1725 - Where to Start ? To get it to Start

[mferris]

Need some help trying to get a '66 SV 1725 with Strombergs to start. This is my 2nd SV and my first experience with Strombergs (previous had been converted to 32/36 and now V6).

What I seem to have:
- 150+ psi on all 4 cylinders
- New Pertronix ignitionwith vacuum advance
- I've confirmed spark on all 4 plugs, and ensured gapped per WSM
- Static timing seems to be set correctly (turned it to 8 BTDC and set #1 plug)
- Firing order 1342, counterclockwise
- Mechanical Fuel pump, I've primed it by hand, and not other times
- Fuel confirmed at the fuel line into the carbs
- Valve cover removed (still off) and all valves moving - although I haven't confirmed if there is an order issue/cam install issue - but checking with my thumb - compression occurs on #1, then #3 - which is what I expected.
- I checked (cold) valve clearances - and they seem close to 0.012 and 0.014
- new battery (700 cca)
- new starter solenoid

I have not touched the Strombergs - but the car sort of ran on at least 2 cylinders a week ago - now I can't seem to get it back to even that, much less start to diagnose the other issues.

What happens:

1. Cranks fine (although at times the starter will not shut off, forcing me to disconnect battery - might be ignition switch issue?)

2. A sporadic single cylinder fires (don't know which one) - will repeat randomly - but I can get a cylinder to fire most times i try to start it

3. I have seen puffs of white smoke coming out of both carbs at times - never a loud backfire. Also - the valve cover is off - and I do see some very light smoke at times coming off the top of the engine - don't know if that is coming out of the valves or if coming up from the oilpan(?) - doesn't seem too bad.

Feels like something with the valves/firing order to me - but not sure. I've having a hell of a time hand cranking it since I'm having to use a pipe-wrench on the hand-crank - I might just get in there with a dremel to cut it off at some point.

Thanks in advance?
-Mike

 

[Greggers]

Did you set the Stroms by the WSM procedure (spin each carb's mixture screw up to where it just touches the piston then back it out something like 2.5 turns)?

Do you have an inductive timing light? Is it flashing at all as you're cranking? With Pertronix, I was having an issue where it wouldn't flash (weak spark?) until after I turned the key from start to on to off, Cyl 1 flashed and I got a single pop just before the key got all the way to off. I was getting good at doing start-on-off-on with the key. If I caught it just right, that key off pop led to more.

Giving it choke? Confirm that the choke cable is connected and functioning (I've seen it broken and/or not).

All that said, I'd bet on a timing issue. It's not unheard of for the timing mark to be off by many degrees. Confirm your 8 BTDC is relatively close to the real TDC on the compression stroke?


It's only about $15 for a universal ignition switch at NAPA for testing (and peace of mind (and eventual backup).

 

[tom o]

I just went through the same thing. I had the same symptoms. My problem was the wires out of the dist. #1 was 180 deg. out. moved the wires around and it ran great. When you have #1 on compression, pull the dist. cap and check firing order. My #1 is pointing to about 7:00. tom o

 

[mferris]

Tom/Greg - being just a hack at this I hope I did this right.

Compression: I pulled the plugs and valve cover, rotated the engine until I felt compression on #1, and saw that both valves for #1 were clear (i.e. not compressed), and rotated the crank until i was at 1.5 notches (aluminum head) BTDC. For some reason - the metal marker on my engine does *not* look like the ones on page 49 of section B of the WSM. Mine has a single pointer and is located almost vertically on the gear cover between the fan pully and crank - I'm not quite sure how to read it since it's impossible to see if I was to try to read it from straight above the fan pully.

Carbs: I removed the carbs and disassembled. Interestingly - the bushing retaining screw (that the Jet Adjustment screw sits inside of) was *not* screwed all the way into the carb. This was especially true on the front carb. I can only presume that the mixture was way off. I will screw the retaining screw all the way in, then adjust the Jet screw accordingly.

I'll also look at the timing light to see if I'm getting spark while cranking/strong/etc.


This thing is so clean and well maintained - I'm shocked I can't get it to run.

 

[Jay Laifman]

Are you doubly sure you are at BTDC and not ATDC?

 

[chazza]

If you are quite sure - as the others have suggested - that the static timing is set at BTDC on the compression stroke, then the easiest way to check that if you have it correctly set is to:
1. Remove the air cleaner and housing.
2. With the aid of an assistant open the throttle fully.
3. Use a mirror and a torch to look down the carburettor throat. I am not familiar with the Strombergs you have but if they are variable-jet you may have to lift the jet with a long thin screwdriver.
4. Squirt a liberal dose of starting fluid into both carburettors.
5. Retreat to a safe distance and crank the engine; if the timing and spark are correct the engine will fire instantly, run for a few seconds and then stall. If so this confirms that your problems lies in the fuel system.

