fj running rich (1 Viewer)

[Kschep]

ok so my 40 has been running rich since i bought it. P.O. ripped out emissions system. im in CA and I just got a sticker dont ask how...lol...anyways the main story i need help with is getting it to run without me having to turn the fast ide up basically all the way AS WELL AS having the choke out halfway just to keep the damn thing running at stops when i rpm down.
super annoying. Guy says just get a new carb. So im like okayy i could do that and im happy to do that but because P.O. ripped out emissions system, if I ordered a new '76 carb I'm nervous that I'd have to adjust it to work with my rig - meaning if no emissions systemprese t then all the vacuum lines that go to the carb are non-existent. therefore i just cap them?
i have no idea how my P.O. (or his mechanic) manipulated the carb to work. after studying it (the carb) its a combo of two different years - top part / bottom part - 2 different years (if im correct - i looked on the carb identifier on SOR so im pretty sure im correct).

I also know tons of people rip out their emissions systems so there should be some easy way to deal with a new carb.

i bought a rebuild kit for a '76 carb - took the ****er apart, cleaned the jets added the new seals and whatnot - put it back together - same ****ing problem. so im exhausted by this, I just wanna be able to drive my 40 without tasting gasoline in the nostrils. lol
anyways im thinking smaller jets i dunno, im lost on this and no one around me will help me. ive tried valley hybrids, mudrak. they are the only ones close to me, but i cant get them to even look at it. super annoying. their always "busy" and i cant "get in line" bec their 'workload is too high" ... I just need an assessment and ill do the work myself s***.

do you guys think i should just a new carb or what?

thank you for any assistance or suggestions based on what i said.

 

[70fj40]

Running carb, proper vacuum and timing correct should give you a good start to not running rich. You can’t get there without the proper vacuum so I would start there since your carb is at least running. Instead of plugging the vac lines connect them. FSM will show where they should be located.

 

[90WT]

Yep, start with checking for vacuum leaks. That could be hoses. It could also be intake/exhaust gasket. Gotta rule out vacuum leaks and timing before carb changes.
The carb running rich could be a couple of different things. It helps to narrow down when it's rich, or if it's rich in all of situations.
Assuming your carb isn't all gunked up and the linkages are all in working order.
There are four circuits of your carb (think of it like four different tasks).
1) Idle (fixed by idle screw and idle speed)
2) part throttle on single barrel (you can swap out the primary jet to modify)
3) Wide open throttle (you can swap out the spring of the power valve)
4) part throttle on second barrel (you can swap out the secondary jet to modify)
In order to make it way easier to determine when my carb was running rich/lean, I installed a wide band O2 sensor. Together with a vacuum gage, you can dial in the carb without a bunch of guessing. It takes some time, but it's Zen time learning how to whisper to your carburetor.
Swapping jets doesn't necessarily fix your problem since the jets are specific to a particular circuit.
Youtube and a couple of Motortrend videos helped me understand the carb circuits and the value of a wide band O2 sensor.

Post up your progress, guys here will help you along your way.

 

[bhsdriller]

Lets see some pics as well

 

[charliemeyer007]

Are you sure its only carb issues? I'd be checking the vacuum readings - a small leak makes a big difference at idle, not so much at WOT. What is the wet and dry compression? How old are the plug wires and the cap and plugs themselves? How much play in the distributor shaft?

My 72 came with a 2 bbl Rochester and a Delco distributor back in 82, I have been very happy with that set up.

 

[Kschep]

No I’m not totally sure … but I’m pretty damn sure it has something to do with the carb .. but it could be a combo of carb and another issue simultaneously

I’ll get pics of it for you guys no prob.
It’ll show you what’s missing and how my PO or his mechanic Jerry rigged it after ripping out emissions system.

 

[Pitter Patter]

You may be able to find people willing to sell you their emissions components.

 

[Kschep]

You may be able to find people willing to sell you their emissions components.

I have already collected every emission component I need - in case I couldn’t get it smogged - I am in CA, and not just CA .. the Bay Area of CA … meaning near SF where emissions testers are basically nazi’s … so I found a contact that works at the dmv and I got a sticker …. Just got it!!! So I don’t need to put it on - in 2 years I might have an issue - but I’ll just make contact again and pay the $500 fee for the funny smog. Whatever. I just don’t wannna drive around tasting gasoline - and having to choke out halfway just to keep the car running at stops, lol.

pics coming next….

 

[mattressking]

By choking the engine that means you have to reduce the amount of air going in to balance the air fuel ratio, therefore you have an under-fueling issue or large vacuum leak.

Hook a vacuum gauge up and see what it says, make sure needle is solid and not fluctuating/swinging. If by swapping/rebuilding carbs didn't resolve, my guess is that you have a number of or a large leak that needs to be resolved. You want to see at minimum 18inHg at sea level to rule out vacuum...for now.

Also ensure all 6 cylinders are firing and spark plugs are gapped/clean.

Lastly verify if the fuel level is in center of carburetor sight glass.

Test and return with results. There is no other way to help keyboard resolve without this basic information.

