running rich (1 Viewer)

[swank60]

I am running out of ideas on this, and I'm desperate.

there doesn't seem to be any sort of mixture adjustment on the carb that I can find - well, except for the idle adjustment that's capped by the factory.

- It's got a fairly new carb on it (maybe three years old). I've gone through it all and cleaned it up. Floats are set fine, etc. I'm not sure about the
- the valves are set right
- new plugs, rotor arm, dist. cap
- smog pump was replaced about a year ago
- K&N air filter, just cleaned

it even runs rich with the breather hood off of it and sucking air.

it spits black carbon/water crap out of the tailpipe when I start it up in the morning, but other than a slight bobble (that's barely noticable) at idle, it runs perfectly.

Any ideas? I can't pass the HCs on my smog test (Fort Worth, Texas) - high speed or low. All of the other tests passed (NO2 and something else - i don't have the sheet in front of me.)

 

[IDave]

You can change to leaner jets, I am sure. That being said, I have done that with my 71 carb, and I still spit carbon water in the morning during warmup. Do you need to fix it to drive legally, or is it just a nuscience? (excuse my dyslexia).

 

[dd113]

You have mutiple adjustments on that carb. Idle, fast idle etc.... There is a mixture screw that is usually factory capped. The cap is put in place so normal people cant make their trucks run better with the emissions crap.

The capped plug is on the inboard side next to the valve cover. If you look down from the air rail you will see it nestled between a few vac lines. It is possible to remove it but it is a PITA. Refer to the OEM manual. Basic plan to remove it is to use a small bit to drill through the ctr of it large enough to get a small screwdriver through and tighten the screw. Then use a larger bit to drill through the cap. Eventually it will pull out then you can adj the mixture as needed.

I dont know off hand but check out the emissions manual on other possible causes prior to removing the plug

 

[swank60]

It does have to be legal. It's my daily driver.

And I'm worried about making that adjustment on the factory capped thing. I think there's something else up. Plus, as I understand it, that needle only affects the idle mixture. I'm running rich the whole time. Under load, at idle, at road speed, etc.

One thing that I realized overnight is this: for whatever reason, the truck started idling higher for no reason at all. It would warm up, and it would start idle at 1100 RPM (according to the tach on the dash.) - I backed off on the idle screw - in fact, it may be backed off entirley (though I can't remember.) and it still sounds like it's idling high.

 

[Pin_Head]

High HC indicates a misfire, while high CO would be a rich condition. Since it is both at high and low speeds, it is more likely an ignition problem or poor compression. Check the easy things first. What are the actual HC and CO numbers?

 

[swank60]

pin_head - here are my numbers
1540 RPM - high speed test (25 MPH)
HC(PPM): standard 310 - Mine: 479
CO(%) 2.49 standard - Mine: 4.44
CO2 - Mine: 11.9
O2 - mine: 0.2
NOx Standard 2198 - Mine: 449
dilution(%) >6 Mine: 16.3

Low Speed (15mph) 1549 RPM
HC(PPM): standard 315 - Mine: 512
CO(%) 1.80 standard - Mine: 4.34
CO2 - Mine: 11.9
O2 - mine: 0.2
NOx Standard 2359 - Mine: 475
dilution(%) >6 Mine: 16.2

I did a compression test not long ago, and everything seemed pretty good. I don't remeber the numbers, but as I recall, I was only about 5psi below factory - and all cyl came up the same (maybe 1psi dif.). The PO redid the head a few years ago, and the shop that did it told him to start running 20W50 in it...I run 10W30 in it now. I get a little smoke some mornings before warm up, and it does burn some oil, but not enough that I'd worry. Maybe 1 qt every 300-350 miles. (but it's hard to tell, it leaks like a stuck pig)

I'm putting a new set of wires on this afternoon - it's got new plugs, cap, rotor. The coil looks old, but that doesn't really mean anything.

 

[Pin_Head]

It is also running rich because the CO is high. Replace the air cleaner element, because its easy. Usually they run rich because 1 or more of the tiny air vent holes in the top of the carb are plugged. If the fuel siphons out of the bowl when you shut it off, this is evidence they are plugged. If the slow jet (atomizer) air vent is plugged it will run rich w/o siphoning. You can try hosing out the top and inside of the carb with spray cleaner, let it sit for a couple of minutes, start it, spray it again running, rev it up to 2500 and hand choke it (yes, you put your gloved hand over the carb) until it stalls. This pulls a vacuum at the top of the carb and pulls fuel out of the vents opening them up. Repeat if necessary. If this doesn't work, it is time to rebuild the carb (again).

