Topic: Mid-90s Chevy truck questions

[heffay]

I've got a 96 c1500, reg cab, short bed, with the 4.3L v6.  It has been de-badged and repainted, and I'd like to find out if it is a Silverado or W/T, etc. 

Are there defining features, or can any of you guys decode the VIN?

As an aside, I drive the truck an average of 150miles per day for work, with about a ton of materials at all times.  Its been a great truck.  I bought it with 156k last June and it now has 184k.  Only maintenance has been replacing a blown stock radiator, which is pretty damn good for lasting almost 20 years in Phoenix!  It gets about 15.5mpg in town, loaded down.  If I had it to do all over again, I'd still get the v6 (unless it was 4x4 or ext. cab).  With 3.08 gearing it doesn't get up and go from the lights as well as some other trucks, but it rolls down the freeway at high speed very well.

There has been one problem all along though...
When it has rained or is very humid, it cuts out.  The first symptom is at about 70-80mph, only at low throttle when its just keeping speed, it will cut out.  As it gets more humid, or has rained a lot recently, it will cut out a lot while getting up to speed.  It will also act like it doesn't want to go up gears (auto) but will eventually shift at higher than normal RPMs.  During that type of cutting out it does it most when trying to shift up.  After driving for an hour or so, the symptoms will go away.  Ideas?  I have mine, but I'd like to hear others before I steer anyone's train of thought.

Thanks for reading

[heffay]

Here's the Red Hot Rod...

[FuZZie]

If that 4.3 = 60 deg v6

It has a flaw in the upper gaskets, causes the water galleries to leak into the motor affects all pre 05 versions I think (updated gasket set is available). Do you know or have ever noticed any kind of stop leak product in the coolant (dealers seemed to duck the upper job with this) a lot of the time it would work but had the side effect of plugging up the water galleries in the head gaskets.

I've no idea if it had anything to do with the rad... but any cooling issues on the 4.3 and I go right to look at this (redone 3 so far).

You have a code reader?

[heffay]

No codes, its an odd problem, and hard to track because its so intermittent.  I thought it might have been fixed when I replaced a bad vacuum tube, but its still there. 

Its always cooled just fine, stays pretty low actually for Phx.  It just developed a leak in the radiator seam.

As far as the motor, in 96 the motor went to the Vortec and gained 35hp over previous models that had 165hp.  I'm thinking by your description, my motor probably isn't subject to that problem. 

I think its electrical.  Motor is super strong, even during the cutting out.  I thought it might be a cracked dist. but nope.  When its not ridiculously hot out I may spend a few hours going thru all the connections and clean them up.  That task seems daunting and unrewarding tho. 

[scottly]

My first thought is the distributor cap. My Toyota v-6 has had similar symptoms; it turned out in my case to be dust on the cap, that would arc-over when damp. I finally caught it happening one time at idle, with the hood open. I heard a "snap" every time it missed. I merely wiped off the cap, and it fixed it, at least for a while. If you have already replaced the cap, the next thing I would look at is the spark-plug wires. Check them with an ohm-meter. General rule of thumb is 10K ohms per foot of length. Usually, a bad one will be completely open. I've had cases where the end of the wire was completely burned off at the spark plug end.

[FuZZie]

Sorry I think I've mixed the numbers, 3.4 and 4.3 backwards, 4.3 =90 deg and 3.4 = 60 deg. 

[DH]

My first thought is the distributor cap. My Toyota v-6 has had similar symptoms; it turned out in my case to be dust on the cap, that would arc-over when damp. I finally caught it happening one time at idle, with the hood open. I heard a "snap" every time it missed. I merely wiped off the cap, and it fixed it, at least for a while. If you have already replaced the cap, the next thing I would look at is the spark-plug wires. Check them with an ohm-meter. General rule of thumb is 10K ohms per foot of length. Usually, a bad one will be completely open. I've had cases where the end of the wire was completely burned off at the spark plug end.

+1 Get an empty spray bottle (409, windex ) etc. and fill it with water.
Mist the dist cap, coil and wire, and all the wires along their length, boots included. Note any misfire.
Move a grounded probed test light along the lengths of the misted wires at a distance
of about 1/8" away. Same thing on the dist cap. Look for arcing. Check dist. rotor
while you're at it.

