Rebuilt 2F seems to be going down hill (1 Viewer)

[Hip2bSquare]

I've started a couple of threads this week with random questions trying to diagnose issues, but I thought I'd try one last time before I call in the professionals (anybody know a good professional close to Little Rock AR)? My rebuilt engine is going down hill.......

I had my 2F (11/78) recently rebuilt. I replaced all accessories on the engine (fuel pump, water pump, thermostat, hoses, fuel lines, new pcv valve and grommet, new vacuum hoses). I installed a Performance HEI distributor with Live Wires with a relay to power the distributor. I had Mark - 65swb45 - rebuild my carb (along with my steering box).
I started the break-in process Friday. Prior to turning the key I primed the oil system (and confirmed oil pressure) and primed the new fuel lines and carb. I did have initial trouble getting it to start due to a timing issue. I got that resolved and ran the engine for 25 minutes between 1500 and 2200 rpms with vacuum gauge showing around 20. I thought it sounded great and it ran very smooth. I let it cool down, changed the oil filter, and topped off the oil (I'm using break-in oil from the rebuilder who also recommended the oil filter change). The engine won't idle without choke (I can hardly get idle below 1000) with vacuum showing about 16. Classic vacuum leak symptoms (according to my many hours of mud reading). My idle solenoid is working. Engine is desmogged, so not many potential vacuum leak locations. I tried propane and carb cleaner to find a leak and couldn't find anything. I built a smoke machine and tried to pressurize intake through the top of the carb and tons of smoke leaked out of my carb (should this happen?). I removed carb, bolted a wood plate with gaskets to cover carb manifold opening and redid smoke test, but didn't get any smoke from manifold gasket (I could only get smoke to come out around the wood plate). I polished my intake manifold during the rebuild, so I'm sure there are no cracks. The manifolds were NOT surfaced. I can't find a machine shop willing to do it, so I used a Remflex gasket. I happen to have a never used troll hole carb. I installed that carb as a test, but it also needed choke to idle. I did drive the 40 about 35 miles this weekend and it ran great expect for the high idle. However, after switching the carbs and trying to find the vacuum leak the engine is NOT running smooth any longer. I tried to drive it again last night and I have a lot of hesitation when I give it gas (and I did notice gas seeping out of the carb on the side facing the block after trying to drive it). I rechecked the timing last night and I think it was about 12 btdc at around 1000 rpms. I think a couple of days ago it was showing around 18 btdc at around 1550 rpms (I don't remember exactly). At higher rpms (1500 plus) the vacuum is very steady at 20. When idling around 1000 it's 15/16 with a little movement of the needle. When I give the accelerator a good bump vacuum drops to around 4/5 and then jumps up to maybe 22...which I've read sounds normal.

I know this sounds like classic vacuum leak but Is 15/16 on the vacuum gauge really not enough to pull fuel from the idle circuit? Would a vacuum leak at the manifold of 4 to 5 hg be hard to detect? If I pull the manifold off do you think a visual inspection of the gasket would show signs of a vacuum leak?

 

[Casey E]

Did you place card board over carb when running and make sure it dies ?

 

[Casey E]

If it continues to run you obviously have vacuum leak.

 

[Hip2bSquare]

By accident. I forget what I was doing, but I had my hand over the carb. I think I was trying to block some light glare to see down in the carb. Anyhow I guess I got a little too close and it sucked my hand down and killed the engine. I wasn't expecting that and it made a heart rate jump up pretty fast!

 

[Fj moneypit]

I’m no expert but your timing seems to be a bit high. Maybe adjust your advance. Have you rebuilt carb?

 

[Rigger]

Have you rebuilt carb?

He said Mark Algazy rebuilt the carb.

 

[Fj moneypit]

He said Mark Algazy rebuilt the carb.

Not sure why gas is seeping out the side. Maybe ask @65swb45

 

[Solace in Solitude]

Leaking where on the side?

If it’s seeping out around the carb isolator (under the carb), you need to snug down the nuts on the carb studs. That’s a vacuum leak.

You may have had it snug initially, but running it, the nuts may need to be tightened again.

You said HEI, I think you meant DUI. But, they are similar.

Does your DUI have a vacuum advance module? Are you pulling vacuum from the vacuum advance port? Is the other end of that line connected to the valve cover side of the carb, top center port IIRC?

Spray carb cleaner around the DUI vacuum advance module, just to be sure you don’t have s vacuum leak there.