 

[60wag]

It might be the carb, or it might be a malfunctioning emissions component. I used to have an 82FJ60 that failed emit test for hight CO and HC. I was digging around checking vac hoses and happened to pull one loose and liquid gas dripped out of it. Tuens out that the VCV in the evap system had failed and somehow made the engine run really rich. The evap VCV is mounted close to the carb cooling fan. Beign a natural cheapskate, I swapped the VCV from the distributor vent system into the evap system. That did it and I passed the emit test. Since then I've been through some emissions headaches with my 84FJ60. The air injection system is really important. The air pump, which often fails is only part of it. Make sure the air bypass valves are working correctly. I've also found that the "vacuum switch" can be flaky. It supplies an electrical signal to the emit computer based on vac conditions. Do you have the Toyota emissions book? Anyone who has to pass smog tests on an FJ60 ought to have one. Also make sure that the vac hoses connected to the carb are on there correctly - especially the ones near the valve cover.

 

[swank60]

I did replace the breather, so that's new, and new wires, etc. Someone had suggested to me yesterday to try the hi-rev-hand-over-the-carb bit, and I tried that. I'll try it again after spraying it down with B12.

On the emit stuff - that's what I'm afraid it is. Some weird vac thing that you could never guess in a million years. I tore everything down that on driver's side fender well yesterday - there was some carbon and crap in a few of the hoses, others had some gunk in it - nothing that seemed out of the ordinary considering what it does. I'll check out the VCV and other vac stuff today.

I don't have the Toyota manual - I'll order it though. I'm having to rely on the ever comprehensive Haynes manual...it'll have to do for now.

 

[Landpimp]

get the 80+ emissions manaual, a vacuume guage and a piece of hose(grab a meter of OEM stuff, 3mm).........with those 3 things you can test all the emission junk, its actaully pretty darn easy to do if you follow the manual. I found on my 82 fj40 that both the BSVS(the things on the t-stat housing) were both not working(open all the time) these wernt a real problem(and didn't make it run rich) and only effect the running when cold, but now fixed it runs so much better in the morning.

John H

[quote author=swank60 link=board=1;threadid=11752;start=msg107796#msg107796 date=1077290014]
I did replace the breather, so that's new, and new wires, etc. Someone had suggested to me yesterday to try the hi-rev-hand-over-the-carb bit, and I tried that. I'll try it again after spraying it down with B12.

On the emit stuff - that's what I'm afraid it is. Some weird vac thing that you could never guess in a million years. I tore everything down that on driver's side fender well yesterday - there was some carbon and crap in a few of the hoses, others had some gunk in it - nothing that seemed out of the ordinary considering what it does. I'll check out the VCV and other vac stuff today.

I don't have the Toyota manual - I'll order it though. I'm having to rely on the ever comprehensive Haynes manual...it'll have to do for now.
[/quote]

 

[dogboy]

i'm going to take a flyer on this one, but my suspicion is leaning towards an emissions component as well. i know that our '87 FJ60 is running rich largely due to a non-functioning EGR vacuum modulator (thanks 60wag) and my gerry rigged solution to smooth out the motor (which worked well, but created a run rich condition).
somebody correct me on this, but doesn't a run-rich condition degrade the catalytic converter over time? if so, maybe this is contributing to the failed emissions test.....

-dogboy- '87 FJ60

 

[swank60]

The rich running situation will screw up your cat after a while, but if your NOx numbers are low (from what I understand) that shows that the cat is fine.

here is what is really weird - I went through the carb (but only the top part, above the throttle body) about 7 times since thursday...one thing that worked pretty well, and leaned out the carb a little, was switching the venturis. It increased my acceleration like crazy...only, it started idling rough...could barely keep it running. So I switched them back, and while I had the top part of the carb off, I went ahead and did a chem-dip (one of those Berryman's buckets) of the metal parts that i could get to...the body, the slow jets, the venturis...and I put it all back together (with the venturis corrected and back in the right places) - so it ran even worse.

I pulled out the idle mixture screw (PO had messed with it - I thought it was capped) cleaned it and put it back in the way the manual stated (backed out 2 turns) - and also found a few vac lines unhooked from the back side of the carb...replaced all of that, sound as a pound, and it ran even worse.

Next, I backed out the idle mixture screw 1.5 more turns, and it smoothed out a little, but it still stalls. The idle seems to vary about 100-200rpm on the tach (underhood hookup, not the one on the dash.)

I think I'm going to post another thread about testing the EGR, too. The haynes manual had some tests, and it seemed to pass...there's the rub...and I went through EVRYTHING that's bolted to the fender well that has to do with the air injection...replaced hoses, etc...

It's never something simple.