[333]

There's a VIN decoder over at chevroletforum.com.  You gotta join, but it's worth it.  They know Chevy's like we know SOHC4s.  The decoder is a sticky  in "General Discussion Forums", then "General Tech".

[heffay]

thanks guys... 333 that's perfect, i didn't even need to join, actually.

its a...
1996 Chevrolet C/K 1500 Reg Cab Sportside 117.5" WB

why would they call it a sportside?  i'm assuming the WB is widebody?

[fmctm1sw]

thanks guys... 333 that's perfect, i didn't even need to join, actually.

its a...
1996 Chevrolet C/K 1500 Reg Cab Sportside 117.5" WB

why would they call it a sportside?  i'm assuming the WB is widebody?

Was "Silverado" just a trim level maybe?  Isn't "sportside" where the bed is narrower because the side of the bed is pushed in past the wheel wells?  I'm not sure the VIN would tell you that.  I think they were just 1500, 2500 or 3500 (C=2WD, K=4WD).  The 117.5" is the wheelbase.  Do you know anyone with a scanner that will read live data?

edit:  sportside: http://www.carsct.com/pics/8415B8.jpg

Here's the VIN info for 1996.  Trucks at bottom:  http://service.gm.com/dealerworld/vincards/pdf/vincard96.pdf

[heffay]

What you refer to has always been "stepside" to me.  When I search images for what the vin decoder spit out, it comes up with both the stepsides and typical bed sides.

From the wiki search for chevy silverado... Although General Motors introduced its first pickup truck in 1930, the term "Silverado" was a designation used only to detail the trim for the Chevrolet C/K pickup trucks and Suburbans from 1975 through 1999.

No real time scanners... I know basically no-one here, I have one friend aside from my wife that lives w/in 25 miles of me.  Sad, I know. 



Some good suggestions here, but one thing to keep in mind... it idles perfectly, so trying to troubleshoot in the driveway doesn't work.  The truck has to be on the go before the symptoms will present themselves.  Except for when trying to start the truck after a rainstorm, like this morning, I had to crank for 30 seconds if not more before the truck would try to start.  It was just cranking and cranking, seeming like one part in the equation was not there (air/fuel/spark).

Normally (when not very humid or rainy) the truck will start on the first or second revolution of the motor and idle/drive great.

[Really?]

I had a somewhat similar problem with my Explorer twice.  The part that does not fit in is the humid part.

I could be driving and at about 70, it might act a little sluggish and feel like it cut out a bit but it would keep going.  If I turned it off and back on shortly after, it would just crank over and not start.  If I waited 10 minutes, it would start up like nothing happened and go for weeks before it would happen again.  Over some time, it became more frequent and the time to wait stretched to about an hour an a half.

The Explorer had about 128k miles on it and I got it from my MIL.  She had never changed the fuel filter.  I changed the fuel filter and the issue was gone until about a year/30k later, one time.  I changed the filter again right after that and it has not come back.

I have also read that the fuel pump is in the tank and uses the fuel to cool the pump.

Just a thought Heff.  Your statement of "It was just cranking and cranking, seeming like one part in the equation was not there (air/fuel/spark)" made me think of that.

[heffay]

my guesses are exactly what everyone here has proposed... cap, wires, plugs and/or fuel pump or filter... the fuel pump has always made a mechanical high pitched whine.  i'm glad we're all pretty much on the same page cuz, i'll probably just start replacing those parts, as I can find the time and money.  with 184k miles, and 25k since I've owned it with only oil changes, it needs those parts to be refreshed anyway.

[333]

You should join up and pose your issue over there.  Here, you're asking an SOHC crowd that only a fraction of even own a GM, much less a GM pickup.  There, you can describe your issue to people who only have GM pickups.  You have a much greater chance of finding someone who has had the same issue.

And you could probably get the right answer to this, too.  But I think that sportside or styleside is just the opposite of stepside.

[heffay]

I trust this forum much more than any chevyheads 
Good point though.

[333]

I've been a member over there for a couple years.  They're one of the better forums.  Currently, I belong to 18 different forums.  SOHC is at the top of the list, but they're up there too.