engine giving me issues... movies and photos included

[rags]

Were you seeing 4 lbs as the engine was acting up?

 

Joe

[crazyoctopus]

it was before i got the engine running. second test of the day right after compression.

[yetterben]

Flow is just as important. If youre going the su route check out paltech they are just as good as z therapy and loads cheaper. Throw some triples on there for some fun Hell i will even sell you a intake cheap

[crazyoctopus]

found a set of weber triples for $600 with intake manifold, just need to decide if that is the route that i have to go. last thing I want to do is just throw money at car without knowing exactly where the problem lies.

[crazyoctopus]

So the engine started, but it took a bit of time for it to actually run normally. When it did run properly it only lasted for about 45 seconds, and then the car died suddenly. It didn't sputter or choke out, it just died as if i turned it off with the key.

 

pictures of the plugs right after I took them out this morning, before putting them back in I cleaned them yet again with carb cleaner and a golf club brush.

 

plug 1

 

plug 2

 

plug 3

 

plug 4

 

plug 5

 

plug 6

 

I am going to pull the plugs shortly and see if there is any change in condition.

 

Here are the results of the comp test this morning.

 

1 - 150

2 - 149

3 - 150

4 - 150

5 - 146

6 - 150

 

avg - 149.2

 

Maybe I made a mistake when I did it yesterday, by dropping the timing to 12 deg, or because this time i removed all of the plugs before i did it; regardless, the comp on each cyl is still just about on avg.

 

Before I started the car I added a dollop of bearing grease, rags idea, around the throttle bearings hoping to stop the possible vacuum leak, but it really didn't seem to do anything at all.

 

while the car was actually running as it should I sprayed the crap out of everything front to back, and top and bottom listening for a change in rpm. Once I heard it in a particular spot I put on the straw and tried to localize the drop. Even with bearing grease on the throttle bushings (on both ends, and on both carbs) I was hearing a drop in RPM whenever I sprayed the side where the linkage comes into the carb body, not on the outboard side.

 

So does this mean that it is time to get new carbs? or should i try cleaning them again and see if the problem persists?

Edited March 11, 2010 by crazyoctopus

[rags]

Check the fuel pressure when the engine is acting up. You need 4 lbs (or there about) at all times.

[crazyoctopus]

i'll grab a T fitting next time i am out of the house and hook up my gauge.

[yetterben]

Those plugs are very rich looking......are your floats vented? When i got mine some a$$ hat had run a hose connecting the two vents and it ran like poop.

[crazyoctopus]

just pulled the plugs not 5 minutes ago and this is what they look like

 

 

and yeah my floats are vented properly, i am pretty sure i sprayed carb cleaner through them while i was dismantling/cleaning them. I'll check again once I pull them out and do another check of float level

[yetterben]

per the phone conversation..throttle shafts are probally fubar let alone what else on the carbies. 4.5 out just to make it run indicates huge leakage somewhere most likely the linkage.

[crazyoctopus]

yep yep yep.

 

an hour ago I took off the carbs and looked for anything that seemed out of place, and noticed that the backside of the butterflies, the back side of the piston, and the entrance of the intake manifold were damp with fuel. Note: the engine was sitting for 5 hours at this point. So I wiped it all down, pulled the floats and checked their levels still 24mm. checked all of the bolts and nuts to make sure that they were all tight, they were.

 

took a bit of coercing but she finally started to sputter, and while they were chugging away i pulled out the #4 spark plug, nothing happened. I pulled #2 and there was a drop, then it died.

 

 

It seems that with all of the tests that I have done, the issue is indeed with the carburetors; and more specifically the vacuum of the carbs.

 

solution send the carbs in to get a complete rebuild, get a new set of SU carbs, or buy some triple weber dcoe 40s.

[Daeron]

took a bit of coercing but she finally started to sputter, and while they were chugging away i pulled out the #4 spark plug, nothing happened. I pulled #2 and there was a drop, then it died.

Usually, if you pull off a spark plug wire and nothing changes, that indicates that cylinder is not firing. Since you are running carbs (and cyl 4 shares fuel with cyl 5 & 6) and cylinder 4 is effected singularly, it would tend to indicate an issue with spark to cylinder 4 (plug, wire, possible bad cap contact points?)

 

But if I am missing something, or just plain wrong, and you DO need to replace the carbs, the Z-therapy SU rebuild/swap program is the simplest and least expensive bet. Webers take finesse and (ideally) a large collection of jets that not everybody has. In a sense, you need to "commit" to Webers through jetting expertise and tuning equipment the same way you need to "commit" to standalone EFI through map programming expertise and (slightly different, but mostly the same) tuning equipment. You can get it close enough, easily enough, but its a pretty involved task to train yourself in knowing how to really dial them in just right.

[crazyoctopus]

the other reason that the #4 plug might not have done anything is because the rear carb have have been constantly flooding the engine, and removing the plug did absolutely nothing.

 

tried again this morning and noticed if i push up on the piston the RPMs when the car is running like crap, it doesn't change its pitch/tone/rpm whenever i lift the rear carb's piston. So it is as if the rear carb isnt doing anything at all. In the 20 min of intermittent running, it did not once get into a sweet spot where the car ran fine.

 

This evening I am going to head out and look at a set of triple webers that a local is selling, and if they are in good condition I am just going to go that route. Not too worried about the tuning part of the carbs; where I live the temp is about 73deg 80% of the year, and with my rotary background I am more than fine with turning a few screws every couple weeks.

 

And when you think about it, these carbs have been run since the 60s where the only bit of technology that you needed on you was a screw driver, gum, and a good ear. And as far as the jetting goes, my engine is a super stock, and there is more than enough wisdom/books on these forums to dig through to get all of my answers. So I am not too worried

[rags]

Nothing happens when you lift up the piston? Do you realize lifting up the piston introduces more fuel by pulling the needle jet out of the bore akin to choking the engine? If this did nothing and the plugs are the ones you show in the pictures, when you change the carbs please send me your old ones. You are running out of fuel. Either the floats are sticking, you have a blockage, or the pump is bad. You can't troubleshoot anything unless you verify you have fuel pressure when the car is acting up!

[crazyoctopus]

just installed the T and the gauge, constant 3.75 - 4psi.

 

within the last week i cleaned the floats and carbs. a couple days ago i pulled the carbs and floats again and cleaned them with carb cleaner and cue-tips. so i highly doubt there is blockage anywhere. I checked the float levels and cleaned the float inlet and vents again.

 

I am going to pick up a set of spark plugs on my way back from base in a couple hours and see if that does anything, but i really don't think it will.

 

i have mentioned "lean pop" a few times and just to make sure that I am using the correct terminology; it is when you see white gas spurt out of the carbs at high velocity, usually accompanied with the sound of a pop/backfire. when either of my carbs are anywhere below 2.5 turns from lean the carbs have done it to me, the only way that the engine seems to get to run is when they are at 4-7 turns from lean.