VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1928 chevrolet truck

Hi, I own a small restoration shop in Auburn Hills Michigan. We are currently wrapping up a full restoration on a '28 chevy truck. I'm looking for some feedback out there. The truck has an orignal and correct rebuilt engine installed but for the life of us we cannot get it to start and run. It is still 6 volt, has the orignal '28 ROKX-0 carb which has been rebuilt, new points set to spec, original vacuum fuel pump etc. Its getting spark and its getting fuel but will not start. There was a brief period when it would run off of a prime in the cylinders but even now it doesnt seem to want to. We install a lot of different engines in the cars we restore so we have a lot of experience. Some are much older and more exotic but never have we experienced an engine that refuses to run despite getting fuel and spark. We are overlooking something simple. Anyone out there have any insights to this particular application. We're all ears.

Have you verified that there is spark at the spark plugs? If so then squirt a little carburetor cleaner or starting fluid into the air intake of the carburetor and try to start it. If it runs for a short period then remove the bowl from the carburetor with a catch pan under it. How much fuel drains out? A cup? More? or Less?

Hi HydeAutoBody,
I live in Romeo, MI and have an 1928LP Capital 1-ton. If you have spark, fuel, correct firing order, timing and compression, she should start without issue. There are some tricks to isolate the issue but these engines are fairly simple. If you still have issues, let me know and I might be able to drop by and have a look.
Best,
Paul

I've encountered the following problems on my '28:

1. The previous owner put the flywheel on incorrectly. The flywheel can be bolted on in any one of six different positions. It was 1/6 off rotation so the timing marks did not indicate TDC. I took the oil pan off, physically verified cylinder 1 was at TDC, and then painted a new line on the flywheel that lined up with the pointer in the inspection hole.

2. I found a deteriorating piece insulation between the distributor body and the loop of the spring metal going to the movable point. I suspect this was allowing the movable point to touch ground occasionally. I used a thin piece of cardboard (manila envelope) and made a new insulation strip.

3. Timing is critical. With the spark lever in the fully retarded position (pulled down toward the driver), the points should just start to open to provide spark to cylinder 1.

Here's my procedure for starting my truck:

1. Make sure the transmission is in neutral.

2. Turn on the gas valve at the bottom of the vacuum tank. If the truck has been sitting for a very long time, I occasionally have to prime the vacuum tank. I installed a 1/8 NPT plug at the top of the inlet line for this purpose.

3. Fully retard the spark lever.

4. Pull the throttle lever down (open) a bit. Something like 3/4" to 1" down.

5. Turn on the key.

6. Pull and hold the choke out.

7. Do not press and hold down the clutch pedal. Now, step on the starter button.

After the engine starts and runs for a few seconds, I ease off the choke and slowly advance the spark until the spark lever is in its top position. Then, usually, the engine is running faster than I'd like so I back off the throttle lever, but still leaving the engine running at a fast idle.

After a few moments, when the engine sounds like it is running smoothly, I'll push the throttle lever all the way up so that the engine is idling correctly (500-600 rpm).

Hope this helps.

Cheers, Dean

i agree with this, it screws up alot of re-builds:

1. "The flywheel can be bolted on in any one of six different positions. It was 1/6 off rotation so the timing marks did not indicate TDC. I took the oil pan off, physically verified cylinder 1 was at TDC, and then painted a new line on the flywheel that lined up with the pointer in the inspection hole."

Not sure what was all done to the motor but the service manual is wrong for the timing procedure of the cam, and many aftermarket cam gears are mis marked...did you put in a cam or cam gear or removed the cam even?

Hi Paul, nice to meet you. Everyone has been so nice in offering suggestions. A few times it has fired off a prime and run for a short period and other times we cant get it to hit one lick. There is something we are overlooking. Two things we have not done is check compression since our gauge doesnt fit this engine. The second thing is check the timing mark on the flywheel. We did bring it up on #1 and checked the valves to ensure it was up and then checked rotor position. Paul, if your receptive to working along with us here one afternnon we'd love to have you help flog the truck and get your opinion on what we've done. We would pay you of course. This truck is a former heavy duty farm truck. It's a Captital but probably a bit larger than your 1 ton. Let us know.......

Just a suggestion on the pressure gauge, I took an old spark plug and crushed out the porcelain so that i could use the spark plug base as the correct hole size for my pressure gauge.

Hope that helps

That does help. I thought about doing the same thing then just using the rubber fitting on the gauge to mate up

HydeAutoBody,
Nice to meet you too. I can arrange to stop by and take a look. Payment is not necessary, as it's the enjoyment of working on these gems that makes it all worthwhile. Give me a call and we can coordinate a date/time. I have a few days off work scattered over the next few weeks. My number is (586)531-5041.
I look forward to the challenge!
Best,
Paul

Sorry for the late response Paul. Busy time at the shop right now. We did a compression check today and got about 50lb straight across but the engine is new and the rings will need to seat. Thanks so much for your offer to help. There is some thing there that fresh eyes will spot. I'll call you from the shop tomorrow and we can chat.....Rob

UPDATE! Paul was able to visit and help us out (thanks so much Paul). He was able to determine that the rebuilt original carb was not allowing the fuel to be drawn into the manifold so a temporary model A carb was installed. The cylinders are getting fuel now but the engine is still not running. The spark appears to be weak from observation. Now that we're getting fuel perhaps starting from the very beginning with timing and such is in order.

