Hey guys how are ya? I was given this web site from a dedicated camaro enthusiest who claims if no one here can help than I should sell it! I realize this is a camaro site, but I am desperate. I have a 1974 chevy 1/2 ton 4x4 that will barely crank. The engine I just rebuilt, The starter and battery are new I have gone over every inch of the wiring with a meter. Funny thing is even when I try a different battery, (I use jumper cables from another vehicle w/out the engine running) I get the same result unless I actually start the donor vehicle and then there seems to be enough umph to crank and start my 350. I didn't raise the compression and it ran great for months on the old starting equipment. The only thing I can think of is during the rebuild I swaped the standard ignition out in favor of an hsi. I was unsure where the best place to draw power for it was. Any particullar wires I should avoid? I will admit I had help with the electrical portion of the project and am second guessing my buddy. Thanks for any info you may have I certainly appreciate it. P.S. anyone know where to obtain a free wiring diagram online or elsewhere in my area.P.P.S. The solinoid pulls and holds just fine every time, it just don't want to crank it!!!

I am not sure about the 74 trucks but the cars with points ignition systems had a resistor wire for the ignition system that has to be replaced with a 12 gauge wire from the fuse block to the HEI. That is what the problem sounds like. Sometimes the resistor wire doesn't even allow enough voltage to turn the motor over at all. Again I am not that familiar with the Seventies trucks with pre HEI ignition. I am sure that if I am wrong, someone else will chime in and set us both straight. Good Luck.

Make sure you have all the ground straps from negative to body/engine, body to chasis, and that all are in good condition & connected to a clean surface. Using a volt meter, verify that you're getting full 12 volts at the solenoid when starting the engine. Also find a good 12 volt supply for the HEI ignition, if it was installed to replace a points type ignition. Also clean the positive wire connection from the battery to the starter. I have a 30 amp relay installed in the ignition wiring to make sure I get full 12 volts at the solenoid every time, just to be safe. ;)

Sounds like you're loosing voltage in the electrical system somewhere. When you said you checked everything out with a meter, what did you check? Did you measure between battery posts and battery clamp, battery clamp and battery cable, battery cable and cable termination etc? What this does is measure the incremental voltage drops accross potential bad connections. Orench mentioned grounds. This same technique should be applied to your ground circuit. Measure post to clamp, clamp to wire, wire to termination, termination to block, block to starter etc. If you find anyplace where more than 1 volt (I'm throwing numbers) drop is found, you've located a bad connection. One common places is where the battery cable is crimped on to the battery terminal.

As far as HEI goes, you do want a full 12volt and breaker point electrical systems usually have a resistance wire to feed the ignition as mentioned. However, it would have no impact on cranking. When the engine is cranked, 12volts was supplied to the ignition coil from the starter solenoid estially bypassing the resistance wire. This gave a hotter spark while cranking. Never the less, even with that wire missing, the engine should crank although it might not start.

-dnult

You didn’t put the 1,3,5,7, pistons and rods in the 2,4,6,8, holes did you? They don't roll over easy when that’s been done, don’t ask me how I know…

are there any differences between pistons 1357 and 2468???

No, but when you stick them in the wrong hole, the rods are on the wrong side and bind.

Notwithstanding all of these other questions by the masses, I will go for the simplest thing.

Since you replaced the ignition, try pulling the coil wire while cranking. If the engine turns over at normal speed (and I think this is what you are talking about "cranking slow") then the ig timing is tooooo advanced!

Just an idea?

How easy is it to turn the engine over with a breaker bar and socket on the crank pully bolt? Was the engine bored? Were the crank and rod bearing clearences Plasit-gaged?