1996 Mark VIII Variable Load Control Module

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bigdrum

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Hi. I'm new to this forum. I've got a problem with my 1996 Lincoln Mark VIII. It idles at random speeds. When given gas, it pings like someone threw a fistful of marbles in the engine. It sputters and spits like the timing is off.

Timing has been checked; it's okay. Intake was leaking, and gaskets were changed. Changed cam position sensor and crank position sensor. Mass airflow sensor tested okay. Compression on all cyclinders tested good. Tuned up with new plugs and wires. The car hasn't set any code (i.e. no "check-engine" lights come on).

Now I'm being told to check the "Variable Load Control Module," which I hear is extremely hard to find on the market. I'm wondering if anyone else has had a similar problem, and whether anyone can give an opinion about whether this module might be the source of the problem.

Thanks.
Ed

P.S. I have a 1994 Mark VIII parked with the same problem!
 
according to this cut and paste i pulled from the service dvd,that wouldnt do it????

""""Variable Load Control Module
The variable load control module (VLCM) controls:

the cooling fan motor operation and speed.
the A/C clutch operation.
other non-A/C functions.
It also increases and decreases the cooling fan motor speed as necessary, depending on the refrigerant system high-side pressure.
Turns the A/C clutch circuit OFF if the high-side pressure exceeds 2930 kPa (425 psi).

--------------------------------------------------------------------------------
""""""""""""








bigdrum said:
Hi. I'm new to this forum. I've got a problem with my 1996 Lincoln Mark VIII. It idles at random speeds. When given gas, it pings like someone threw a fistful of marbles in the engine. It sputters and spits like the timing is off.

Timing has been checked; it's okay. Intake was leaking, and gaskets were changed. Changed cam position sensor and crank position sensor. Mass airflow sensor tested okay. Compression on all cyclinders tested good. Tuned up with new plugs and wires. The car hasn't set any code (i.e. no "check-engine" lights come on).

Now I'm being told to check the "Variable Load Control Module," which I hear is extremely hard to find on the market. I'm wondering if anyone else has had a similar problem, and whether anyone can give an opinion about whether this module might be the source of the problem.

Thanks.
Ed

P.S. I have a 1994 Mark VIII parked with the same problem!
Click to expand...
 
Moes8 said:
according to this cut and paste i pulled from the service dvd,that wouldnt do it????

""""Variable Load Control Module
The variable load control module (VLCM) controls:

the cooling fan motor operation and speed.
the A/C clutch operation.
other non-A/C functions.
It also increases and decreases the cooling fan motor speed as necessary, depending on the refrigerant system high-side pressure.
Turns the A/C clutch circuit OFF if the high-side pressure exceeds 2930 kPa (425 psi).

--------------------------------------------------------------------------------
""""""""""""
Click to expand...

Thanks for the info. That explains a lot. I did test by replacing the original module with one from a 1993 Mark VIII I got at the parts yard. The car wouldn't start at all, so I put the old one back in, and it's back to its horribly-running self now.

Ed
 
The relay module controls three functions, based upon input from the pcm. A/c clutch function, cooling fan function, and fuel pump function. Have you checked fuel pump pressure? Also, how about tps output?
 
This may sound strange but I have to wonder if you have heavy carbon buildup on the pistons and if the IMRC's are stuck. Sticking IACV might cause part of the problem with the idle. Have you cleaned it yet?
 
AHD said:
The relay module controls three functions, based upon input from the pcm. A/c clutch function, cooling fan function, and fuel pump function. Have you checked fuel pump pressure? Also, how about tps output?
Click to expand...

Sorry for the late reply.

I went ahead and replaced the fuel pump and TPS ... no change in performance. There are only 3 things left to check, as far as I can ascertain: EGR valve, NOX unit ... and whatever it is that controls the timing. I know where the first two are, but I don't know what controls timing nor where the controlling mechanism might be located.:confused:

Thanks for all your help!
Ed
 
problem

what octane fuel do you have in the gas tank.... pinging is bad ju ju. fuel pressure isnt the problem what we have is a predetonation problem here... possibly some bad fuel from your last source. the only other thing is knock sensor... im not aware if the mark viii has one... although im pretty sure it does. something has your timing too advance or your fuel is not right.... thats all i can think of at the moment
 
The fuel pumps on these cars are either on or off (i.e. they're not variable-speed). Since the car is running, the VLCM is working, and it's almost certainly not causing your problems. Mine crapped out and prevented the cooling fan from turning on, but the car ran perfectly otherwise.

Did the garage tell you that you don't have any codes because the CE light isn't on? If so, find a competent mechanic. The computer can, and often does, store fault codes without turning the light on. And if the mechanic didn't run a fuel pressure test by now, he needs to find another line of work. Low fuel pressure will cause pinging and the other drivability problems you mentioned. And a clogged filter, obstructed line, bad fuel pressure regulator, etc. could easily be doing it.
 
plymouth383 said:
what octane fuel do you have in the gas tank.... pinging is bad ju ju. fuel pressure isnt the problem what we have is a predetonation problem here... possibly some bad fuel from your last source. the only other thing is knock sensor... im not aware if the mark viii has one... although im pretty sure it does. something has your timing too advance or your fuel is not right.... thats all i can think of at the moment
Click to expand...

Two tanks of Chevron premium have been run through it last. I think the Mark VIII has a knock sensor, possibly located under the intake. As soon as I find it, I'm going to test that. We had the car on a scope. At idle everything looks fine. As you start to give it gas, the pattern deteriorates until the spark is all over the place. This is what leads me to believe it's something electronic. Of course, at this point .... ???

Thanks.
Ed
 
segxr7 said:
The fuel pumps on these cars are either on or off (i.e. they're not variable-speed). Since the car is running, the VLCM is working, and it's almost certainly not causing your problems. Mine crapped out and prevented the cooling fan from turning on, but the car ran perfectly otherwise.

Did the garage tell you that you don't have any codes because the CE light isn't on? If so, find a competent mechanic. The computer can, and often does, store fault codes without turning the light on. And if the mechanic didn't run a fuel pressure test by now, he needs to find another line of work. Low fuel pressure will cause pinging and the other drivability problems you mentioned. And a clogged filter, obstructed line, bad fuel pressure regulator, etc. could easily be doing it.
Click to expand...

The first thing we did was change fuel filter and checked lines, regulator and pump (pressure/flow). The pump tested okay, but on the low end, so we replaced it. Checked for codes continually, but nothing there. Changed or checked just about every sensor on the car. There's not much left. Does Mallory make an ignition system for this car? :)

Thanks.
Ed
 
bigdrum said:
The first thing we did was change fuel filter and checked lines, regulator and pump (pressure/flow). The pump tested okay, but on the low end, so we replaced it. Checked for codes continually, but nothing there. Changed or checked just about every sensor on the car. There's not much left. Does Mallory make an ignition system for this car? :)

Thanks.
Ed
Click to expand...

i am guessing you didnt actually change the pcm yet?


might be kaka
 
Moes8 said:
i am guessing you didnt actually change the pcm yet?


might be kaka
Click to expand...


No, I haven't changed the pcm. I don't even know where it's at. Sounds like a good idea though ... guess I'll go huntin'.

Thanks.
Ed
 
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