slow305

iTrader: (2)

My Formula ('90 with a 305 TPI) died on the way to work Monday. I just pressed the gas pedal to merge into traffic, and it just plain quit. Towed it back home later that night and just got around to trying to diagnose things today.

After an initial search here, I decided it might be the ignition control module. $27 later from Auto Zone, and the car still doesn't start.

I can hear the fuel pump. When I changed the fuel filter (thinking THAT might be an issue), I just turned the key so the pump would prime (with no filter) and gas came out of the fuel line.

The car turns over like it wants to start. All the electronics work. The oil pressure gauge rises as I try to start. I have a Factory Service Manual but can't seem to find a troubleshooting guide.

So anybody else have ideas?

dankhound

Your vats(vehicle anti theft) may have malfuntioned. Do you have spark? Do your injectors get a signal from the computer? Just because your pump works doesnt mean your injectors are giving you fuel. You should be able to buy testers for both fairly cheap.

slow305

iTrader: (2)

After some fiddling and a few suggestions, tonight I went out and re-installed the old coil, and the car started right up! ?? I put the new coil back on and ensured all the connections were secure, and the car didn't re-fire. So anybody have an idea why a 2-3-month old MSD Blaster Coil would fail??

Nixon1

It's been known to happen. Sudden, unexplained coil failure...I know a couple guys it's happened to. I wouldn't know what causes it...maybe it just overloads itself. The factory location also exposes the coil to a large amount of heat from the exhaust manifolds, which might've contributed.

MSD is VERY good about warrantying their stuff. Give them a call, they'll probably want you to send the coil back to them. They'll check it out and send you a replacement.

IROCThe5.7L

I put a MSD blaster coil in my daily driver. It lasted a week and died on me. Had to push the car home

slow305

iTrader: (2)

I knew there was a reason I kept the old coil. Seriously, of all the things that went through my head, "coil" was not something I suspected as being a source of my problem. After all, it's the newest thing under the hood (after the spark plugs).

Nixon1

Never had a problem with my Blaster TFI.....
But then again, mine is mounted on the fender, where it's not exposed to all that heat. Maybe they'll last longer if you, can relocate the bracketry.

Kuejo

I'm having a problem with stalling that I haven't been able to isolate yet - changed distrib, pick-up coil, ignition module, fuel pump - still get stalling while driving.

Gonna look at the coil, but getting pretty frustrated.

Jonathan

Nixon1

Is it at cruise or deceleration? Try checking out your IAC valve/motor. If it's sticky or slow it'll cause stalling.

As far as a coil failing intermittently....it may be POSSIBLE, but I've never heard of that happening.

Kuejo

Under acceleration, deceleration, and while loafing along. The most frustrating is while under power - it's like someone pulled the coil wire - there's no hesitation, warning, bucking, spitting - nothing. It just stops running. If I'm coasting along, I may not even be instantly aware (haven't got a real loud exhaust sytem in this car - which, BTW, is a 350 TPI - 1988)

It's also very interesting to me that the car seems to coast so well while still in gear - at least as well as if it were in neutral (automatic tranny). I wouldn't have thought that it would coast so well - that the tranny turning would turn the engine as well, or at least that it would slow down much more quickly. But I'm no tranny expert, by any stroke of the imagination.

I'll pull over, have to give it a minute or two, and then it will start again.

The SES light will come on while it's stalling, but goes off as soon as I get the car restarted - gonna go out this afternoon and see if I can coax it to stall and then throw the coder on it to see if I can pull some codes.

I have a hard time believing it's the coil as well, but I went ahead and picked one up ($24 isn't TOO bad, I guess...) anyway - at least that way I'll know that's not the problem.

Jonathan

Nixon1

You don't need to get it to happen to again to pull the code. They're stored in memory for something like 50 starts. But to be sure which code it is it's always a good idea to reset the computer and let it happen again before you pull it. That's assuming you pull the codes before the restart and find more than one of course.

Definitely sounds like the ICM overheating to me though... No sensors will generally result in abrupt stalls at any throttle position and engine load condition.
Did you apply a lot of dielectric grease on the base?

Let us know how the new coil works out also, if it still acts up or not.

Kuejo

I have a hard time imagining (but recognize that it's not impossible) to believe that it's the ignition module since it is brand new, and I was generous with the Arctic Paste (heat sink paste that came with it - I screw with computers too - I'm very familiar with this stuff).

You bring up a good point about clearing the codes - I'm going to do that right now, and then run the car again and see what comes up.

The code 51 (MemCal error) has me thinking that this MAY be an ECM issue, as I have tried both the Hypertech and stock GM chips with the same problem. Not that I want to spend more than I have to, but for $75 maybe I should just replace the ECM too - will clear the codes, and run the car for a bit and see what happens before I do that, but aside from mowing the grass I've got the rest of today slated to this project!

Jonathan

Kuejo

And now I'm only getting code 51. That's been an ongoing problem, so will try to swap the chip and see what happens (in the theme of "one fix at a time"!)

Just out of curiosity - can someone explain the difference between a "soft" code and a "hard" code? I'm not sure I'm using those terms correctly, but the way I understand it a "soft" code refers to a code that does not trigger the SES light, but does come up if the ALDL is checked.

Car seems to be running well overall, but haven't taken it any distance yet...

Jonathan

Nixon1

Havent heard of them referred to in those terms...but then I've never heard someone ask/talk about those types period. But yeah, a 'soft' code I'm sure would be just what you said. Hard code, it'd throw a light and go in memory. I forget all the terminology associated with the Gm cars, but the Ford terminology is a KOEO code(Key On Engine Off), KOER (Key On Engine Running), and then there's the intermittent code that gets thrown and then disappears, which is very common.