If it doesn't fire, check your timing and distributor rotation and orders of the HT leads, etc. again.

If you prove that it is the carburettors, then it is time to strip them; clean them in carburettor cleaner; blow out all of the passages with compressed air and reassemble with new parts, including diaphragms if they are the variable-jet type,

Cheers Charlie

 

[johnd]

Tom O - I too just went through this - if the oil pump is clocked with the cam properly at TDC on the "firing stroke", I believe the rotor should be pointing to the 2:00 position (#1 cylinder). Prior owner apparently installed the oil pump 180 degrees out and decided to compensate by reversing the drive dog on the diizzy. Wish I had known!!!

 

[mferris]

To respond to a few of the responses below:

BTDC vs. ATDC - I'm fairly sure that this is BTDC, noting that as the marks on the cam pulley pass the marker on the engine I stop when there are 1.5 marks before hitting the last one - which I presume to be BTDC. (presume being key here).

On the position of the distributor rotor when at 8deg BTDC. On my car the #1 position is about 4 o'clock when standing on the (US) passenger side of the car and looking down on the distributor.

I did remove the carbs, completely disassembled, and noted that they did not seem to be well adjusted (below). Of course, I reassembled and now one of them leaks out of the jet adjustment screw. So I *hope* that a new o-ring will help that.

Still could not get it to fire. Once I get the carb sealed up again - I will hit it with the strobe to see if I have strong spark. I did not set up the pertronix - but noting that it did start the day I picked it up (although on 2 cylinders), then I don't know what's going on.

-M

 

[Acollin]

You say your motor "sort of ran" on at least 2 cylinders. Try to describe what what you mean by " sort of ran" and how do you know it was running on two cylinders? Do you know which two?

Reminder: gas fouled spark plugs will not fire off.

Andrew

 

[Tom H]

If #1 wire is at 4:00 position I think the oil pump drive is misaligned. It's not difficult to rotate the dist, as has been done in this case, to get the firing point correct, but it leaves the rotor a bit off (about 15 Deg) from the correct pointing orientation (Because the teeth on the oil pump gear are an odd number and the spark plug positions are an even number you cannot achieve factory alignment of the rotor with spark wire positions). This may cause weak spark, as the high voltage may have to jump a larger gap from rotor to plug wire. In addition, if the coil is using a ballast resistor, but the "Ballast bypass" wire is not in place, you may have an even weaker spark.

Tom

Edit: Ignore my comment about the rotor being off by 15 Deg. I do believe the oil pump shaft is misaligned, but it is easily corrected by rotating the distributor as I believe has been done, with no problem.

 

[RootesRooter]

I go with Chazza's advice. Starting fluid a cheap, crude, but effective way to instantly tell if you've got spark or if the timing is grossly off.

 

[mferris]

For anyone still following along - got it started tonight!

I had confirmed that even with starting fluid it wouldn't fire, so I messed with timing until I go nowhere and confirmed with an induction strobe that #1 was firing at least where the marks on the crank said it should (1.5 marks BTDC).

Then I then just put in the $8 in plugs I bought on a whim with the fluid. Fired up on the first try after installing the poorly gapped plugs.

Apparently I need to learn what fouled plugs look like.

Running:
https://www.youtube.com/watch?v=VmMJCMUtoaE

Now onto why it was fouling.

I did attempt to rebuild the strombergs last weekend and during disassembly found that that the shaft that the front jet fits into was not fully screwed into the carb - I can only presume that the mixture was too rich? and fouled at least the front two plugs. Don't know why the back two were fouled too. But could have been poorly adjusted as well.

When I reinstalled the carbs - I adjusted them to the 2.5 turns and made sure that they were synched per WSM and that the choke pressed on the throttle for cold start when pulled. For a novice, I found that using the WSM was pretty easy.

I only ran it for about 5 minutes (neighbors love me at 10pm) - but in that time it smoked quite a bit out of the exhaust. I don't know how to tune the carbs beyond what I see in the WSM - so I'll start there this weekend hopefully before I foul the plugs again. I presume with too much smoke - then I need to lean it out.

In the course of this I did get a complete setup for a Weber DGV, I guess that might keep me from fouling it again - but I do like the concept of having a 47

Overall - I'm tickled - thanks for your pointers.

-M

 

[Jay Laifman]

While a rich mixture can foul plugs, what are your rings and cylinder walls like? Could it be that you are pumping a lot of oil in there?

 

[mferris]

I have no idea about rings/cylinders. All I know is that every cylinder is at 150psi or slightly greater. I presume this indicates some degree of health. I guess I could look at doing a leakdown test or is there some other way of testing rings?

