So I got a killer fathers day present this year from my wife and 3 little kiddos. A 1951 GMC 228 1/2 ton 102-22. Engine tunes freely but has not been started in over ten years. Got it towed here and my two bother in laws, (one a mechanic and one a car guy former mechanic) have both tried to get this started and we can't. Engine freely spins. replace new battery (6Volt Neg Ground system), replace coil, distributor, wires, plugs, rotor, condenser, and points. It will turn but sounds like not enough juice to get started. Told me next step to get a new starter but I'm feeling they are just telling me to buy parts. Any ideas what this may sound like. Again I am NOT a car guy this is a huge project for me and I'll need SLOW specific instructions. THANK YOU IN ADVANCE
Your GMC came with a positive ground system but since you have replaced the coil with I presume a negative ground one it should work. You need three things for an internal combustion engine to work---fuel/air, compression, and spark so let's start with spark. Do you have blue spark at the end of the plug wire. It will be a little orange if turning real slow but should have some blue to it. Next, check the compression; should have at least 80#'s. If below 70#'s on any cylinder(s) then pull the valve cover and see if all the valves are opening and closing. Also squirt several squirts of oil in each plug hole, spin over, and recheck compression. Worry about fuel last since you can prime the carb to get some kind or reaction in starting. I have an empty quart oil plastic bottle with a 1/8" hole drilled in the cap that I can squirt the right sized stream into the carb to keep one running. If you have spark, compression, and fuel then what we do is take the wire thats on the starter along with the battery cable OFF. Put a 12v battery in the battery box and set the 6v battery on the floor/running board/fender and run two jumper wires---one to a good ground and the other to the wire you took loose frome the starter. Now the starter will spin the engine like crazy but it won't hurt the starter if you don't keep grinding for a full five minutes at a time. The wire now jumpered to the 6v battery feeds your ignition and gauges without any harm being done. Don't let your brother-in-laws back near it.
Welcome aboard enjoy the ride while here. Look up some of Nate's old posts on starting an older engine, good luck
Re - Awakening Stop mucking about and start again at the beginning : Do a valve adjust then clean the points and gap them to .012" to create a hotter spark then set the timing , try again . Like Evan said : you need the magic triangle : fuel , spark and compression all at the same time and in the proper secquence or it will never run . Soon this old Jimmy's L O N G Motor will roar back into life and your adventure will begin .
If any of the terminology or procedures seem murky don't hesitate to ASK. I know how you feel because without fail when someone tries to explain a computer procedure to me they immediately will use a term I guess even unborn babies know but I DON'T. It has to start with " plug the pronged wire into the wall outlet" and then slowly procede from that point.
Ok so now what. OK so I haven't been able to test the compression yet. I have my one brother in law loaning me the tool thingy to do that. But I tried the spark test and there is VERY little spark coming from the wire. When I try it with the plug I see Nothing. What Next? Thanks for any and all help. I could remodel a house but when it comes to cars I have always relied on others and they are not being too helpful now so I have to bug you all. We did change it to the Negative ground I was told all I had to do was switch the wires on the Amp Gauge, switch the wires on the coil and then the battery wires. Should I have done something else? How do I get spark? or a bigger brighter spark.
Your slow turning starter may be pulling voltage away from your ignition system so lets test for that. Pull the coil wire from the CAP and hold near a good ground. Turn the ignition switch on and the open and close the points with a plastic handled screwdriver, don't try to be precise just rattle them around. If you now have a nice fat spark then your losing voltage. Once again, a 12v battery hooked to the starter only and your 6v battery hooked to the main feed wire will almost certainly fire it off. We have old trucks with real bumpers so it's easy to push start one since this has all the voltage going to the ignition and zero to the starter. Once started with either 12v or pushing then they will usually fire on 6v from then on.
Hi Evan Ok so I hooked up the 12volt battery and the 6 volt. The engine turned much faster and we almost got it started with starter fluid but now when I press the starter button I get nothing. No sound engine movement or anything. Did I fry my starter? Damon
Sounds like you may have over used the starter with the 12V, or you may need to clean some terminals. Do you have an extra solenoid handy? May have to pull the ol’girl around the yard for a spell. ?’s, from a forum list I have for my tractor, they work on gas engines. Did you put gas in the fuel tank? Have you changed the fuel filters? Have you checked to see if gas is getting to the carb? Do all the visible components in the carb seem to be working when you move the linkage and gas sprays into the intake? Also; Depressing the clutch when starting does reduce starter drag especially when using thick tranny oil or in cold weather. If you forget and leave the ignition key on and the points just happen to be closed when the engine stopped turning, the chances are about 99% that the points are burned up. If you are very unlucky, so is the ignition switch and perhaps the coil. Turn the key off.
