# 70 GTO - Ignition Problem??



## 1970GOAT (Jul 10, 2011)

Hello all!

I recently had the opportunity of a lifetime and bought a 1970 GTO (real 242 car). I would consider myself fairly car-savvy, but muscle like this is not exactly my forte as it's my first classic. 

Anyway, the problem started when I went to replace the battery in the car. Keep in mind it was running up to this point. Someone, somewhere along the line decided it would be a good idea to make the positive cable to the battery black and the ground wire red and when I put the battery in, I reversed the current through the system. I know, it was a REAL bonehead mistake. It wouldn't run anymore, and after doing tests with a multimeter I replaced several components including the alternator, voltage regulator, and coil (it has an HEI ignition system). After doing so and it still not running, I realized it wasn't getting fuel and replaced the fuel pump and filter - fuel problem fixed. However, it still wouldn't run so I replaced the HEI distributor cap, rotor, and coil (I believe the old coil shorted out due to a lack of a good ground connection - I found out the cap had a stripped out hole where the coil ground is). Finally it ran again (a little rich now, I took apart the carb during the diagnosing process) but I didn't drive it due to a leaky brake line. Tonight I replaced the brake line and went to start the car and it started up, ran really rough, and had almost no throttle response. I could smell and see fuel coming from the exhaust pipes so I shut it off and tested for a spark at the wires - orange. I had the same problem before I replaced the distributor cap/rotor/coil and didn't check it immediately after because it ran and I therefore assumed it was fixed. 

Sorry for the long-winded story, but I'm getting to the point where I don't know what it could be. I know there's a possibility the ignition wires, ignition module, and pickup coil could be bad (as I haven't replaced them) but everything else is new. However from looking online those don't appear to have the same symptoms as I'm having. So my question is,

DOES ANYONE KNOW WHAT'S WRONG WITH MY GOAT? :confused

Any and all help is appreciated! Thanks for your time! 

-Bobby


----------



## 1970GOAT (Jul 10, 2011)

Any ideas? Anyone?


----------



## Eric Animal (Oct 28, 2007)

When you say fuel coming from the exhaust, do you mean LIQUID GAS, or black "rich' smoke?


----------



## 1970GOAT (Jul 10, 2011)

Thanks for the response! I'm not sure unfortunately as my cousin was the one who was behind the car while I sat inside... I know it was smoking though. It ran like it wasn't firing on all cylinders and the engine shook quite a bit.

My next step is going to be pulling all of the spark plugs to see what I can find out, and before I do that I'll try and start it again and find out exactly what's coming out of the tailpipes.


----------



## pontiac (Mar 6, 2011)

reversing the battery leads will fry about everything, including the HEI module, coil pickup and the coil itself. if you replaced all those correctly, did you buy the BOP HEI coil, not the Chevy one and a correct module as well with the heat sink grease underneath? that will give you an inferior spark, orange? Also, you need to confirm that the HEI is getting a full 12 volts all the time. You may have killed the ignition and engine harness wiring by changing polarity.


----------



## 1970GOAT (Jul 10, 2011)

Not sure what BOP means, but when buying HEI parts I have to tell Kragen (or whomever) that I need parts for a '74 Pontiac GTO because in 1970 they didn't use HEI ignition so the parts don't show up in their system. And with the key in the "RUN" position I'm getting 12.2V (roughly) to the coil so I *believe* everything is o.k. within the harness. It is putting out a weak (orange) spark though, so you believe it could be the ignition module? I have yet to replace it so I will check that next.


----------



## 1970GOAT (Jul 10, 2011)

Ok, I pulled the spark plugs and they were all fouled (black soot). I cleaned them with gasoline and a rag and then sprayed them dry with a shop vac. When I reinstalled them, the car started up and ran for a little bit (maybe 30 seconds to a minute) but started running rough and then died. There was white smoke coming out of the exhaust, but it didn't appear to be white-blue (oil) and it smelled strongly of gasoline. I also pulled one of the spark plugs and it was wet with gas. 

Any thoughts?


