difficulties to start engine after rebuild

[coronetcustom]

hello,
i got difficulties to start engine after rebuild. here´s the situation:
first i list eng.specs and new items i installed. 1971, 383 mopar, electronic ignition, edelbrock 750cfm carb with manual choke(new part), edelbrock performer 383 intake manifold(new part), hydraulic mopar performance 272 cam + lifters(new part), i also got exhaust set that i don´t know correct term, but it has individual pipes from cylinder head. i used "how to re-build big block mopars from hpbooks" which i have found excellent book, for all work. however start-up is getting a difficult. cam timing is correct, i used mopar perfomance dual chain, timing marks aligned ok, not retard or advance setting. i did make rookie mistake of setting distributor 180´off, i corrected it. i have right wiring order for spark plugs and #1 at tdc. so here´s what she does: 2times backfiring and flames from carb. after resetting/checking distributor and wiring i managed to get eng.running for few secs. but no real deal. carb puffs gas sometimes(i got air cleaner off). spark plug wiring is 1yrs.old from accel and worked fine before i started project. new spark plugs correct type. i tried with new and old distributor cap, no difference. gasoline is flowing ok, in fact plugs have been bit wet. i think this is timing issue which i could fix with rotating and finding right position for distributor.. or could it be that my new installed parts are not working together? maybe carburator is too big. i have 600series carter which worked fine before. any opinions or advi

[peg leg]

I had the same issue as you. Mine is a small block, but it does not matter. I found that I was lining up TDC on the damper 45 degrees off correct location. The damper has three or four different tining marks on it, and only one correct TDC mark. This caused me to install the distributor drive gear 45 degrees off. The correct mark has advanced and retarded degree numbers stamped on either side of TDC.
Your damper may not have these extra marks, but I'm betting the problem is distributor rotor location. I solved my problem by simply moving the plug wires CCW one hole. The fact that you are getting fire tells me you are close.
Let us know if this helped you!

[440roadrunner]

Troubles like these are almost ALWAYS a "get back to basics" situation.

First, how do you know the cam timing is correct? Can you assure me (and yourself!!) that the timing marks on the driveset match up?

If you have an aftermarket cam drive, that has multiple retard/advance cam timing settins, there are different keyway/marks for each setup. If you have an OEM type cam drive, there should be two simple marks--one on each sprocket.

NOTE: Most stock cam drives, when setup "on the marks" are actually 180 deg off. This means that no6 is up to fire, not no1

You CAN get some idea of cam timing by checking for "split overlap." Pull the driver's side valve cover, and rotate engine on TDC. On one rotation, both valves on no1 should be closed, and on the other rotation at TDC, both valves should be somewhere near equally open. You must use some reason here, because if you are using hydraulic lifters, one or the other may not be "leaked down."

Speaking of pumped up lifters, do all 8 cylinders have compression? What rockers are you using? Stockers? Adjustable? Any chance you have one or more valves hung open?

Are you sure you (have a diagram?) are numbering the cylinders correctly?

Bear in mind that a 383 distributor rotates CCW (anticlockwise) so make sure the firing order goes around to the left.

Here's how to check the timing marks and make SURE

Make yourself a "positive stop"
Take a plug shell, and hacksaw off the crimp next to the ceramic.

Drive the ceramic out. Tap/braze/weld theads into the shell, or braze a nut onto the shell. Affix a bolt that you can adjust somewhat.

When you get done, you'll have a spark plug shell with a bolt that sticks out, maybe, 1- 1 1/2" or so. If you get on "Google" and select images, search camshaft, "positive stop" You'll see one down the page referring to Isky and Yamaha 650 bikes (I can't post links yet)

Now, probe the no1 plug hole to make sure you have clearance. Install the stop device, and with a wrench on the front balancer nut, CAREFULLY turn the engine 'til it stops--gently. Carefully mark an accurate point on the balancer at TDC. Now do the same in the CCW direction. What you will end up with is two marks, and if the original timing mark is correct, the "real" TDC will be EXACTLY halfway between those two temporary marks

Now, determine no1 on compression by one of two ways

A Bump engine with a remote switch, while holding your finger in no.1 You will have to be patient, and may have to "go round" more than once. When you start to feel compression, bump the engine up "somewhere" between 10BTC and TDC.

B. If you can remove the driver's side valve cover, bring up TDC with both no1 valves closed

Now, check the distributor. Since the dist. rotates CCW, the rotor should just be "approaching" the no1 tower, IE just CW of it. I always scribe a line on the distributor shell to match where no1 tower will be. IN FACT, you can turn on the key, and rotate the distributor, starting deliberately from "too far" CCW, and rotate the dist CW until the ignition makes a spark as it passes the reluctor, or opens the points.

If you do this correctly, the engine should fire as if you'd just parked it last night.

At that point, the engine should run. period.


Since you indicate that you "had the engine running" for a few seconds, it almost sounds--at this point--like the timing is severely retarded. Always hard to say from 'afar. This means the distributor needs to go further CW to advance the timing.

[wilks3]

440roadrunner is right on the money.
Another thing to check is vacuum leaks. Are all of the tapped holes in new manifold plugged? Mine weren't. #$&*!@!$&#!!!!!!!
Are all of the vacuum ports on carb plugged?
If all is correct, like 440RR said, it'll start up just like it should. First time.
Good Luck!!!

[rampage_82]

Well it sounds like to me that your timing is off, try advancing it some more, I would bet that your harmonic balancer has slipped...

[3404spdvaliant]

Advance timing till starter has a hard time turning the motor over then back it off a little.

[valiant64]

Make sure that when #1 piston is @ tdc that the distributor drive shafts' slot runs parallel with the block (front to back). It does sound like that its possible that the outer ring on the balancer could have slipped. Check it out.

[440roadrunner]

The only reason that the distributor gear is supposed to be installed this way is two reasons:

1 So the plug wires "lay" in a standard way around the block

2 So mechanics--back then--could depend on looking at the cap and expecting to find no1 wire in the expected spot.

You can drop the gear in anywhere, and put the distibutor in either way.

SO LONG AS THE NO1 wire ends up pointing at the rotor when no1 cylinder is ready to fire, the thing will run

The only engines where "it really matters" are the V6's and maybe a fw others where you have even/odd fire situations. In the case of V6s, the distributor towers are not evenly spaced--every other pair is closer together. This means that you either have to have no1 in the correct tower, or it can be "every other" tower around the circle.

On my first car, I'd had the distributor out a few times (57 chiv) and back then I didn't even KNOW there was a "certain" spot to install the distributor. One day I drove into a service station, and the guy checking the oil told me "it couldn't run" because the "distributor wasn't in right."

I drove it it. I drove it out.

[coronetcustom]

so it works after all.. problem was my new carburator/choke. i had it fully engaged and wetted plugs and drained battery. after charging battery i tried with 1/3 choke and it jumped alive. i did slight distributor adjustment when it was running. first run-in period went fine and looks like everything works like it should. will take it for drive tomorrow. thanks for all help.

[440roadrunner]

Well, that's how we learn, eh?

I fought a hot cam I'd installed in my old '64 426 for HOURS one afternoon, only to discover that the one plug that I'd dropped--and installed without looking--had the electrode bent closed.

[coupe32]

My engine was backfiring and would not start after the rebuild. Had several people over to troubleshoot the problem. After two days I finally found it myself. The coil wire going into the distributor was barely in. Pushed it in all the way and the engine started right up with no more problems. We all felt pretty stupid.

[66cornet]

...found a block ground wire wasn't hooked up...that was embarrassing