3.8 V6 no spark

[Just a Guy that cuts wood]

2000 Buick park ave The full story . Last year car just died ( no code ) wound up ICM under the
coil packs went out .Replaced with used parts. Six months ago random
misfire # 4 I install plugs and wires clear codes and no more trouble Two
weeks ago random misfire # 4 code ( no spark ) with timing light replaced
all coil packs and new ICM under packs and tested fuel pressure . Good for
a week. Last week No spark no code . Install crank sensor car ran fine for
two days . This morning no spark no code !!!! SHOOT ME Whats next?
Why no codes tripping ?

 

[blades]

Bad primary ground or short circuit. worst case is something leaking somewhere on a computer module. Was that a Pooo4 code as that is a fuel volume regulator circut issue.
Have to remember that codes are a result of a problem not the problem in most cases. so one looks at codes in relation to sequence of operation.
ICM - Ignition control Module

 

[Just a Guy that cuts wood]

Bad primary ground or short circuit. worst case is something leaking somewhere on a computer module. Was that a Pooo4 code as that is a fuel volume regulator circut issue.
Have to remember that codes are a result of a problem not the problem in most cases. so one looks at codes in relation to sequence of operation.
ICM - Ignition control Module

No trouble with fuel or fuel pressure P0304 code is the only code no codes after coil packs and ICM
only two things left cam sensor or ECM computer
unless short some place
car was never in a crash wires are still in plastic shields Ran a second ground from the white wire on ICM (ground ) no spark
only other would be jump time 210 thousand but that would trip a code ( should )

 

[PasoRoblesJimmy]

The 3.8L V-6 in my 1996 Pontiac Bonneville kept getting a random misfire code. The wet plastic intake manifold was letting a small amount of coolant leak into the cylinders. Removed and replaced the plastic intake manifold and gasket, and no more problem.

The 1996 Buick LeSabre had the same 3.8 V-6 engine and same plastic intake manifold. The OEM intake manifolds on these vehicles are notorious for failure. If you have a similar design of intake manifold, you might have the same problem.

A secondary cause of a misfire code could be a clogged fuel injector. However, a clogged fuel injector will also throw a lean mixture code.

FYI, there is a Technical Service Bulletin (TSB) on your vehicle.

TSB #03034
NHTSA ID #10003430

• Date Announced:JULY 01 2003

Summary: ENGINE COOLANT MAY LEAK AT THE UPPER INTAKE MANIFOLD THROTTLE BODY GASKET, OR AT THE UPPER INTAKE MANIFOLD TO LOWER INTAKE MANIFOLD TO LOWER INTAKE MANIFOLD GASKET. THIS CONDITION MAY RESULT IN A LOW ENGINE COOLANT LEVEL AND HIGHER ENGINE

 

[blades]

Forgot about those lousy plastic intake manifolds had replace them on both of my folks Buicks- v-6 units - also seems to be and industry wide issue not limited to gm. wet cylinder short out plug till maybe things get hot enough

 

[Just a Guy that cuts wood]

I ran a pressure test on on coolant pump up to 18lbs left on all day
held cold would love to try it hot but still no spark
to cold to mess with today

 

[PasoRoblesJimmy]

Forgot about those lousy plastic intake manifolds had replace them on both of my folks Buicks- v-6 units - also seems to be and industry wide issue not limited to gm. wet cylinder short out plug till maybe things get hot enough

There was a class-action lawsuit over GM's lousy plastic intake manifolds. Hot EGR gasses burned a hole in my OEM intake manifold and the engine hydrolocked when the cylinders filled up with coolant. Hydrolock from cylinders full of coolant can throw a rod though the side of your engine. Aftermarket intake manifolds, such as those made by Dorman, are far superior to OEM.