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08-13-2021, 01:07 PM | #1 |
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What am I missing with getting this 235 running
I picked up some gas and a battery and... nothing. Just turns. No sputters, not even trying!
What I've done so far: Compression: Confirmed that I have compression (110lbs on Cyl 1) Static Timing: Confirmed that at TDC, with both valves closed on the compression stroke, the ball on the flywheel, the rotor is pointing at cylinder 1 and the reluctor on my HEI is lined up with a .007ish gap Spark plugs gapped to .45 for HEI 0.6 Ohm cap Suspecting my HEI conversion may be trouble..So I switched it back to points, borrowed a known good gap from my gmc, installed at distributor TDC, confirmed point open at TDC and rotor pointing to cyl 1. No change. Spark plug #1 removed with wire attached, grounded to cyl head and cranked, getting spark. Fuel: Fuel filter is full of clean, clear gas. Loosened fuel line at the carb inlet, fuel comes out. We are getting fuel, pump is working. Tried starting fluid Compression and Fuel are dumb systems, so I suspect the culprit is my spark somehow. Yet I've read time and time again that static timing at TDC should at least get you running rough and you can go from there. What am I not checking? Getting this running will really help boost the morale to finish this truck up and get back to my others.
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08-13-2021, 01:30 PM | #2 |
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Re: What am I missing with getting this 235 running
Check to see if plugs are wet or dry after cranking. Also make sure plugs are not carbon fouled, covered in black soot, and that gap is ok. Wet plugs indicate spark is not occurring. Dry plugs tell you something else is probably happening. If the carburetor needle is stuck closed or plugged then fuel can't get into the carb. Does pouring a little fuel into carb make it sputter? Or starting fluid? It's also possible that it will want more timing than 0 to start. Not usually but sometimes...
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08-13-2021, 01:37 PM | #3 | |
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Re: What am I missing with getting this 235 running
Quote:
I've pulled a plug and it was clean and relatively dry I suppose, although I didn't hold it up to the light or anything. I'm sure timing may not stay right at TDC, but I've been told that it should get you going at least, so you can fine tune from there... I guess there's not much to lose by adjusting the timing way out just to see what happens
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08-13-2021, 04:19 PM | #4 |
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Re: What am I missing with getting this 235 running
fuel, air, compression, spark (at the plug), firing order. check for those items. then check timing.
was it running before the pertronix? if you have a timing light have somebody crank it over while you see if the timing is close, maybe the petronix timing is a little offset compared to a set of points. or dump some fuel down the carb throat, put the air filter back on in case it backfires (seen a guy burn his hair off doing this with no flame arrestor, good thing his eyes didn't get singed too), have somebody crank it over while you turn the dizzy a bit. maybe its just too far out of time to start. fuel-simply dump some gas down the carb and crank it. if the fuel is getting to the cylinder the plugs should be wet if it doesn't fire up. check fuel pump output if there is no fuel squirted from accelerator pump when the throttle is pushed quickly. air- stick your hand over the carb inlet and see if there is a pulse of vacuum. keep in mind that this will also act like a choke and tend to overfuel. compression-kinda self explanatory if the starter has to work to crank the engine, but always a good base to start with doing that test so you know what each cylinder is doing and the condition of the engine. starter load "feel" can lie spark-check for spark at the plug. should be a nice blue snap. ensure the coil is getting power when you crank it over not just when the ignition is in the "run" location. should be full battery voltage for starting and then the battery power is stepped down through a ballast resistor for running. this is to save the old points and coil life. there is a wire from the starter solenoid to run full voltage when the starter is engaged.do you have a key starter or a starter pedal? keep us posted with what you find |
08-13-2021, 05:41 PM | #5 | |
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Re: What am I missing with getting this 235 running
Quote:
I've added the fuel and it doesn't sputter. These Rochester B's also don't like when you pour fuel down them, it just runs out the butterfly shaft.. I've opened up the throttle to pour in the fuel to combat this. Nothing happens at all. No sputters or anything. Since I'm not using the points type anymore, I bypass the ballast resistor and wire coil + to IGN 2 on the ignition. It shows 0V with Key On, and powers up during starting.. these ignitions only have Key On, and Key off, there isnt an accessory/run/start. I have a starter pedal, its a 235 straight six. I moved the coil wire over to an accessory terminal that is 12v key on just to test it out and there was no change.