 

[crawlin60]

My 86 60 is in the same boat. It sends out a plume of steam when I start it, and part of it may be the ethanol crap that we're forced to burn in Utah County. My symptoms were as follows: Idle was glassy smooth, not a lot of power. Had gotten wrong secondary diaphragm (without the elbow at the end) when rebuilding it and the right one had arrived and I put it in. Then out of the blue truck stalls and won't stay running worth crap. First thought was the idle cutoff solenoid, so I grab my spare carb and try that solenoid and no change. I next take the idle mixture screw off, clean it and blow compressed air in that hole as well as the cutoff solenoid. Checked that the metal gasket and oring were there. Idle is uneven, bucks and stalls at any time I'm not flooring it. Drove it like that for two tankfuls at the usual place. Then took carb off (which I rebuilt last fall) because among other checks I was making I notice my secondaries are frozen. No way the diaphragm will open it. I flip it and major rust buildup has secondary shaft frozen in bore. So it gets drenched in penetrating oil, then slowly gets freer and I forget to file off the flare in the screw end of the butterfly, break the heads off-damn. Grab the spare carb again and rob the screws off, use my 30-06 brass bore brush to clean the throttle shaft bore, also some steel wool on the secondary shaft, light coat of antiseize and reassemble, moves with a feather touch. Blow more air in all cavities that previously hit. Reinstalled, hooked vac lines again (not many, like maybe 6 or 7 and they lay where they should go) and restarted truck, still ran like crap with bad idle with mixture screw backed out 3 turns. Went to parts store, got a 20oz gumout solvent bottle and refilled at usual place with same cheap gas as always and added the cleaner into the tank. Drove about 100 mile round trip and idle is back to glassy smooth at 600rpm, ok power (haven't checked for linkage opening fully, or replaced plugged up air filter yet). Starts with 2 pumps, about 2 sec worth of cranking (onemississippitwomississippiwroom), but the steam cloud remains. Maybe my head is cracked, as I have a mistery coolant leak not at the radiator, but elsewhere. Moral of the story, if truck ran good, then went to the crapper don't start replacing stuff blind. Better for your pocketbook to retrace your steps and it helps if you have another 60 in the driveway to steal stuff from.
Try changing the gas in the tank, or adding a cleaner to take the buildup off inside the carb. Air filter, plugs cap and rotor are nice to replace if needed but maybe you shouldn't head that direction when troubleshooting.
HTH,

 

[IDave]

I have heard ethanol gas is very hard on these engines/carbs. I wonder if that is where your rust came from.

 

[swank60]

BigDaddy - it sounds like you feel my pain. have you fixed it yet?

I haven't changed gas stations (and I just filled up! yippie)... but I have done the chemical rebuilds...B12, some other Berryman's cleaner, Mystery Oil (in the tank, in the carb, in the oil) Heet (there's a procedure that i've seen mentioned here, where you fill up the carb with heet, let it sit for a while, jump in the truck and floor it in 4th...) - and did the suction thing 9hand over the carb...this was after running it without the cooling fan for a while. PO's mechanic (a local LC "specailist") left the censor off... and did the top end rebuild - the heat killed the accelerator pump, etc. That's why I didn't do a full rebuild - just the top end...and that's also why I think it's the carb, not the EGR - because I had my hands in it... also, every time I've pulled the carb apart, it's changed it's running characteristics...that also makes me thing it's the carb.

The PO said it was a brand new carb - maybe a year old when I bought it - but that plug for the idle mixture tells me it wasn't - maybe it was a rebuild (that was poorly done) or didn't hold up under the heat from the ex-man without the fan.

 

[crawlin60]

One thing I forgot to mention was that I found the carb bottom screws loose, so that the carb cleaner I had sprayed before bubbled when I had the air nozzle on the idle mixture screw. The bubbles were coming from the gasket between the middle and bottom section. So I think a vacuum leak was most likely present as well. I would check your manifold bolts to see if they're loose, like they were also in mine. You do it blind, with a 17mm in a 8in. extension 1/2in drive, going by mental picture only. I also keep finding my air rail nozzles loose and that also creates a vacuum leak. I don't know if vacuum leaks are your problem though, being that a vac leak will create a lean condition, not over rich as yours is. Did your truck ever pass emissions with this new carb? if not it could be that you're jetted too rich for the altitude you live in. My truck has a primary #147 and secondary #200, and I'm at 4770 ft ASL. Think back, when was the last time since the truck passed emissions and what changes you've made since. If you are running rich all the time, your enrichment circuit could be leaking (maybe the accelerator pump) or the float could be set so high that raw fuel dribbles from the vent tubes into the airstream, and enriches the mixture beyond the ratio created by the prim and sec jets. BTW, your secondaries should be closed for the emission test (ie. the butterfly should be closed) at idle and at 2500 rpm.
Also heard that coleman white gas in the tank (with little gasoline in it) burns super clean, and makes for some snappy clean burning tests