Rob,
I am glad it is getting fuel now. I have been thinking about it since I left. I believe you are right and that you need to go back to the basics and start with timing, wire wires not suppression wires, and make sure the ground is very good. The engine has to run, as you have everything else, compression, etc.
I also looked and the engine should be retarded to half position for starting, per a manual I have. Not fully retarded. Worth a try once the timing is verified.
By the way, they do use a wire for the choke hook up.
Best,
Paul

Hello,
You mentioned a full restoration and the spark appears weak by observation. By chance are you using the original ignition coil? If so, I would suggest trying a 6V coil and condenser from something like a '54 Chevy and adapting them to fit. The original coils are not very reliable today.

I was having the same type of problem with a '28 speedster that i am building. I was able to get it to run (at times) for a minute or two then it would die. At times i was able to restart it with starting fluid, other times nothing.

So I went all out:

1) Rebuilt carburetor - by a fellow VCCA member
2) Replaced spark plug wires making sure they were made with wire core
3) Replaced points, coil and condenser with new parts
4) Made sure that all vacuum connections were tight
5) Made sure i was not grounding out from the coil (-) to the points, replacing the wire connection between the coil and the distributor
6) Pulled out distributor, pulled #1 plug, made sure i was at top of the compression stroke, set spark lever, reset the distributor
7) At this point I discovered that I the flywheel was installed incorrectly so when i was at top dead center I remarked the TDC on the flywheel and counted the teeth to make a new 25 degree mark
8) made sure the vacuum tank was full of fuel and that i had gasoline in the carburetor fuel bowl
9) adjusted valves (cold)
10 tighten everything down and it fired and ran
11) became a happy camper again

I am not sure what item or items made the change but after chasing one item after the next i just started from scratch and trusted none of the items that i had worked on before.

I'm late to see this due to other priorities, but haven't seen a resolution. I used a 6 volt Echlin IC7 6-volt ignition coil from Napa Auto, and a 6-volt condenser across the points. The other recommendations above here look great. When we first tried to start my '28 we didn't connect the condenser correctly. We pulled #1 cylinder plug and made sure the timing mark was visible with the head of the piston all the way up. We used a gas can and rubber hose as in an IV to provide gas temporarily. As soon as we connected the condenser correctly, she started right up and ran flawlessly. On reconnecting the regular fuel line from the vacuum fuel unit/ pump, we started her up again and she continued to run great.

That's great. Sometimes a little error can produce a GREAT deal of frustration.

you were right about the tube for the low speed idle. It was broken so sent the carb to Bob Clark to have a new one installed. Carb is installed, engine shows to receive fuel, we have a spark, Double checked firing order and point gap and still wont fire up. I'm really baffled on this. I have never had an engine that I couldnt get started. I'm overlooking something....but what??

If you squirt a little carburetor cleaner into the carburetor air inlet does the engine fire? If not are you 100% sure you have spark at the plugs? If there is properly timed spark and fuel/air mixture approaching 1:15 and the mixture is compressed the engine should fire.

we have spark and good compression. To me the spark looks weak but it is there. I'm stumped on this one. It does have supression wires on it and I'm wondering if solid core wires would improve it. If you spray carb cleaner or starting fluid it does a little attempt at starting but nothing really to speak of.

Yes, solid core wires should fix your problem.

carbon core wires are well known to have problems in the low coil voltage systems. Modern ignition systems produce 60,000 volts that will jump large gaps. The older systems might get to 25-30,000 volts at the spark plugs. Any plug wire loss means weak spark at the plug. Use only solid wire spark plug wires.

We all look forward to hearing that your truck is running smoothly, after such an unusual problem arose. It's been a long winter, and winter's not over here in western NY.

We purchased a new reproduction solid wire set which produces a brighter, stronger looking spark to replace the supression core wires and despite getting fuel and spark its still reluctant to fire yet. We're really stumped on this one.

Didier asked if you changed or removed the timing gear? I thought it might be worth asking the question again... 1927 & 1928 Valve timing is different...

A machine shop out east was advertising in Hemmings that they were selling some vintage engines and happened to have a 1928 Chevy engine for a truck we were rebuilding. It came fully assembled with all the accessories. Initially we were able to start it briefly but it hasnt run since despite having spark, compression and gettng gas. We brought it up on #1 and the timing mark on the flywheel corresponds with the pointer. Really a mystery to us!