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08-13-2021, 03:58 PM | #6 |
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Re: What am I missing with getting this 235 running
I just noticed to .045" gap for HEI. That may be too much for points if you still have the old distributor installed.
I'm not sure if it's possible to get the timing 180 degrees out. If so you're likely to notice popping out the intake if you advance the timing. It's possible that the spark is finding a path to ground before it gets to the distributor. But your HEI is coil-in-cap while points uses a separate coil, correct? This test probably isn't needed but you could disconnect the coil wire at the distributor end and see if it throws a consistent spark across an 1/8" or larger gap while cranking. There's also the possibility that there's an intermittent wiring issue reducing voltage at the coil but I don't think it's likely. Usually TDC is pretty close but on some occasions I've had to advance timing to get an engine to start. Maybe other folks will have better ideas for you... |
08-13-2021, 05:30 PM | #7 | |
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Re: What am I missing with getting this 235 running
Quote:
I have the HEI distributor conversion modification, it uses an external coil. Should I have 12V at the coil with key on? I have it wired to IGN2, which is supposed to be for the Coil, but I only get 12V (more like 10.5) when I'm pushing the starter foot pedal. Stock, IGN2 should run to the ballast resistor, and then the coil. I'm just running straight to the coil for HEI.
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08-13-2021, 04:20 PM | #8 |
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Re: What am I missing with getting this 235 running
sorry, shouldda mentioned the "air-vacuum pulse check with hand over carb" has to happen when you crank the engine.
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08-13-2021, 04:27 PM | #9 |
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Re: What am I missing with getting this 235 running
if it sputters when you dump fuel down the carb it is still possible that the carb float inlet valve is stuck and not allowing fuel to enter the carb. you could do a pressure/volume test easily at the outlet of the fuel filter.
what dizzy do you currently have installed? points or electronic? |
08-13-2021, 04:36 PM | #10 |
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Re: What am I missing with getting this 235 running
electronic should have 6 bumps on the little star wheel under the rotor. just to ensure your ignition swap to electronic is the correct one for a 6 cyl.
dry plugs usually means not enough fuel went in to make a bang. dumping some gas down the carb usually will entice some sort of chuggle as you crank it. if it floods it usually burns that fuel off if you keep cranking until it has the mixture good enough to make a bang. if the plugs are nice and clean, like new, it can be hard to see if they are wet or not. sometimes I us a small propane or butane torch to warm the plug up and see if there is fuel that burns off at the same time. wet plugs tend to soak the fuel into the porcelain insulator and can cause a misfire (or no fire) as the spark simply tracks down the insulator. warmed up plugs would be dry, a quick sandpaper run through the electrodes also ensures a clean bright place to start a spark from. a dark area to check for spark is also kind of a must because otherwise you can't see well and may miss the spark grounding down the insulator, as well as not really seeing the quality of the spark. |
08-13-2021, 05:47 PM | #11 |
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Re: What am I missing with getting this 235 running
HEI electronic ignitions usually have a larger wire ran to the distributor because their coil is on top of the cap. your system looks more like an aftermarket electronic ignition that bolts in the stock dizzy where the points used to bolt in. they use an external coil and simply replace the switching mechanism of the points with the solid state parts. their coil wiring could be kept the same as the points because the old ignition coild doesn't know the difference what switch is being used, points or solid state, all it knows is that 12volts for extended periods makes them heat up and fail.
