GM HEI Distributor cap/rotor swap... RESULT = spark + gas = no start????

[fiveoh 86lx]

So I have the GM HEI set up on a ford 302....
I started out having a decent running vehicle (was skipping, I think the timing was just off but I checked the cap and it seems it needed changing, also wouldn't rev over 4k under load). I ended up buying a new cap and new rotor, and swapped them over just fine.

Tried starting and had a quick fire and started but stalled right out.
Checked the spark, getting spark, and getting fuel.

So I ended up swapping the new cap and rotor back to the old cap and rotor; turned over, with no start. Gas and spark but no ignition.

Wires and plugs were new 5 months ago right before I put it in storage.... All the wires are in the correct order, rotor is on correct.
I don't think I changed the timing at all just changing the cap and rotor......

Both the C- side and the B+ side are getting 12 volts, I think thats normal?
Never had to deal with this setup.

STUMPED....
Surprised my father can't even figure this one out.
Help would be greatly appreciated!

[Matt51F1]

Where are testing that you get the spark? From the coil or out at the plugs?

The first thing that would come to my mind is: are the distributor/leads at the correct position? ie: trying to fire #5 when timing is on #1

If you have spark and fuel then the conclusion to me is that it is not firing when the cylinder requires it.

Turn the motor manually so that it is at TDC (or wherever you have the degrees set forward 8/10/12 degrees, etc) for #1 and that the rotor button (ah crap... does that dizzy have a rotor button??) is pointing at the correct lead for that cylinder.

I've done this myself where the leads have been one plughole out. Easy to do

[fiveoh 86lx]

Using a timing gun just seeing if the light was working, couldn't tell if they were just getting maybe a real weak spark?

I'm not sure what you mean by rotor button, first time i've done anything with a distributor besides change a cap and rotor, sorry for my lack of knowledge.

Just wierd to think the timing would have changed when all I did was change the cap/rotor... Will probably have to play with the timing tomorrow night...

[Floyd]

Assuming its HiPo by the valve covers. Did U use a standard 302 firing order? Cause they are different.

[PaceFever79]

I'm no GM expert, but I have some experience.

Might be the coil module pack (on top of the distributor cap). It uses a special grease to
insulate the module. If it is grounded out or bad it won't properly charge the coil. If you
used your old module, I would try replacing it with the proper grease.

Here is a good detailed tech article on HEI

http://www.chevyhiperformance.com/te...les/index.html

[85GT-79FJ40]

Are you absolutely sure the distributor was installed correctly? You can have all the plug wires on correctly but if the distributor was installed out of time it's not going to run. It might kick over quickly but it won't run. I would turn the engine to TDC and pull the cap off and see where the rotor is pointing.

[83GLCoupe]

Make sure that the 3 wire plug is seated correctly in the cap. On the 2 connections on the end, you only need B+ hooked up. The other connector is for tach output. When you move the coil over to the new cap, make sure all the wires sit firmly in their socket and don't forget to include the grounding piece the goes into the center of the 3 connectors and sits under the coil.

[cb84capri]

you say it back fired, perhaps it took out the power valve and is now dumping excessive fuel into the engine. i dunno, i'm not a holley expert.

if that is the case, you might be able to get it started by holding the accelerator to the floor while cranking.

cale

[JACook]

Need to go back to square one here, and cover the basics before diving any deeper.

Find TDC, compression stroke by pulling the #1 spark plug, bump the starter till air comes
out the hole, then use a screwdriver to feel for TDC while turning the engine by hand. Do
not trust the timing marks on the damper.

Then check that the distributor is pointing at the #1 tower, and that it's wired with the correct
firing order, in a CCW rotation. Correct as needed. That should get it at least close enough
to fire, unless it's failing.

If the TDC mark on the crank damper does not match TDC observed with your screwdriver,
get a new damper. Ford Racing sells a nice factory one for the same price you'll pay for a
McParts store replacement.

I'm trying hard to resist telling you to get a different distributor while you're at it, but given
the reliability record of those Summit HEIs, I figure that may take care of itself anyway.

[mudgepondexpress]

It is wired as a non-HO as posted previously (1,5,4,2,6,3,7,8 ). If the valve covers are correct for the car then is should be 1,3,7,2,6,5,4,8. Next, bring it up on TDC (thumb over the #1 plug, when it blows off, hand turn the engine until TDC) and see where the rotor points. Could the old cap have been installed wrong then the wires adjusted to make it work?

Good luck.

[PaceFever79]

OP said it was running okay but had a slight miss and wouldn't rev over 4000 rpm before
replacing cap and rotor, so it would seem the distributor is installed properly since it has
not been removed. The firing order could be wrong, it's easy to mix up a wire when you
swap them over if not done one at a time. If that's all good, I think it's something in the
coil module or leads which had to be swapped over to the new cap.

I do agree it is hard not to just say replace it all with stock distributor / ignition!

I see no need for HEI other than that is what you have.

[grtskydog]

Is that EGR port covered up? Looks like a non-egr spacer on a EGR intake.

[JACook]

^^^ Yep. Good eye. That looks to be a Performer 302 EGR intake.

I don't think the spacer mismatch is necessarily causing a vacuum leak, but if the exhaust
crossover passage is active, it's probably leaking exhaust there.

There's a few things in that photo that make me go "hmm..."

The more I think about it, I believe I would pull that distributor and check the gear.

[brianj]

pull the distributor an put a stock ford unit in.This conversion just adds an unneeded degree of uncertainty to your car for very little benefit. If for no other reason, you would be able to order parts for your model and year of car, and get help on a ford forum for a ford car, and not be trying to figure out g.m. parts!

[JACook]

I agree in principle, but at this point it may not be as easy as just pulling one out and putting
the other in. So I have been resisting just condemning the existing HEI out of hand. I would
rather not just say swap the HEI for a proper Duraspark system, without proving that the HEI
is failing first.

Now if it does turn out that the HEI is at fault, then I would absolutely not advise the OP replace
it with another HEI, or even try to repair it. But we don't know what the PO did to the wiring
when he installed the HEI either...

[brianj]

Very true- I was just thinking that if he went back to original, at least he could go back to original wiring diagrams, et ct. instead of trying to figure out someone Else's mess. It is never much fun.

[PaceFever79]

If we determine the HEI module or coil is faulty, I would pitch it in the trash and buy a
stock Distro with a new Motorcraft or MSD. Just on principle! Sorry man but that thing
just looks goofy stuck on top of a small block Ford!

Let's hope that it's bad.....

[fiveoh 86lx]

My wallet it glad it isn't faulty!
Everyone's going to face palm after hearing this but....
Apparently I hit the choke....
Suffocated the engine, pulled my dipstick and smelled like gastank!
Got it all re-arranged and is now running better than before!
But found more problems... New Thread time...

[JACook]

Wow. Well, glad it's going again, however you got there.

[brianj]

If it is any consolation, I watched a man who was a very good Porsche tech. rip the headliner and most of the interior out of a two year old 911 chasing a break in the interior light harness- only to remember he never checked voltage at the fuse panel. The fuse was blown.

[fiveoh 86lx]

If it is any consolation, I watched a man who was a very good Porsche tech. rip the headliner and most of the interior out of a two year old 911 chasing a break in the interior light harness- only to remember he never checked voltage at the fuse panel. The fuse was blown.

I feel bad for him!
But my problem is just plain ignorance and thinking too hard