HEI rebuild, no start. Help.

[dbozman]

'74 K5 with 454. Truck was running prior to beginning work. Pulled all the plug wires. Pulled the cap and noted the position of the rotor. Scribed a mark. Unloosened hold down and pulled distro up and out, noted the CCW movement of rotor and scribed that.

Rebuilt distro with Summit HEI kit. Nasty inside. Sprayed some electrical cleaner inside and got all the gunk out. Replaced the weights and springs. All new module. New cap, rotor and coil.

Reinstalled the distro using previous scribe marks (motor was not bumped over). Dropped right in. Plugged the three-wire connection from module to cap (red to B+). Ran new plug wires in proper order.

Truck will turn over but won't fire.

Now the tricky bit. Normally you'd have a tach line to out plugs on cap and a power line. I have a tach line and a line from a PO-installed kill switch. I reattached it just like it had been installed and worked previously. No start.

I'm not an expert at this. Can anyone give me some guidance? Where to begin? How to test to see if I've got juice at the distro?

Any help appreciated.

 

[dyeager535]

As I recall with carbed apps, should have a single wire (pink w/white connector?) for the coil. That wire should have 12V with the key in "run".

 

[dbozman]

Anyone else answer some of the specific questions in the first thread. Really need some help here.
d

 

[dbozman]

No one has HEI experience?

 

[BigBen]

Like Dorian said:

Check for 12v from the power wire at the distributor with the ignition in run. Use a multimeter or a test light. Once you have that checked, you'll need to make sure you've got spark at the plugs.

(I believe the power wire is pink on HEI original trucks, like Dorian said. On points trucks, which your '74 is, I'm not sure. I think it was yellow. My '74 was swapped when I got it, So I'm not 100% sure on what color it was.)

Two questions:

1) Did you remove the resistor wire when you swapped to HEI? (Search for Resistor wire if not. It has been covered here a LOT) If the resistor wire is still in there, you will have nothing but problems.

2) Did you put dielectric grease under the new ignition module when you put it in? That is NECESSARY for cooling the module and you could have fried it if you didn't.

Check these things out and report back... then we can help more.

-Ben

PS> There is plenty of HEI and truck experience here. Ask clear questions with a good attitidue and you'll be amazed how helpful everyone is.

 

[mrdrinksalil]

x2 what big ben said.

Check your power to the dizzy, then the power to the plugs.

 

[dbozman]

Ben: I thought my questions were very clear. Let me rephrase:

The HEI was already in the truck when I bought it. It was running. The PO had installed some sort of kill switch. The power feed off of the kill switch is what was running to the battery line on the HEI before disassembly. It's currently lined just the way it was when I disassembled it.

Yes, I used dialectric grease under the new module.

I basically just pulled the dizzy in the manner I outlined in the first post. Took it apart and installed new parts in kit. Reinstalled and no start.

It's got a three-wire clip that conntects the module to the cap. Is it possible to reverse install that clip?

I do have a multimeter, but I'm not much good at tracking electrical issues. Can you describe specifically how to test for 12v at the power junction of the cap?

Is it likely, based on how I pulled and reinstalled the distributor, that I've got it way out from its base timing, which is reason for the no-start?

Thanks.
d

 

[BigBen]

I didn't really understand the first time through.... but just because I didn't get it, doesn't reallly mean much!! My head is usually much in the AM.

I should have asked this first: Is this an 'in-cap' self contained HEI? I'll assume that it is.

Dielectric grease - check!

Use your multimeter to check for voltage at the distributor:
Set it to DC volts. If it has a range, do the first one that is bigger than 12v.

Pull the white-ish plug (power) off the HEI cap. Make sure it can't touch anything metal under the hood when it is disconnected. Turn the ignition switch to 'on', but do not start the truck.

Put the red lead (+) of the multimeter in the connector and touch the black lead (-) to anything grounded on the truck (almost anything metal). You should read about 12v on the meter. If you read 0, you're not getting power. If you read something like 9.5v, your resistor wire is likely still there.

You can use a test light for this, but probably won't tell you the difference between 9 and 12... but it will tell you if there is juice there at all.

If you have 12v there, the next thing I would do is check for spark when you're trying to fire the engine.

If spark: Then I'd start digging into timing.
(Stupid thought: will it start on starting fluid?... gas?)
If no spark: Problem is likely inside the distributor... and will take more digging.

If you DON'T have any voltage, I'd try bypassing that kill switch and see if it will work with 12v to the dizzy. You could even run a cheater line to it off the battery for trouble-shooting.


As far as the the three-wire plug from the module, I think you'd have to work pretty hard to put it in backards... but I won't say it is impossible.



After re-reading, your process sounds pretty thorough for replacing the distributor. Likely there is just some strange electrical gremlin fighting you here......

 

[dbozman]

Uh, well, I guess I should've checked the simple **** before panicking. Traced the wires for the kill switch back through the firewall and found ... a bad fuse.

Replaced. Truck starts.

Dumbass award goes to me today. Thank you.
d

 

[BigBen]

If you want that dumbass award... I might need to ship it to you!!!!!
(I've earned it myself plenty of times)



Just glad to hear you got it all sorted out and running again!



(Doesn't it seem like the simple problems are the hardest to find sometimes?)