the reason i asked about the starter type used is because the old floor pedal starter would use a wire at the starter switch (on the side of the switch) to connect battery power to the coil when the starter is being used, then when the engine starts and the starter is released the ignition switch feeds power to the coil through a ballast resistor. engine start=12v at the coil engine run =9.5-10.5v at the coil disconnect the wire at the coil to test for voltage so you get a real reading with no load of a coil in the line. check your coil for any discoloration on the sides which could indicate an internal problem from running too much voltage over time. post up a pic of your engine bay so we can see what the heck you are running instead of individual parts. sometimes we can pick up on something you overlooked that way. check what brand of electronic ignition you have installed and how it should be wired. here is a link to the starter switch with the wire connection for the coil power on the side of the switch. that wire should run to your coil for 12v when the starter operates. https://www.classicindustries.com/sh...w-843133334189 what have you got for spark at the plug? here is a link to a spark tester tool. you could easily make yourself with a piece of wood or plastic and a couple of screws. ground one to the engine and connect the spark plug wire to the other one. or just pick up a spark tester, they are pretty cheap and work better than getting your wife to hold the wire, lol. https://www.amazon.ca/Thexton-THE404...49051670&psc=1 |
08-13-2021, 07:22 PM | #12 | |
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Re: What am I missing with getting this 235 running
Quote:
The coil is wired to the IGN2 terminal on the ignition switch, which provides voltage during startup only. Thats what I've seen on wiring diagrams.. The side terminal of the push start has a purple wire that leads to IGN1 on the ignition according to the wiring diagram. I'll check out the spark and report back
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08-13-2021, 07:58 PM | #13 |
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Re: What am I missing with getting this 235 running
Here is my HEI setup as well as the wiring on the ignition. I moved the green wire to the accessory block since that is 12v at key on, and that goes to coil + as well as supplying 12v to the HEI module. No change, but I think this is more correct for wiring.
The purple wire on the side terminal of the starter is useless at the moment, its just there in case the distributor gets converted back to points and a conventional coil is re-added.
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08-13-2021, 05:58 PM | #14 |
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Re: What am I missing with getting this 235 running
if you have a pertronix system maybe check for a wiring diagram to ensure it is all connected properly. of course, if you have a good blue spark then disregard.
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08-13-2021, 06:01 PM | #15 |
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Re: What am I missing with getting this 235 running
maybe let us know if you get a nice blue spark, then we can move on.
no sputter with a dash of gas down the throat makes me think the timing or firing order is outta whack. if you have a good spark, spark plugs, compression etc. compression readings? spark? wet plugs? |
08-13-2021, 11:29 PM | #16 |
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Re: What am I missing with getting this 235 running
cool HEI set up. have you checked the quality of the spark yet at the plug?
I gotta say, if it were me, you have confirmed fuel delivery to the cylinder, you have confirmed compression, you have confirmed a good spark at the plug, you have dribbled raw gas down the open carb throat and it won't even chuggle.I would have a buddy crank the starter while I move the dizzy to advance the timing. it should either start or get to the point where the starter catches on every compression stroke because the timing if that far advanced. if you don't have help then possibly rig up a toggle switch under the hood to simulate the ignition switch, block the wheels and confirm the trans is in neutral, operate the starter from under the hood and move the dizzy a little at a time until something happens. have you checked to see if the dizzy plug wire locations line up with the cylinders in the firing order and also on their compression strokes? it could be that the previous owner didn't quite finish getting that part of the mod completed as explained in the "how to build" link you posted. I did notice the reluctor ring air gap looked tight but if it doesn't rub it should work that way. |
08-14-2021, 09:17 PM | #17 |
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Re: What am I missing with getting this 235 running
Dave if I remember correctly the “points” on the distributor cam should be square edged and flat across the face . Yours appear rounded .
I think the air gap should be .004” The pick up wants to see the sharp edge for a strong signal . The rounded point may not give a good signal for the pick up . You should get a blue spark .
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08-15-2021, 01:17 AM | #18 |
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Re: What am I missing with getting this 235 running
Confirm spark. I had a 1955 first series that had a new rebuilt carb in it that would crank and crank. I spent a few nights farting around checking this and that, then it hit me, that new store bought rebuilt carb is the only thing I hadn't looked at. I had rebuilt the original and had it on the bench so I swapped it out in about 10 minutes. Cranked right up.
I was better at carbs than the rebuild joints I guess.