 

[Bill Blue]

I have no idea about rings/cylinders. All I know is that every cylinder is at 150psi or slightly greater. I presume this indicates some degree of health. I guess I could look at doing a leakdown test or is there some other way of testing rings?

No. 150 or slightly better in all cylinders means all those things are fine.

Bill

 

[Acollin]

Leak down test and all that sort of stuff is probably more complicated than you need to go for now based on what I saw in your clip and what I've read in the thread. I believe in moving from simple to complex. Don't worry, you will get to tough mechanical problems, but I recommend you look to the easy fix things first.

As the one who suggested the fouled plug theory and given how it started right out of the box with clean plugs, you may simply be looking at little more than jet / throttle screw adjusting. You will need a rubber hose for listening, a dime for moving the jet up and down and a longish screw driver to reach the throttle screws. I of course cannot speak to what happened during your carb rebuild, but they seemed to be a reasonable setting in the video.

Your motor sounded pretty good-- nice steady idle, but when you flicked the throttle, the response was slow and a bit bogy. This could mean rich, but I found on my 66 alpine with stroms, it meant lean. Mine were not getting the gas it needed to do what I asked of it.

The smoke could be a more serious issue, but 5 mins of run time does not even warm my car up. The smoke could be caused by a build up of crap from trying to start it for as long as you did. It could simply burn off and run clean.

Smell the oil-- if you smell fuel, change it-- filter too. Fire it up again and let it run. If it is drivable take it for a spin and enjoy your success.

You need to be able to run it long enough and hard enough to get a good read on the spark plugs. Let the plugs tell you if it is running rich or lean and adjust using the WSM.

Good luck-- think simple-- these cars are designed pretty well and while some reading this don't like stroms and have made changes, it seems to be a pretty good system-- a bit more finicky than some be pretty good all the same.

Andrew

 

[Greggers]

I only ran it for about 5 minutes (neighbors love me at 10pm) - but in that time it smoked quite a bit out of the exhaust. I don't know how to tune the carbs beyond what I see in the WSM - so I'll start there this weekend hopefully before I foul the plugs again. I presume with too much smoke - then I need to lean it out.

I'm not suggesting that this is what you've got going on, but on a previous set of Stroms, I discovered that when my car sat (overnight, for a day, for a week, whatever), some of the dashpot oil, mostly from the back carb, would leak down into the intake. It caused quite a bit of smoke during warm-up and certainly did bad things to the plugs.

While balancing and tuning, I've used Colortunes with some to much success. One thing I discovered is that the manual's 2.5 turns of the jet adjustment screw could be wildly inadequate (sometimes it's too much, sometimes it's way too little). That said, when using Colortunes, I lose count (1/2 turn up, 1/4 turn down, 1/8 turn up, etc.), so I just twist it until I'm happy with the bunsen blue color of the combustion. After my most recent Colortuning, I feel good about the way my plugs look, a nice tan.

Incidentally, I'd say your car runs pretty sweet, and I bet your neighbors were quite happy to be lulled to sleep by that exhaust tone.

 

[RootesRooter]

If it hasn't been run for a while, the carbs could easily be gunked up, even if was otherwise well-maintained. Specifically, the needle valves that regulate fuel flow into the float chamber. Start it up again with the air cleaners off and look down the throats. Lift the piston a little to get a good look. Instead of just a spray from around the needle you may see a constant small river of fuel, which is the tipoff that the needle valves need replacing.

Plus, on the puff of smoke on the video, could you have a leak from the rear carb?

Also, if your throttle shafts are worn and let in extra air, they will run rich at the standard 2-1/2 turns. Colortune is a big help.

 

[mferris]

Thanks for the pointers.

I have run it for about 25 minutes around the neighborhood. Only once did I get a backfire/puff through one of the carbs. It is still smoking out of the tailpipe although you have to look at the tailpipe to see it. I the process i have turned the jets on the carbs about 1.5 turns clockwise (in) and have noticed that idle accelerates slightly with each quarter turn on the rear carb. Although there is still some smoke I can only presume it is still rich. I took the plug out and they were black with soot.

There is not really any hesitation off idle and I haven't gotten it past 25 mph but have tried to rev some. (Which is when the backfire happened).

When it is warm I noticed it is harder to start. I though it was gunk on the plugs so I parked and came back 2 hours later expecting it to be hard to start but it started on the first bump unlike when it was warm.

I'll look for colortune or another solution tomorrow but presume I will have to do something with the carbs. I might just see it I can throw this 32/36 on if it is easily reversible.

 

[alpine1963]

Hey Mike,

Keep up the good work! I am excited about you giving this car a fresh life! Let me know if you need any parts, I still have that parts car!

Cheers,