Your timing should be about 12* BTDC at 650 rpm. Vacuum should be 15-20 and steady.

Plugs should be hot plugs, like Denso (3013) W14EXR-U and should be gapped at about .050”.

I presume you are sending full battery+ voltage to your DUI and not sending voltage from the resisted 10ga BY (it has a Yazaki 10ga Pink resister spliced into it).

If you can’t set idle below 1000, try the lean drop method to set idle mixture.

 

[70fj40]

“A professional close to Little Rock Arkansas”

Bobby @ Cruiser Company is in Little Rock Arkansas on Col Glenn rd. He is on Mud and posts in the Razorback Landcruiser Forum.

 

[Hip2bSquare]

Thanks for replies everyone BTW.
The side of the carb facing the valve cover (around the idle mix screw and vacuum advance hose) was wet with fuel.

At one point I pulled the carb and noticed the insulator under the carb base was a little wet with fuel. I sprayed the carb base with carb cleaner while running with no change in RPM. I know carb base gaskets are controversial, but I installed one just to make sure I had a good seal once I suspected vacuum leak.

Distributor is vac advance connected to carb next to idle mix screw, and distributor is powered from a relay.
The one item I haven't checked for a vacuum leak is the distributor, so I will do that.

It absolutely will not idle below 900, but it sounds like my timing may be a little slow (retarded...is it PC to call a distributor retarded). If that's the case I'll have to move the dist. cap and wire.....not sure my dist. can turn much more before vac advance hits battery tray.

Vacuum should be 15-20 and steady.

So my vacuum is a little low, but is 15/16 too low to pull fuel from the idle circuit? I seems like I've read posts where folks talk about vacuum in this range without idle issues.

 

[thebigredrocker]

Great summary.

I've seen it mentioned fuel leaking out the forward facing throttle shafts isn't a big deal. Curious where fuel could be leaking on the valve cover side. Have you aimed a light down the carb throat during idle to look for fuel spray? Fuel level in sight glass good? Wonder if some crud migrated into your freshly rebuilt carb idle circuit.

I found spraying carb cleaner around the intake worked good. The increase in idle can be very slight. The leak I found was on #6 and took a couple sprays to verify. If you haven't re-tightened your manifold bolts, that might be worth a try. The machine shop that trued my manifolds had a big belt sander. Worked good. I followed FJ40Jim & MarkW's advice to use a Felpro gasket with the large flame rings. Dry.

Have you put a multimeter on the relay to see if it's allowing full voltage thru?

Other option on your dissy is to lift it an move a tooth over.

 

[Hip2bSquare]

I forgot to answer a previous question: NGK platinum gapped between .050 and .055.
Fuel does drip/spray from the primary nozzle. Fuel bowl stays pretty consistent at 1/2 full. I did verify, prior to break in, full voltage through my relay. After I discovered my idle issue it occurred to me I did reuse the hard fuel line from the pump to the carb. So I’m a little paranoid that something has stopped up the idle circuit (which is why I ask if 15/16 on a vacuum gauge is really low enough to defeat the idle fuel flow).

I guess unless I’ve missed some nugget in my reading I need to eliminate 2 possibilities:

1) figure out how to clean out the idle circuit (or find someone to run my carb on their truck to test)
2) pull my manifolds and find someone I can ship it too for surfacing.
Oh....but first confirm there is no vac leak on the distributor

 

[Solace in Solitude]

Thanks for replies everyone BTW.
The side of the carb facing the valve cover (around the idle mix screw and vacuum advance hose) was wet with fuel.

At one point I pulled the carb and noticed the insulator under the carb base was a little wet with fuel. I sprayed the carb base with carb cleaner while running with no change in RPM. I know carb base gaskets are controversial, but I installed one just to make sure I had a good seal once I suspected vacuum leak.

Distributor is vac advance connected to carb next to idle mix screw, and distributor is powered from a relay.
The one item I haven't checked for a vacuum leak is the distributor, so I will do that.

It absolutely will not idle below 900, but it sounds like my timing may be a little slow (retarded...is it PC to call a distributor retarded). If that's the case I'll have to move the dist. cap and wire.....not sure my dist. can turn much more before vac advance hits battery tray.


So my vacuum is a little low, but is 15/16 too low to pull fuel from the idle circuit? I seems like I've read posts where folks talk about vacuum in this range without idle issues.