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08-15-2021, 10:35 AM | #19 | |
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Re: What am I missing with getting this 235 running
Quote:
I would only suggest that everything else sounds ok. Fuel, spark, and compression. So it might be a good idea to double check that the distributor is aligned properly. If you are working by yourself the easiest way to check is probably going to be moving all the wires on the cap. Swap 1 and 6, 5 and 2, 3 and 4. If it starts then you should plan to pull the distrubutor and re-install once your victory celebration is over. |
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08-15-2021, 02:40 PM | #20 | ||||
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Re: What am I missing with getting this 235 running
Quote:
Quote:
Quote:
Spark is definitely my challenge here. I did check compression for the other cylinders and 4 were over 100, one was 75 and one was 50, and that was after a bit of Marvel Oil in the cylinder. So either way, this engine isn't going to run great, but dammit it WILL run. I have other projects to worry about and a rebuild isn't on the menu for this truck. I don't have a spark tester yet, but I swapped it back to points, re-gapped the plugs to .035, and I do see a blue spark there when i hold the plug against the head to ground it. I don't have a spark tester though, so maybe it's not as strong as I think? Quote:
I rotated the engine with the cap off so I could verify that it was timed roughly correct, and decided that I may have been 180 out somehow. I redid that process and flipped the timing 180 again, and pushed the pedal. Flames started coming out of the exhaust manifold, which to me means maybe I WASN'T 180 out if ignited fuel can escape the exhaust valve. I should have changed to points, then tried to bump it before I changed the timing again. Some mouse droppings came out as well, and I hadn't removed the manifolds yet, so this was as good a time as any. I pulled the manifolds, didn't find nests or anything, but the gasket is now toast and I need to wait until a new gasket arrives tomorrow to continue. There was a good amount of fuel just sitting in the intake manifold though. I will follow up after I get the gaskets installed, re-evaluate the timing, and see what we get.
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08-16-2021, 08:38 PM | #21 |
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Re: What am I missing with getting this 235 running
I got the gasket today, removed the manifolds, cleaned them up a bit, cleaned up the mating surfaces and got it installed. I had a heck of a time installing it until I realized that I needed to loosen the bolts between the intake and exhaust to allow some movement.
Anywho, re-assembled, tested it out, and other than a few pops, no dice. I double checked the timing and shone a light through the spark plug hole... literally staring at the piston while i rotate the engine to be sure, and I was on the flywheel ball. I have new plugs, new wires, new capacitor, new rotor, new cap, new vacuum timing thing... the only piece that isn't new is the coil. So I ordered two and they'll be here in a week. Time to work on the GMC Cameo for a week!
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08-16-2021, 09:50 PM | #22 |
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Re: What am I missing with getting this 235 running
if you have a compression tester, which I assume you do since you have the readings, you can use that to ensure you are on the comp stroke. bring it up to top dead center and then apply some air pressure to the cylinder using the comp tester hose. there should be no air escaping the exhaust pipe or up through the intake and out the carb. the engine is gonna wanna crank over when the air is applied so be careful OR you could apply, say, 10 or 15 psi to the number one cylinder and then crank it over slowly by hand. you will hear the air escaping the exhaust pipe when the exhaust valve is open, then as you turn further the air will leak out through the intake valve as it opens, when the valve closes as you continue to turn, the engine will be on it's compression stroke next so you could disconnect the air line and continue turning the engine by hand as you watch for the timing marker. when the timing mark comes around you should be on #1 cyl ready to fire. set the dizzy accordingly and give it a try. whaddya got to lose, the finding of #1 cyl TDC ready to fire has to be done at some point. maybe the old coil still has enough life to fire it up. maybe it's still good enough to run it and you don't even need a new coil. worth a try since you're in this far.
or if you're just frustrated and need a break work on something else. |
08-17-2021, 02:53 PM | #23 | |
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Re: What am I missing with getting this 235 running
Quote:
I tested my coil with a multimeter and got 7500 ohms on the secondary winding. I read that it should be more like 11000 ohms, so that may be contributing to a weak spark. We'll find out!
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08-16-2021, 10:07 PM | #24 |
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Re: What am I missing with getting this 235 running
Dave the "Points" I'm referring to are on your conversion HEI distributor NOT the point type factory GM distributor.
Those "Points" on the Reluctor should be sharp edged and air gaped from the pickup .
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08-17-2021, 02:55 PM | #25 |
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Re: What am I missing with getting this 235 running
I see. Well those points are not rounded, it looks exactly like the image you posted. I took off the HEI bits anyhow to remove them from the equation.
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