Did not realise that a 51 GMC had a push button starter. The 6v starter with a solenoid on my 37 Buick has worked without problem for about 25 years and the one on my Ross forklift has been working on 12v for 50 years but we usually have to replace the 6v solenoid with a 12v one on cars with fender mounted solenoids like Chrysler and Ford. The starter stays 6v. To bypass the solenoid and test the starter run a heavy jumper from the battery to the flat wire that sticks up out of the starter case that has a screw through it into the solenoid. This spins the starter only and doesn't engage the flywheel teeth. If it arcs alot and doesn't spin the starter motor then it's bad. If nothing happens double check for a good ground---one straight from battery to starter is best. If nothing happens after grounding good then there is an open in the windings. The slow turning on 6v and working just briefly on 12v makes me very suspicious that the starter has been bad from the get-go. Before trying anything else run a jumper from the small terminal on the solenoid to the battery. This bypasses all the wiring and switch so those can be eliminated. If there are two small terminals on the solenoid try them both as one is a bypass to the coil and will do nothing, help or harm, but the other should engage the starter. Old timers usually just use a screwdriver blade between the battery terminal and the solenoid terminal to kick the starter in while setting valves or gapping points.
No push button starter. Mine doesn't have a push button starter. Just the floor button. That's what I meant sorry
More help So I got a new rebuilt starter and it turns again. Now lets go back. Should I try the 12volt battery thing and 6volt battery. I tried with the new starter and the 6volt battery and it will definitely turn just not starting. do I have to do something with the fuel pump to make sure that's working. I need some advise on which direction to go. Again this has the standard floor pedal or button not a PUSH Button as I confused about earlier. Anyone live near Elgin IL and want to just come start this for me????
Before when you tried to start the truck, did you prime the carb with some gasoline before trying to start the engine and then closing the choke? Did you put gas in the fuel tank? Have you changed the fuel filters? Have you checked to see if gas is getting to the fuel pump and carb? Do all the visible components in the carb seem to be working when you move the linkage and gas sprays into the intake? If you are going to try and use the 12V battery again, do not keep your foot into it so long.
Look down the barrel of the carb and open the throttle all the way. You should see a squirt of fuel shoot into the intake. If not, you may need to clean your carb and /or rebuild it. But first check to see if it is getting gas from the pump. Take off the line going into the carb and have someone turn it over....Don't point it at anything you don't want to get gas on, as it should shoot out with a little pressure. If nothing here, check before the fuel pump. Take the line loose going INTO the fuel pump, see if gas is coming out. This will be gas gravity fed from the tank. If none here, put some gas in the tank. If still no gas, check the fuel shutoff petcock under the cab where the fuel line connects to the tank, if your truck has one. Still clogged? you may need to remove tank and clean or replace. If there is gas at the pump and none pumping out, you need a new fuel pump.
Thanks Guys I will try the fuel thing this weekend and advise on my findings. You guys are so super helpful and a life saver. I feel like when I ask my brother in laws they either want to take it over themselves or not do it and they don't want to take the time to figure out what works and what doesn't I guess they are spending my money so they figure buy everything new. Thanks for the help. I do have a new gas tank I have to install. Have to figure out the whole gas line thing to see if I need to replace the lines or not.
No Start Yes ; the folks here are not only very helpful but , they know everything , even the most mundane question . When approaching a long dormant engine , you need to do things in the correct order , failure to do so wastes time and effort & kills off the fun . Forget the brother in laws , this is simple stuff YOU can learn and what;'s more , you'll do a better job of it because you care and won't rush the job .
THese trucks aren't complicated....Like a tractor with a cab. They are designed to be kept running with a minimum of tools and servicable in the middle of a field. Once you determine you have gas.....to the carb, check out the spark issue. Don't go monkeying around with other things until you make it run, so you won't wonder if something you did screwed things up. Set the points with a screwdriver and a feeler guage, like Nate says. Pull a plug, or use a spare connected to a plug wire, hold the electrode end against the block and crank over. You should see a decent spark. If not, make shure you have power to the coil, also check that the coil wire has spark. If you have spark and fuel but no running, check timing, set the pointer to the ball on the flywheel, make shure the #1 cylinder is at TDC...with the valve cover off, watch the rocker arms....as you turn the engine, the intake valve will open, then close, the pointer should be on the ball. (Top Dead Center) If you continue to rotate, after a half turn the exhaust will start going down. Set the distributor rotor so it points toward the #1 cylinder (literally...at the cylinder) Now set the cap back on and the pole that the rotor is pointing to is for plug #1. Now install the wires in firing order and give it another try.
Learning by doing is my motto ! But i am always happy to be able to look in some of the good manuals and books that are availeble on the trucks subdjects. Yes these trucks are easy to work on if you have a minimum of experience and some mechanicall scales but a lot of people start from scratch when they have reached there adult age. But it is an litle adventure doing " the thing" . Restorers get emotional overwelmed by there own effords as a lot of dopamin produces in there heads. The "sensation seaker" type like my son is allways in the need of speed and would have build his truck in a different way then mine " the old guy". He would prefer all the shiny stuf you can buy, a V8 engine and wanted racing it on the track and there is nothing wrong with that. Man we are so different but allthough so alike ! This is what makes building a CHEVY or GMC truck in your personall style so genuine and makes your litle dream come true when the day comes you can show the rest of the world what you have acomplished. By the way remember the book of "Zen and how to learn to repaire your own motorcycle " ? I would read it again after so many years allready ,getting old while overhauling my truck. In the shop they have all the truck manuals , repair books and historicall litrature you probebly want , i have been collecting basic stuff i need but its the brain coorporating together with the hands that does the job. I `ll hope you get greasy hands many times and after haved washed your hands you`ll think oyeah what a f.... good day it whas Good luck and keep up the spirit Martinius.
