'98 Blazer won't start - eats ignition modules

I have a '98 Blazer with the 4.3L engine. For about 1 year it has been running very rough, especially when it is damp outside and it has sat overnight. It usually will run well after about 30 minutes or so.
It has also gotten so bad on 3 occassions that it won't start at all (cranks but won't fire). If the ignition module is replaced, it will then start. Something appears to be taking out the ignition module.
I have replaced virtually (if not all) every ignition component within the last 6 months, including plugs, wires, cap, rotor, module, coil and even the TPS.
It is now dead again, and this time after a shop replaced the module. It is interesting to note that the mechanic said the base timing was way too high as well.
Any suggestions are very welcome, as this is getting pretty bad.
The truck has 104K on the clock.
Thanks,
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Are you Jump starting other Vehicles with this Truck?
Is it a Snow plow Truck?
VDeuce wrote:

--
It Doesnot Take Brains To
Get A High Paying Job!
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
No to both.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
VDeuce wrote:

That eliminates High Current thru the alternator

--
It Doesnot Take Brains To
Get A High Paying Job!
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
This part is called pickup coil. It located uder the rotor which looked like a starshaped with points inward to each other.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the suggestions! It is still acting up, and even the Chevy dealer can't get it to continue to act up in order to perform a diagnosis. It goes away once the engine is warmed up.
So the only way to replace the pickup coil is remove and disassemble the distributor huh...
That is the one part I didn't replace, unless I forgot about it because it was easily replaced, though from what you describe, it would require removing the dist and I know I didn't do that.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
This is often overlooked, as most don't know. There is a another coil on these dist. it is located under the starlooking piece. These coils do age from wear and heat and will short out ruining the ign. module. To replace this coil, you would have to remove the dist. from the engine, be sure to set it at tdc or mark it somehow to get it back in the engine right. You would have to remove the gear from the shaft and pull/push it out from the dist. housing to get at the starlooking coil piece out and replace it. Will have to replace the module also along with it and check the wiring to and from the dist. to be sure it not frayed or shorted together. Once it back in the engine, follow the steps needed to time the engine in it right place.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Is this module in the dist.? if so don't forget to use heat sink grease where it mounts.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

and mounting the module. Whitelightning
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
VDeuce wrote:

Did you replace the pick-up coil?
A bad pickup "can" make the module go out.
~:~ MarshMonster ~:~
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Make sure you use Delco parts. Aftermarket parts are often marginal in quality.
Randy

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.