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Just put an HEI module on a probe gt that was having a nasty ignition miss and it didn't really seem to help a whole lot.
Anything else we should look for? I got the timing set to 10 degrees with a light, and I'm pretty sure we got the HEI on properly. We did NOT do an external coil. Just the HEI.
Should the HEI get warm while in operation? This one stays quite cold.
We got a very good ground on it, I soldered all the connectors except the ones that go to the sensor plugs. For those, we used the splicing clip things.
It has new plug wires.
It has relatively new spark plugs (I wanted to look at them but we ran out of time)
Distributor cap and rotor are in decent shape.
Any ideas? She is still missing.

Edit: ECU codes... IAC solenoid, vris 1&2 (don't remember the #s, but that's what they mean according to my friend who owns the car)
-Eric

Did you disable the stock ignitor module?

http://www.mx-3.com/phpbb2/viewtopic.php?t=53706

For some reason, I thought you only had to do that if you were doing the coil as well. I took the distributor off so that we could do it, but he insisted that we didn't need to so we just left it alone.
All we have to do is cut the top (orange ecu trigger) wire?
-Eric

rccardude04 wrote:All we have to do is cut the top (orange ecu trigger) wire?

You can start by cutting the orange wire - However it is highly recommended that you also cut the Black/Green wire to completely disable the internal ignitor module.

Also reset the computer after you are done.

the HEI should only get hot if it isnt grounded properly, so it being cool is a good thing

Just making sure 100%... You disable the ignitor even if you aren't using the external coil?
What # wire is the black/green wire? (looks like #2, but I want to make sure... colors are a lil different on the probe )
-Eric

yep

Cool. Thanks.
Any other ideas on why it might be missing? Just general stuff to check I guess. The cap/rotor didn't look perfect but it didn't seem bad enough to cause the miss.
-Eric

Do a compression test. And put your timing light on each plug wire individually while the engine is running.. if the light flashes nice and even on all 6 wires.. its likely a valve seating issue.. the compression test will also reveal a valve seating issue. If the timing light flashes inconsistently on one or more cylinders.. then you can be assured that the issue is indeed in the ignition system somewhere. Best of luck

Tunes67

Genius! Never thought of using the timing light to check the spark. LOL.
I'll do that for sure.
As far as compression goes, I don't have any way to check it and no local shop will do it without charging. I'm about 99% sure it's an ignition miss though.
He says it's better with the HEI module, but I'm going to go visit him to disable the igniter and what not. Otherwise, he has no way to get the car home other than a tow truck. And that's no fun
Any other nifty tips?
-Eric

Still missing...
I put the timing light on each plug wire and it misses about the same on each one. It's not just one wire/cylinder that's got the problem.
I did disable the internal igniter by cutting the two wires, and it actually became a little more difficult to start. The HEI module got to about 90 degrees max (ambient module temperature without being run for a while was around 80). So it's grounded, it's firing sort of.

When you step on the gas suddenly, the thing tries to die. If you stay on the gas, it will stop running completely.
Plug wire resistances are 1500ohms on the fronts, 3000-3400 on the rears, and the plugs look decent.
Any ideas?
-Eric

Did you reset the ECU?

rccardude04 wrote:When you step on the gas suddenly, the thing tries to die. If you stay on the gas, it will stop running completely.

That sounds like a vaccum leak....


You also mentioned an IAC code in your edit - have you fixed that?

The IAC code, according to everybody that he has talked to, is supposed to be not a big deal and shouldn't cause an ignition miss.
Vacuum leak doesn't sound like fun lol.
Would a vacuum leak cause an ignition miss though? Seems like it'd just make it stumble. This is definitely losing spark (tach drops as well as the timing light not flashing consistently)
-Eric