Sbc won't start think I checked everything??

I'm going nuts getting a buddies sbc started tonight. Ive wired up a ton of these motors and got them running perfect but this ****er just wont fire up. Maybe i missed something? I wired up the ignition then put all new plug wires, coil, and points on. I checked and tdc is on the #1 cyl. Rotor facing that plug! Triple checked my plug wires to the right order. I'm getting spark to the plugs just fine. Plenty of fuel. First ***isted with starting fluid. So I turn it over and it seems like it's gonna fire but then backfires a little. Maybe Im tired today??? Any suggestions.

 

sounds like the timing is a little off. try rotating the distributor a little.

 

Is the dizzy on 180 out? That got me not to long ago..

 

Check to be sure you are on the compression stroke. Sounds like either one tooth off or wires crossed.

 

distributor out 180 degrees? common error

 

Did the motor run before or has it just been rebuilt? Probably something simple. Are you sure #1 was at TDC of the compression stroke and not the exhaust stroke? Just throwing out ideas. If you didn't put it together yourself, maybe the cam timing is 180 off? Not implying you don't know what you're doing, just making suggestions.

 

sounds like timing, does it have a good carb

 

Was it running before, or is it a new build?

 

When a Chevy its on TDC #1 compression (ready to fire) the rotor actually looks to pointing towards the #2 cyl (towards the left front of the engine looking at it from the front of the car).
How do you know it is on the TDC compression stroke. Did you use a piston stop?

 

Something similar happened to me when I wired the distributor cap 1,8,4,3,6,5,7,2. I had that sequence commited to memory. Only thing was , I wired it backwards or counter clockwise. After a few backfires I figured it out. Good luck.

 

Rocker arms to tight, cranking speed ok, skipped timing chain, are a few other things but hard to tell without more information. With points could be bad condensor or little ground strap on points mounting plate.

 

Did you happen convert the distributor over to a Pertronix unit and to forget to byp*** the old ballast resistor?

 

The last couple of point sets I bought gave me fits: Replaced the points, set them and cranked the starter: no start. Checked everything, including resistance at coil, coil voltage with coil tester, and condensor, with same coil tester.

(engine ran when I shut it off, so I turned it over by hand, looking for jumped chain on broken cam sprocket...it was O.K.)

Finally, I dragged a folded piece of #600 sandpaper thru the points, in closed position...
Bingo! Started right up.
There was a film of some sort on the point faces, probably to ensure that they didn't rust during shelf life. They were Delco-Remy. (D-106p)

 

Fire to the plugs-yeah=OK/next=change the plugs-most SBC gas fouls em bad

 

I helped a guy who had a problem getting a small block running....when we checked the compression, there wasn't any.

A few years later I helped the same guy getting a different small block running...no fuel getting to the cylinders, it was EFI and all the injectors were plugged from sitting.

I helped another guy get a small block running, he did everything to it several times, I checked that the timing was right, getting spark, etc. then told him to buy buy 8 new spark plugs, he did and it fired right up.

Could be anything.

 

whats your method of checking TDC, i stick my finger in #1 when rolling it over by hand, the exhaust stroke can fool some times.

 

I installed an MSD unit with a guy once, and we spent hours trying to figure out why it wouldn't run--we had power everywhere, it'd crank, but wouldn't light.
Turned out we tapped into a wire that was hot when the key was in the "RUN" position, but went dead when the key was turned to the "START" position.

An old guy once told me that 90-percent of all fuel problems are ignition, and I have yet to prove him wrong.
-Brad

 

advance the timing by rotating the distributor CCW about 10-20 degrees. It'll probably start right up.

 

Had a problem starting one once...double and triple checked everything....fire to plugs but did what yours did, tried to fire, backfired, etc. Finally I admit to defeat and call my dad. He comes over and says, "did you adjust the rockers too tight?" Sure enough, we backed them off and boom, fires right up. Maybe give that a try?

 

x2 on the spark plugs fouling up , every once in awhile it would try to start but no go!! i was using a inline spark tester so i ***umed it was getting spark , triple checked everything ,points,gap,wires,tdc on compression stroke,wire rotation,rotor rotation i mean i reset everything atleast three times , and using that damn inline spark tester thought i was getting spark but it wasnt sparking at the end of plugs, i ended up putting new plugs in and turned the key and it fired right up....i always suggest new plugs on fresh fire up or if motors been sitting for any length of time

 

Thanks for all the info! I'm gonna have his cheap *** get some plugs today. I'll pull the valve covers and check the valves and rockers while I'm at it. Hopefully I have better luck. If not I'll check in for more info, thanks hamb!!

 

did you ever get this running?

 

Fuel, fire, compression make all happen when in the right order.

 

I had a similar problem with a 1932 Pontiac six... turns out I had the distributor wired backwards !! Check your rotor rotation direction.

 

Being a FORD guy I have done this^^^^^^^more than once.

 

Did you check the radio fluid?

 

I did the same thing when I built my T bucket in the early 70's because I had been driving cars with distributors that turned counter clockwise for several years. Sure pissed the neighbors off when I woke up at two in the morning with a brainstorm and went out in the garage in my bathrobe, swapped the wires an busted it right off with open megaphone headers.


You are getting fire to the plugs when it cranks but you need to know that you are getting the fire at the right time. I'd pull number 1 and bring it up on compression and make sure that the piston is at tdc and check the marks. The damper ring could have rotated and make your marks off. Once you know it is on #1 tdc set the distributor so that the points are open with the rotor pointing at the #1 plug wire spot on the distributor. Then tighten the distributor down and it should fire up.

 

if it is not a fresh build, perhaps it is just a tired old motor?

I had fits with one that was sitting a long time. Rings were stuck and the compression was so poor it would not fire and run.

while cranking, we poored a quart of ****** fluid through the carb. Let is sit 24 hours, pulled the plugs, cranked it to clear the cylinders, installed NEW plugs, poured some gas in the carb and cranked it over. Started up and smoked like hell.

after a couple of hot/cool cycles and some driving it settled down and the rings began to seat. It turned out to be a good engine.

just be sure you use straight SAE oil, not multi-grade with detergent. Makes it harder for the rings to seat.

good luck!

 

I did get it running good! It was one click off On the distributor and I put new plugs in, then put new fuel pump and she runs great. Thanks for all help hambers.