----------



## freethinker (Nov 14, 2009)

1970GOAT said:


> Ok, I pulled the spark plugs and they were all fouled (black soot). I cleaned them with gasoline and a rag and then sprayed them dry with a shop vac. When I reinstalled them, the car started up and ran for a little bit (maybe 30 seconds to a minute) but started running rough and then died. There was white smoke coming out of the exhaust, but it didn't appear to be white-blue (oil) and it smelled strongly of gasoline. I also pulled one of the spark plugs and it was wet with gas.
> 
> Any thoughts?



sounds like the carb is flooding over. needle and seat stuck?


----------



## dimitri (Feb 13, 2009)

A general rule of thumb with HEI ignitions. Always replace the coil, the module, and the magnetic pickup as a set. 

Put a new set of AC Delco spark plugs gapped to .040". I never use anything other than AC Delco plugs. I replace my plugs every 10,000 miles or every summer.

Check the resistance of every spark plug wire and replace them if they are bad. Make sure the wires are not metal core!!!

Leave the carb alone. I think you are not putting proper flame to the fuel.


----------



## 1970GOAT (Jul 10, 2011)

I pulled the whole carb apart a while ago, and I though maybe I had accidentally adjusted the mixture and that was why it was running rich. The needle valve appears to be moving freely on both the primary and secondaries though so I don't *think* that's the problem. I might try adjusting the fuel mixture though.

@dimitri: I didn't know the module and pickup coil were supposed to be replaced as well! I was going to check those next, but at this point I'm considering getting rid of the HEI system all together. I've talked to a few people who say that this HEI system is not necessary and I could switch over to a regular MSD system that would be more reliable and just as good for my application. I don't think it makes sense to dump another $200+ into this frankenstein HEI system when I can buy a whole new MSD system for around 450... right?

EDIT: Also, I put NGK Platinum plugs in it because that's what was in it when I pulled out the old plugs (which had been running fine before all this mess) and I gapped them to .035" because that's what the FSM said. Should I gap to .040"?

THANKS AGAIN FOR ALL THE HELP GUYS!


----------



## freethinker (Nov 14, 2009)

1970GOAT said:


> I pulled the whole carb apart a while ago, and I though maybe I had accidentally adjusted the mixture and that was why it was running rich. The needle valve appears to be moving freely on both the primary and secondaries though so I don't *think* that's the problem. I might try adjusting the fuel mixture though.
> 
> @dimitri: I didn't know the module and pickup coil were supposed to be replaced as well! I was going to check those next, but at this point I'm considering getting rid of the HEI system all together. I've talked to a few people who say that this HEI system is not necessary and I could switch over to a regular MSD system that would be more reliable and just as good for my application. I don't think it makes sense to dump another $200+ into this frankenstein HEI system when I can buy a whole new MSD system for around 450... right?
> 
> ...


the brand of spark plug doesnt make any difference/ yes gap to 40 with hei but that is not your pronlem.
the hei system is a great system. i would say just as good as the msd system. yes the module should have been the first thing you changed.

i still suspect flooding because of this "There was white smoke coming out of the exhaust, but it didn't appear to be white-blue (oil) and it smelled strongly of gasoline. I also pulled one of the spark plugs and it was wet with gas. "
what kind of carb is it?


----------



## 1970GOAT (Jul 10, 2011)

The reason I would rather go to a standard MSD system instead of an HEI ignition is because there is less to go wrong with it, and I'm not sure what brand HEI distributor is on there. So If I'm going to dump money into it, I would rather put in something name-brand that I know is going to be good.

And I agree, I still think the fuel system might be a problem. It's a Holley double-pumper.


----------



## OrbitOrange (Jul 5, 2010)

The factory GM HEI is good stuff. I wouldnt go throwning more parts and money at this thing just to have a "name brand" ignition system. 

BTW, welcome to the site. Sounds like you jumped into this thing head first!


----------



## Instg8ter (Sep 28, 2010)

BOP = Buick, Olds, Pontiac

If General Motors HEI is not a "Name Brand" i don't know what is....
millions of cars have used this ignition, it puts out 40,000 volts is compact and self contained and the parts are cheap and available at any corner auto parts store. Ever try getting service from MSD....may as well buy another 400.00 box. :willy:


----------



## Rukee (Feb 8, 2007)

Points<HEI<MSD


----------

