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-   -   HELP PLEASE! Engine Trouble (https://67-72chevytrucks.com/vboard/showthread.php?t=744098)

quentin hill 08-07-2017 09:02 AM

HELP PLEASE! Engine Trouble
 
I have a 72 C-10 350/330hp Holley 600cfm, HEI Dist, It fires but will not start!

I have checked the fuel pressure, Good!
I have checked for spark on the distributer, Good!
I had the carb rebuilt, Good!
I tried to replace the ignition module, still does the same thing
I checked the distributer cap for cracks or damage, all looks good
I checked the turn signals with the key in run position, Good!
I tried dumping some gas in the carb just to check, still does the same thing
I pulled the plugs out and cleaned them they were black as a struck match

The manifold has gas in it so its getting fuel, so I am assuming it's something to do with spark but when I checked it with a screw driver it had spark.

I don't know what to do, what am I missing? any help would be much appreciated!

70STOVEBOLT 08-07-2017 09:40 AM

Re: HELP PLEASE! Engine Trouble
 
If the engine is firing the module is good. Clean the plugs try it again. If you have spark at the wires then it is not a spark issue. Sounds like a flooding issue to me. If the center insulator and the electrodes on the plugs are black, it's been running too rich. Just because the carb was rebuilt does not mean there is not an issue with it. Has the engine been run at all after the carb was rebuilt?

quentin hill 08-07-2017 10:05 AM

Re: HELP PLEASE! Engine Trouble
 
"Has the engine been run at all after the carb was rebuilt?"

No sir it hasn't, I had the carb rebuilt because it di have a bad power valve and I thought that maybe the issues but it was only part of it.

BILT4ME 08-07-2017 10:39 AM

Re: HELP PLEASE! Engine Trouble
 
If it feels like it's popping back through the carburetor and will not start, it is very likely you have the distributor 180 degrees out. The engine has to turn over 2X for every ONE turn of the distributor.

Take the engine to the COMPRESSION stroke on cylinder #1, then pull the cap off the distributor and note the location of the rotor. It SHOULD be point directly at the #1 terminal on the distributor cap. (I make a mark on the distributor BODY to identify where the #1 plug wire lands on the body, since the cap is off when I am inserting the distributor.

Also, double check the wire connections from the cap to the plugs. Make sure they are in the correct order and start in the correct place on the cap.

We just got done doing this ourselves. I've done it many times, but I was teaching my son how to do it and what to check for symptoms-wise when that happens. Sure enough he had it 180 out.

He found TDC on #1 on the compression stroke by:
Remove spark plug #1
Insert a wet paper towel into the spark plug port
Disconnect the BATT wire from the distributor (if HEI) or remove the coil wire so you don't run spark.
crank over the engine with the starter JUST enough to have it blow out the paper towel. Since the engine will spin PAST TDC, you then know you must then rotate by hand for TWO FULL turns to bring it back to TDC on the compression stroke.
Pull the distributor cap and see where the rotor is pointing. If it's pointing at #6, then it is 180 out.

He pulled the distributor, rotated 180 and reinserted. He was SHOCKED when it immediately fired up!

Good Luck!

davepl 08-07-2017 11:12 AM

Re: HELP PLEASE! Engine Trouble
 
If the distributor has been out, then BILT4ME is likely right and that's the most likely cause.

If the dist has NOT been out, then I'd look at your carb, something likely when amiss when it was being rebuilt.

Nothing else changed since it last ran, if I understand correctly, so I'd narrow it down to what you touched.

factorystock 08-07-2017 11:51 AM

Re: HELP PLEASE! Engine Trouble
 
Check timing staticly. Line up rotor under #1 position on distributor cap, piston at TDC compression stroke, then look at pointer on timing tab near crankpulley. If it is way off, I would suspect a slipped timing chain. Common on higher mileage engines, but you didn't give us details on the mileage of your engine.

67 chevelle 08-07-2017 12:03 PM

Re: HELP PLEASE! Engine Trouble
 
If you have just one wire from the starter to the distributor , it will do this ,, most run a wire from the ing terminal on the fuseblock to the distributor .

bill3rail 08-07-2017 03:48 PM

Re: HELP PLEASE! Engine Trouble
 
Get back to basics, check everything carefully.
As was stated, Timing.

As was stated, A rebuilt carb may not be feeding fuel. Do you see fuel pumping into the carb throat when pushing pedal?

As was stated, check plugs to ensure they are not fouled out.

Bill

chiefcfd 08-07-2017 08:36 PM

Re: HELP PLEASE! Engine Trouble
 
Sounds exactly like my first start up. Had the same engine and carb. My distributor was 180 degrees off after checking and double checking before trying to start it. It is easy to get it off and not realize it. Hope you can get it going.

Captainfab 08-07-2017 11:28 PM

Re: HELP PLEASE! Engine Trouble
 
Is the float level in the fuel bowls of the carb set correctly?

cadillac_al 08-08-2017 06:43 AM

Re: HELP PLEASE! Engine Trouble
 
If the spark plugs got soaking wet they may never work again.

quentin hill 08-08-2017 07:16 AM

Re: HELP PLEASE! Engine Trouble
 
Thanks everyone, I rechecked everything but the one thing that I haven't tried that I have is what 67 chevelle stated below. This is exacly what I have going to the distributer, what is the "ing" terminal? I am no electrician, so if I run a new wire to the fuseblock I can eliminate the one to the starter?

If you have just one wire from the starter to the distributor , it will do this ,, most run a wire from the ing terminal on the fuseblock to the distributor .

68gmsee 08-08-2017 08:46 AM

Re: HELP PLEASE! Engine Trouble
 
Re. ing: He meant ignition. A straight 12vdc wire from firewall to HEI distributor. These older trucks had a resistive wire to drop the voltage down and HEI needs full 12vdc.