 

[Kschep]

Ok choke comment makes sense…but I don’t know how to do the vacuum test you mentioned, so I’ll need to be coaching on that as well,
but here are some pics for everyone …

 

[mattressking]

Google testing vacuum, or search mud. It’s covered an immeasurable amount of times

 

[charliemeyer007]

It looks like you have a header. See the thickness of the steel header flange vs aluminum intake - can't tell if they have a half washer to shim out the thickness so the stud can apply equal pressure to both sides.

I custom made step washers to do do just that along with longer studs and 2 header gaskets that were fitted wet. I also flat planed both surfaces first. No leaks ever. I posted some pic's along time ago

When you first start your engine cold, lightly spray something like WD-40 along the intake/block seal - listen for rpm change, a leak will speed the engine up when the spray hits the spot. A fire extinguisher is a good plan and do it outside.

Brake booster can leak, listen under the dash. Put a big hemostat on the vac hose. #5 cylinder will develop issues first - plug condition and compression

 

[Kschep]

Google testing vacuum, or search mud. It’s covered an immeasurable amount of times

yeah my bad i shouldnt have made that coaching comment bec duh look it up on yutueb or mud its been done...so my apologies as someone who konw how to search mud fo threads etc...

 

[Kschep]

UPDATE:
ripped off the air intake to get at my manifold ( i do not have an exhaust manifold on the car because of the tri-Y headers.
although i did buy it brand new off Spector off-road (again, because i thought i was going to have to do a complete re-do ofthe engine compartment just to pass smog and get a friggen sticker so i can actually drive the MF on the street.friggen $650, but its prestine and bagged up just in case in 2 years my contact cant help me anymore.

anyways for the update!! : grabbed me some carb spray, took off the air intake and then fired the engine; - vrooooom right away, engine starts up with 0 issues, well if i pump the gas peddle 3 times before turning the key no issues, of course - lol

so i see this little it'ie bittie crack looking think in my manifold, so i said lets spray that - engine rpm'd up - so theres one vac leak (so i need a new manifold) - i started looking loser at the manifold/tri-Y conection to engine at gasket and sprayed some toward the bak next to where the carb is and Again, rpm'd up....

CLEARLY I HAVE VACUUM ISSUES AT THE MANIFOLD AND RUNNING ALONG THE GASKET....took some pics so will post those next to show the little crack, and then where i sprayed in the back where it clearly RPM'd up

Also, my carb idle mixture screw does nothing - i turned alll the way out then all the way in NO change whatsoever, so theres something 1000% happening with the carb too - made contact with Jim C. and while i fix the vac leaks / maybe just buy a new manifold / he said he'd rebuild my carb to perfection and that i hae a really rare nice non-usa carb thats perfect for my altitude whatnot blah blah, so Ill be dealing with both of those issues and im sure once i get that carb back with addition to the vac leak fixes, my rig should be on point. ouuuuuuuuuuuu i cant wait...

Recommendations for further actions or suggestions or maybe something im not thinking about, please... ty

 

[Mark W]

Is your idle circuit cutoff solenoid connected? Is it energized? Is it funcioning?

Aside for everything else said in this thread, I see no mention of the solenoid at all. Maybe I just overlooked it as I scanned. From the symptoms you mention, that is the very first thing to check.

Mark...

 

[Kschep]

Put a marker at the spots - but just looking at the engine -to- gasket to tri-y / manifold bolt connections it just looks shotty … can someone tell me with the tri-y headers that that connection looks clean? Meaning it almost looks like they cut certain portions to make it fit with the manifold…or is that just normal? Irregardless I’m gunna change the gasket it’s super old obvi - replace the manifold. Put it back together and see if I have any vac leaks again.
Are there any other important parts to check for vac leaks other than that main connection point ??

 

[Kschep]

Is your idle circuit cutoff solenoid connected? Is it energized? Is it funcioning?

Aside for everything else said in this thread, I see no mention of the solenoid at all. Maybe I just overlooked it as I scanned. From the symptoms you mention, that is the very first thing to check.

Mark...

Yes - bought a brand new one from ToyotaMatt and it clicks fa sho. My carb guy said same thing to check

 

[Kschep]

Ok so anyone with experience marrying the manifold with the tri-y headers? Why doesn’t it look cleaner, like that bolt tightening everything you can see all the threads through the gap. Weirdly I didn’t get any rpm change there mainly front at minor crack and toward back between gasket and manifold-end.
But definitely addressable issues & with my gas mixture screw literally doing nothing on my carb supports a lack of gas build up in Carb bowl which is why I have to pump my gas pedal three times to get some of that gasoline spray going into the carb.
And then of course I have to have my choke out bec of the vac leaks.

 

[bhsdriller]

just looks like a bad fit between intake/header, maybe have them machined flat as an assembly. Can try a remflex gasket they are usually pretty good with sealing inconsistencies.

 

[Kschep]

I have all this new stuff I purchased a kittlenwhilenbacknassuming I’d never get smogged. So I have a new intake as well as exhaust that were “re-machined” and got then new gasket too….im wondering bec this car was competed back in 2002 as a rock crawler. And then owner PO got health issues and sat in the back of his yard in the sun for seven years before he died, and then his son sold it to me. In that timeframe maybe the gasket itself just got two sun fried. And I’ll try the new one I have and see what happens.