Mechanics

CHEVY 97 - CRANKS, WON'T START - BAD IGN C

1997 Chevrolet Astro

Engine problem
1997 Chevy Astro 6 cyl Two Wheel Drive Automatic 127000 miles

Me too - leaky coil

I just finished up a couple months of fooling around with a 97 Astro that would quit without warning, fire back up sometimes, sometimes not. It would run all day one day, then not start the next. I make service calls, putting on 100-150 miles a day. I don't enjoy getting stuck far from home, or spending a lot of unnecessary money.

Well, now I can say, with only a little trepidation, that it is finally fixed. I had the same problem that Chubber22 posted under 1996 Chevy Astro won't start: a bad ignition coil. Here's my story. Hope it helps someone.

I bought the van used about two and a half years, and 68K ago. The fuel pump was noisy all along, with a high pitched whine which would get louder on hot days, but it worked nonetheless. One day back in September we had a heat wave up into the 90s. The fuel pump got louder than ever. Then the van started stalling pulling out from a stop. But it would restart right away. Then it also started stalling on right hand turns, but again would restart. My tank was full. This happened all on one day. I suspected the fuel pump, and took it to a local garage the next day.

They kept it all day. They said there were no codes. They said it ran fine all day long for them. They used it to run errands with a scanner hooked up. It was the old " can't fix it if it ain't broke". I went home $85 and a quarter tank of gas lighter. Two days later the van quit altogether.

The AAA tow guy got it started by thumping on the bottom of the gas tank while I cranked it, further proof it was indeed the fuel pump. I bought a pump from an internet store and installed it myself, saving at least $400. The nylon mesh filter sock on my pump was virtually blocked with dark varnish-looking material. Other than that the inside of the tank was clean as a whistle. I assume the pump wore out from straining against a blocked intake filter. I was also in the habit of running the tank down to E before refilling, something Chevrolet advises against because the upper pump bearing will overheat when it isn't submerged in gas. I know better now. I also replaced the filter. The van ran great again. I did feel a little uneasy though, because I don't understand how a failing pump would account for stalling when pulling out or going around corners. But there was no doubt it needed a pump.

Fast forward two months and 4000 miles, it quits again pulling out from a stop. It won't restart. I try on and off for a half hour and it won't start. My wife comes to get me, and an hour after it first quit, it starts. I drive it home and park it. The next day it won't start. Or the next. This time I can hear the fuel pump running. So for the time being I'm going to assume it isn't a fuel problem I'm having this time.

I pull off the doghouse to take a look at things, and pull the coil wire out of the dist cap to see if I have spark. I crank it and I do indeed have spark, and not only that, doesn't it start right up! Figures. So far I've proved nothing and I've fixed nothing, but it runs. How frustrating.

I pull the plugs. They are original (127,000 miles) so I replace them, though I don't believe they have anything to do with my problem. I replace the original cap & rotor though they don't look like they're a problem either. My 97 isn't experiencing that moisture in the distributor problem I've been reading about online. And never at any point in all this did my van miss or start hard. When it ran, it ran great, and when it didn't, it didn't. I'm at a loss.

So, since it's running again, I use it for two days straight with no problems. On the third day it won't start. I'm really discouraged and disgusted now. I love how this vortec van runs, so much more than my 92 Astro, but I'm about ready to trade it in on something else.

I take one last stab at it. I pull the doghouse and check for spark again. There is none. No spark. Now I'm getting somewhere, maybe. I'm working outside because I can't get in the garage because the van won't start and I'm cursing the waning daylight. Then, as I'm cranking the engine and simultaneously pushing and pulling on harnesses and wires and components, I see arcing tracing down the coil tower and coil body! Now that it got a little darker outside, I see it! I have a bad coil, definitely!

And I'm now back on the road.

That still doesn't explain why it quit while pulling out from a stop though.
Coincidence?
Avatar
Lowtech55
January 15, 2008.




Harder throttle requires more from the coil. If it is borderline, then under high demand it will short out

Tiny
Jack42
Jan 15, 2008.


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