You've answered the question about the truck running "after" the carb rebuild, but did it ever run before the rebuild?

In other words, was the carb rebuild the only thing that happened before it quit running.

quentin hill 08-08-2017 10:03 AM

Re: HELP PLEASE! Engine Trouble
 
Thank you 68gmsee, Yes sir it ran fine before the rebuild, the motor has also been recently rebuilt it only has about 1000miles on it. Everything seems to point to that wire!

68gmsee 08-08-2017 02:36 PM

Re: HELP PLEASE! Engine Trouble
 
Quote:

Originally Posted by quentin hill (Post 8011429)
Thank you 68gmsee, Yes sir it ran fine before the rebuild, the motor has also been recently rebuilt it only has about 1000miles on it. Everything seems to point to that wire!

Just to make sure I read it right.

Are you are saying it ran fine for about 1000 miles then you had the carb rebuilt and right after the rebuild it stopped running. Correct?

If correct above, HEI does need full 12VDC but the wire may not be your problem. I'd check it anyway (a search will show you a lot of info on it).

As mentioned above, excessive flooding could be the problem.

HEI placement to make sure it's not 180 out. Remove the distributor cap, place the #1 piston at top of travel and in the compression stroke (both valves closed). HEI rotor should be pointing to #1 tower on the cap and harmonic balancer should be at "0" or TDC mark.

quentin hill 08-08-2017 02:43 PM

Re: HELP PLEASE! Engine Trouble
 
No sir it has about a 1000 miles on the motor and then just stopped, I thought it was a carb issues so I had it rebuilt and then it still wouldn't start not even with ether. The rotor to # 1 piston relation is correct

70STOVEBOLT 08-08-2017 03:28 PM

Re: HELP PLEASE! Engine Trouble
 
Does it turn over normally? No unusual noises when cranking?

quentin hill 08-08-2017 03:32 PM

Re: HELP PLEASE! Engine Trouble
 
Yes sir, turns over normally

70STOVEBOLT 08-08-2017 04:45 PM

Re: HELP PLEASE! Engine Trouble
 
Are you checking for spark at the plug end of the wire or the distributor cap end? Need to check it at the plug end, and it should be white-hot. If it is red/orange, then you are not getting sufficient spark.

davepl 08-08-2017 05:17 PM

Re: HELP PLEASE! Engine Trouble
 
Quote:

Originally Posted by quentin hill (Post 8011597)
No sir it has about a 1000 miles on the motor and then just stopped, I thought it was a carb issues so I had it rebuilt and then it still wouldn't start not even with ether. The rotor to # 1 piston relation is correct

Remember it could still be 180 degrees out unless you actually checked that you're on the compression stroke. It'll line up on the 0 mark twice each distributor rotation, and only one of those is correct.

Just to put it another way: you can have the timing mark at 0 on the balancer, rotor pointing at post #1, and STILL be 180F out. That's why you have to remove a plug, rotate the motor with your finger over (not in) the spark plug hole, and wait for compression to build behind your finger. Then advance the little bit left to line it up at 0, and THAT is top dead center.

68gmsee 08-08-2017 06:28 PM

Re: HELP PLEASE! Engine Trouble
 
[QUOTE=quentin hill;8011597]No sir it has about a 1000 miles on the motor and then just stopped, I thought it was a carb issues so I had it rebuilt and then it still wouldn't start not even with ether. The rotor to # 1 piston relation is correct[/QUOTE

On an engine with good compression, spark on all cylinders and timing is correct, just a small amount of gasoline poured into the throat of the carb should allow it to run for a short period. In your case, since it's been hard to diagnose, you may have to go back and check everything from the beginning.

Make sure you have good compression, spark on "all" cylinders (I use a timing light clamped on each wire so I can see if they're firing) and double check firing order.

garyd1961 08-08-2017 08:54 PM

Re: HELP PLEASE! Engine Trouble
 
Quote:

Originally Posted by cadillac_al (Post 8011327)
If the spark plugs got soaking wet they may never work again.

I've seen this before, more than once.

68gmsee 08-08-2017 09:10 PM

Re: HELP PLEASE! Engine Trouble
 
Quote:

Originally Posted by cadillac_al (Post 8011327)
If the spark plugs got soaking wet they may never work again.

Quote:

Originally Posted by garyd1961 (Post 8011813)
I've seen this before, more than once.

Agree. I've had that happen many times also.

saxart 08-08-2017 09:54 PM

Re: HELP PLEASE! Engine Trouble
 
Quote:

Originally Posted by 68gmsee (Post 8011828)
Agree. I've had that happen many times also.

I'm confused... How does gasoline soaking spark plugs "ruin" them?

cadillac_al 08-09-2017 06:32 AM

Re: HELP PLEASE! Engine Trouble
 
Quote:

Originally Posted by saxart (Post 8011876)
I'm confused... How does gasoline soaking spark plugs "ruin" them?

I don't quite know the how but I've seen it happen. When my 76 Seville had fuel injection problems it would drown the plugs with gas and they would not fire. One time I had a brand new set of plugs and drowned them in less than 2 minutes. I didn't want to throw them away so I put them in my good running Cutlass. The Cutlass would not start with the wet plugs. I put the old plugs back in the Cutlass, took it for a ride and got it nice and hot. Then I swapped out the plugs and put the wet ones back in the Cutlass. It barely started and spit and sputtered and misfired for a couple miles before it cleared out. I was able to save that new set of plugs but it was a hassle. If the plugs had any miles on them at all, it wouldn't be worth it to go through the hassle of swapping plugs in a hot engine.


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