15-16 is enough, but you said you’re reading it at 1000+ rpms.

15-16 at 1000+ rpms is not the same as 15-16 at 650 rpms.

Back you idle mixture screw all the way out and check the condition of the tip... a PO may have screwed it down too tight and mangled the tip.

If the tip is good, gently snug it all the way down and then back it off about 3.5 full turns.

Try to get idle down to 650 with timing at 7*BTDC.

That will give you a starting point to get it to the numbers I posted earlier.

 

[thebigredrocker]

Ahh...Main nozzle dripping fuel at idle. I would pull the Solenoid and mix screw and see if blowing compressed air doesn't help.

Ding, ding, ding, we have a winner!

Pin is right on. fuel dripping from the nozzle can only be caused by two conditions:
1. Extremely high float bowl level, or
2. lack of idle fuel, necessitating turning up the idle speed screw until enough airflow is produced to begin fuel draw from the main nozzles.

Since your float level is good enough, that leaves condition #2.

And it is not a problem w/ air leaking around the throttle shaft. The little bit of shaft leakage that normally occurs in all carbs is easily made up w/ the idle mix screw.

While the solenoid is out, you might confirm it retracts 6-8mm when 12v is applied.

I had a solenoid that was acting up so I ran a dedicated ground to the solenoid. It clicks every time now.

What circuit is powering your solenoid? Likely unrelated to your problem, worth thinking about though

If I remember correctly the idle solenoid connected to the same wire as the coil switched ignition wire (BY wire on + side of coil) However some say that is not a good idea due to the fact that if you get a short in the idle solenoid wire it can take out the ignition circuit which is NOT fused on older trucks! A better solution that I build into all my new harnesses for older trucks, is to use the 4WD light as the idle solenoid power source. I simply use a double bullet connector when I build a new harness and make up an idle solenoid wire to plug into that.

I can supply you with a small splitter adapter and a length of wire. You would unplug one side of the 4WD light, plug in the splitter adapter, plug the 4WD into one side of the splitter then plug the idle solenoid wire into the other and route it out to the idle solenoid. Th 4WD light is on a fused circuit.

 

[Hip2bSquare]

Idle mix screw/pin looked good to me (I checked it a couple of days ago) even though I know that wouldn’t get past Mark.

I had confirmed the solenoid was clicking, but yesterday I put a meter on the wiring harness connection. It was reading very low voltage. I have the 1 wire solenoid. The last time I ran it I powered it direct from battery, but no change in the idle issue.

 

[Infinity00]

Also confirming what solace said, my 60 runs great at idle with 15-16 vacuum.

Any thoughts on valves going out of adjustment?

 

[Hip2bSquare]

Also confirming what solace said, my 60 runs great at idle with 15-16 vacuum.

Which implies my issue IS with my idle circuit.

Solace: forgot to respond that I have tried adjusting idle mix but it will not idle without choke or some throttle.

Any thoughts on valves going out of adjustment?

I did pull the valve cover to confirm oil (and I did confirm oil pressure during initial break in). My plan was to check valves after initial break in but my lack of idle has stopped me. Perhaps I should check them cold just to make sure there aren’t any glaring issues.

BTW: here is my attempt to find a vacuum leak on the manifold.....

 

[Infinity00]

You have the carb off, just rear into it. I had to do that a couple times to get the gunk out of it. Make sure the screen is there. I got junk from some old vacuum lines once, and something else another time. It happens more frequently than you’d think.

I was def having vacuum leaks and put the thick @cruiseroutfit gasket in between everything. It sealed it all up great and no more problems.

 

[pjohnson]

When you had it apart, did you inspect the area on the intake manifold where it bolts to the exhaust manifold for cracks?

 

[Hip2bSquare]

I did and no cracks. I also installed the block off plate and gaskets because the heat riser flap was toast.

Ok I pulled the air horn off the carb tonight. I’m about to do some research because I’m sure this has been covered, but......
What is the route for idle fuel up to the solenoid? And should I see something move on the solenoid when it clicks (because I’m not seeing any movement)? Ok there may be a very slight movement in the holes in the end of the solenoid, but very little.
No clogs from the solenoid down to the idle circuit opening. I thought I read somewhere the opening in the very bottom of the fuel bowl is where the idle fuel comes from but I have been unable to spray any cleaner through that opening?
All the circled holes in the top seem to be connected so I guess idle fuel comes up the same opening/jet for the primary?