I have a 1996 Blazer LT 4-door 4x4 (4.3 liter) with approx. 157000 miles on
it. While it has been a great truck for all the years I have owned it
(purchased new), in the last 12 months, it has gone berserk.
Basically, it starts and runs great about 60% of the time, and the other
40%, it won't even crank, much less start. I have had this vehicle into a
multitude of different garages, and no one seems to be able to decipher
what is wrong here. I have had 3 fuel pumps put in in 11 months. I have
also had the wiring completely replaced. I cannot locate the problem, and
neither can a good half dozen ASE certified mechanics.
I was curious if anyone here has had similar problems, or has any idea what
might cause such freakish behavior from an otherwise wonderful automobile.
ANy help is greatly appreciated. Thanks in advance.
freakish things like this can be caused by bad battery connections.
detach the battery cables and inspect them very well...look for thread
damage, worn cables, frayed cables, inpect the threads inside the battery
sometimes if the cable is a little loose the arc's can melt the threads
check the ground at both ends and the bottom of the positive cable.
I had a similar situation with a car - 1987 Olds Toronado. Bad
connection in the dash caused the car to just completely die while
driving down the road! Hit the dash in a certain spot & it would work
again. Never really fixed the problem & got rid of the car. Did you
replace the wiring in the dash? Intermittent wiring issues are a bitch
to track down...
Wiring was replaced from the distributor to the fuel pump, with no result.
I have been doing some research into this problem, and am considering
replacing the fuel pump relays along the firewall, and seeing if this has
Strangely, the problem only manifests itself at startup. Once the truck
starts, it runs perfectly, with no stutter or miss. The trick is getting
it to start.
Run a test on the fuel pump at the firewall first, run a hot wire to the
fuel pump test lead and listen for the fuel pump. Intermitant starting
problem can also be the fuel injector drivers in the ECM but it will get
worse to the point that it won't staart at all. Not very common with the
Blazer but it does happen.
I had a 91 Grand am that would do about the same thing, only it would die at
anytime and cook the ignition fuse and die, replace the fuse and let the car
cool off the car would run fine,. after DAYS of troubleshooting I found that
the wire leading to the ignition module had come out of the wireing harness
and rubbed itself bare on the engine block. When the car was cool the wire
would lift off the block, as the car heated up the wire would soften and
fall on the block and cause my grief.
Check to make sure that you have no wires going to ground that are not
I went to GM school back in 1993. Boy did they ever stress how important
the ground wires are! They said make sure all the seperate ground
connections are made. Do not cut all the eyelets off and crimp them
together. They all need to be seperate even though they are on the same
jesus, mary and joseph
'a half dozen ASE certified mechanics'
doesn't speak well of the 'certification' process, does it ?
look, when it don't crank: main path is battery + to starter to engine
block to battery negative; an auxiliary path is battery + to ign sw to
starter to battery negative
how goddam hard is it to check out a pair of 4-component circuits, fer
if it cranks but won't start, you have 4 (and only four) possibilities: no
spark, no fuel, no compression, or wrong timing
since it DOES start sometimes, we can rule out no compression and wrong
which leaves lakkafuel and lakkaspark
'ASE certified'................big f-ing deal
LOL. To their credit, I have not been charged a dime (except by the guy who put
the fuel pump in the
truck). The mechanics that have looked at it have even eaten the towing cost
rather than charge me.
I apprecaite all the replies here. Looks like I'm going under the hood for some
checks. I'll let you guys know if I can find the problem.
See Training is not a substitute for experience.
It does sound like an electrical issue.
Try looking at the Bulk Head connector that runs thru the firewall. The
MetriPak connectors are notorious for poor contact. You can
try grabbing the harness behind the Relay center and wiggle it and see if the
Otherwise, open up the Bulkhead connector and look for Blacken pins.
I know what you're saying. However, I had the same problem about a month
ago. My problem turned out to be *too much* fuel. My problem turned out to
be the *Fuel Pressure Regulator*. It has a vacuum hose on top of it that
goes into the air intake plenum.....and gas was leaking into it from the
vacuum hose. This is what caused the long cranking to start when the engine
was warmed-up. I actually stumbled on the problem when I was checking the 8
new fuel injectors that I just installed. I was checking them, for leaks.
I had just installed them, and with the air intake plenum still removed, I
turned the key on (ignition only) to pressurized the fuel rail and fuel
injectors to see if I had any leaks. There it was. Fuel was pouring into
the air intake plenum from the vacuum hose on the Fuel Pressure Regulator.
I installed a new Fuel Pressure Regulator, completed the assembly.......and
BINGO! The problem was gone.
If it won't even begin to crank sometimes but starts up others,I would
check the neutral safety switch,then the starter/solenoid,then the
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