i spent another 3 hours today trying different things. it seems that for some reason, when you step on the brake, or hit the gas, it either stalls out or goes to rough idle, and smells like its running rich. timing belt is installed correctly, timing is correct, verified by taking off timing cover and setting engine to TDC, all the vacuum hoses are installed properly and no vacuum leaks. i dont know if this means anything, but when i unplug the TPS, it seems to idle better, until you hit the brake.

i've got $100 and a case of beer for whoever can figure this out for me. im getting frustrated, and starting to regret buying this 4runner. i just wish this thing would run like my '04 TRD tacoma.

http://www.facebook.com/home.php?#/p...&id=1630203330

OutlawMike

Have you checked to see if the ECU has thrown any codes? That is a place to start, it might tell you what is wrong.

It was mentioned above that the TPS needs to be in adjustment. Have you verified the resistance measurements at the TPS, as per the FSM?

When you say that the timing belt is correct, you are verifying that the timing marks on the cam sprockets line up with the indentations on the sheetmetal behind them, when the motor is at TDC?

Are you absolutely certain the motor is at TDC on the compression stroke? It could be 180 out and at TDC for the exhaust stroke. Not trying to insult you or anything, I do not know your relative experience with IC engines. This is a common one to get wrong. I did it when I was 19 on a SBC 350.

Did you check the valve clearances before putting the heads back on? Maybe the shop screwed the valve clearances and you have valves open at all times.

A compression check would verify that all of the valves are seating properly.

I will be curious to see what you find out.

Good luck,

Mike

Mic09dcsm

I could only wish we got the 3VZ-FE, much better engine, the 2nd gen Camry got it though, we got stuck with the 3VZ-E.

snap-on

brake induced idle problems are 99.9% of the time, vacuum problems.

"not a vacuum leak" is based on? you have a vacuum guage hooked up and can watch it pull good vacuum, and watch it when a friend steps on the brake?

start with vacuum problems, second is trimming issues, start with the distributor and work toward a off-by-a-tooth timing belt issue.

rce311

ok. here's the scope. did a compression test and here's the outcome:
cylinder 1: 180psi
2: 180psi
3:190psi (was originally dead cylinder before valve job)
4:180psi
5:180psi
6:180psi
i think the compression is good. as far as timing; the timing marks on the engine all line up with the marks on the crank pulley and the cam sprockets at TDC. the distributor rotor is also pointing at the #1 spark wire. so the timing is correct. i have checked to see if the timing belt had jumped a tooth but it hadn't.
i vacuum checked the intake manifold and it held plenty of vacuum. the brake booster itself, does not. but is it supposed to? when you press the brake, air is pushed out the vacuum hose on the brake booster. hmmmm...
so i unhooked the brake booster vacuum line and plugged it with a vacuum tester and started the motor. about 12.5 hg of vacuum in the manifold. idled rough, but smoothed out after a few minutes. hit the brakes, slight change, rpms dropped a bit, but idled better. revved the motor once, and the motor choked and sputtered and rpms were at about 400-500rpms.

any other questions you have just ask. i want to help you guys help me. lol. maybe i should trade this thing in on a yugo. lol

abecedarian

what's the idle speed again?
The ECU will cut the injectors when the idle is above around 1200 rpms and you're in 2wd, when you depress the brake pedal, causing a surging in idle speed.
Also, if the TPS is not sending the "IDL" signal to the ECU (meaning the TPS is not adjusted properly or is malfunctioning), similar things can happen since depressing the brake pedal creates a 'vacuum' leak and since the ECU is still looking at the O2 sensor when the TPS is not signalling IDL, can cause an erroneous reading at the O2 (due to the 'air' that enters the system) and a fluctuation in idle.

rce311

idle speed right now is about 500 rpms.

abecedarian

should be about 800

rce311

yeah i know. if i get timing set at 10 degrees, and 800 rpms, it stays there till i either hit gas or brake. then it rough idles, and stays in the 400-500 rpm range.

rce311

OK folks! here's the solution. when i put all the vacuum hoses back into the intake manifold, i had crossed up to rather important hoses. a fuel return line was swapped with a power steering vacuum line. is cause all excess unconsumed fuel that would otherwise be on its way back to the fuel tank to be redirected into the intake manifold. basically flooding out cylinders 5 and 6. 20 minutes of idling consumed about 5 gallons of gas so we knew something was wrong. swapped the hoses back and it runs fine! now if i can just get my OD OFF light to stop flashing, we'll be in good shape. but ill put that in a new thread.
thanks for all your help and concern. without this site, i would be totally lost. thanks again.

ryan

85_yota

Can you post a pic, I am having the same problem. The intake is filling with fuel and obviously running like crap.. Thanks in advance

sjlrunner

I am having the same problem. can someone post a picture of the location for the fuel return lines and the power steering vacuum lines on the 3vze please