Motor problems

[harrdawg54]

I have been working on restoring my truck for a year and a half and have had the replacement motor (Rebuilt) for 2 years. I finished the body work and electrical and tried to start the motor for the first time, nothing. It would crank but not fire, so I tested everything and found problems with the HEI. I bought a Skip White HEI and installed it today and was able to start it, but I couldn't keep it running. It would backfire through the carb which made me think that it was 180 out so I swapped it and couldn't get it started. Swapped it back and got the same issues. This is my first resto and am very green when it comes to just about everything about these trucks. I would like to get it running smooth soon so any help would be great. Thanks.

[aggieguy713]

Might be a vaccum leak, not sure from where. Just my .02

[LockDoc]

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Have you used a timing light on it yet?

It sounds to me like you might have a couple of plug wires in the wrong place. I would go over the installation again.

LockDoc

[cdowns]

double and triple check the plug wires r in the right order on the cap/// hope you didnt use the original truck wiring for the HEI

[Muleman100]

Are you sure its not the carb? Backfire and not running could be the power pump in the carb.

[Sinister]

I just went through this. If your sure the distributor and plug wires are installed correctly, try advancing the timing. Turn the distributor body counter clockwise a little and lock it down. Then see if you can keep it running and reset the timing with a light. My carb was new, also had to floor it a little to get some junk out of the idle circuit.

[harrdawg54]

All new wiring for the new HEI, new 1406 carb, new plugs and wires. I thought I went through and double checked the order of the plug wires but I could have missed something. I am getting a timing light from a friend after Christmas so I will try it then. It did start easier when I advanced the timing. It will be nice to get it running, it's been a long time since I drove my truck.

[BAGNDRAGIT]

defiantly sounds like a timing issue.

[truckdude239]

timing is off

[mr48chev]

I'd agree that the timing is probably off.

For some reason if we get the wires crossed on one of these engines, It's on #5 & 7 as they are right beside each other in the firing order and in the block.

[vectorit]

I too think it's mostly timing, but a serious vacuum leak could be an issue as well. Being that none of us can see n' hear what is going on, all we can do is speculate on the cause.

As for me, I'd do the following. Mainly because it's a new rebuild, and it has been sitting for a while. Who know's what may be incorrect.

1. Pull all spark plugs, and the driver side valve cover.
Doing this is not required, but being that you are green at this...

2. Turn the motor over to TDC compression stroke. (pulling all plugs helps in turning the motor over by hand, and so that you can hear the woosh of air from the number one hole. This will be the compression stroke).
The rocker arms on the number 1 cylinder should be slacked, meaning that both intake and exhaust valve are closed. If they are not slacked, but tight enough to open a valve double check your rotation. If you are sure you are on TDC compression, then the rocker arms could be out of adjustment. Common thing on newly rebuilt motors, since they can be roughly adjusted on the stand.

3. Pop the dist. cap, and see what direction the rotor is pointing. Does it point to the number one plug wire terminal?
3a. NO? pull distributor, and clock the rotor so that it does.
3b. YES? put your plugs back in, reinstall valve cover and dist. cap.

4. Pull all plug wires, and verify they are plugged to the correct firing order.

5. Have you verified the carb base gasket is correct?
If not, you will have a massive leak.

6. Have you verified that you have the correct carb for the manifold you are using?
If you are using the stock spread bore design, and then using a square bore type carb such as the Edlebrock. Then there could be an issue there as well.

7. Did you connect or plug off your power booster vacuum fitting at the rear base of the carb?
Often forgotten, since you can either use that connection or the one on the intake manifold for the power booster vacuum.

Here are some video's that might help you out:

YouTube- How to Install Distributor Video-Engine...

YouTube- Engine Ignition: Wiring Distributor...

Hope that helps a little for you.

[harrdawg54]

I think I found 2 vacuum leaks, one under the carb spacer and another from the manifold to the booster (major leak). Going to work on it after Christmas. THANK YOU for all the replies, I will be updating this with either more questions if it doesn't work or a vid if it does.

[mstrav1973]

I wish I could help but your a little far north for me in snow season ( I'm in Boise). Start with wires, cap off all un used vac lines and disconect your vac advance at the carb and cap for now. Make sure there are no leaks around the carb base gasket. Distributer should be snug but not tight yet for adjustment. I just started mine a month ago and she fired right. The main thing is to double and triple check before you fire it up. Is the power running throught the harness or a remote start set-up?

Matt

[unclewatts]

Hey Vectorit, those are some great instructional videos. It never ceases to amaze me about all the stuff you can get from You Tube.