Back in 93, I was one of the first folks to get the MP computer in my 318
Dak.....It went back a couple times for this same problem...
The guys at the shop which "programs" the computers suggested a few things....
Checking for manifold leaks was one of the them.......Pull the breather and
PCV valve......Tape ooff the pcv valve hole and put your thumb over the
breather hole while truck is running......Hold a few seconds......Lift thumb
and you otta feel a rush of air come out.....This supposedly indicates that
all is sealed well....If the airflow is weak or not there at all, you have a
intake leak...
I did this and I dont.....But I DO have the same pinging problem......
I have learned to live with it (unfortunately)....about 4200-4500 rpm heavy
throttle....
The truck runs great otherwise...
At 12:02 AM 12/13/97 -0500, you wrote:
>First question: does the fuel you buy contain an oxygenate? We used to
>have it here in NC 'til everyone started complaining of engine knock, and
>again after having to have major repairs since the detonation will destroy
>bearings. Great for emissions, bad on engines.
>
>Second: How much total advance does the computer allow? My '92 max's out
>at about 3500 rpm and from what I can figure, spark advance stops in the
>early/mid 20 degree range. I get some knocking from 4200 to the shift rpm
>at 4800 during WOT. It's worse in the winter since the air is colder and
>thus more dense. For some reason I can't explain, the computer isn't
>sensing the denser air and isn't adding fuel to the mix so in the higher
>rpm's, it will lean out a bit. I've rotated my distributer a bit to have
>and initial advance at 12 degrees BTDC. After a few minutes the computer
>compensates.
>
>Smitty - KF4UQY
>Raleigh, NC
>
>-----Original Message-----
>From: acasey@io.com [SMTP:acasey@io.com]
>Sent: Friday, December 12, 1997 4:51 AM
>To: dakota-truck@buffnet.net
>Subject: DML: Detonation
>
>Another tech question for the list.
>
>I have started noticing my engine detonating badly as I approach 5000
>rpm. This is a serious problem that will keep me off the track this
>weekend. So instead I will be spending Saturday in the driveway
>trying to isolate the culprit. I plan on doing the following, so if
>ya'll can think of anything else to try or look for please let me
>know.
>
>1. Check all the plugs and plug wires.
>2. Check rotor and distributor cap, (there only about 6 months old).
>3. Disconnect my MSD and switch back to the stock coil.
>4. Check fuel presure
>5. I plan on reading up on adjusting the distributor position in the
> Haynes manuel, and then try playing around with it.
>6. I guess I could try a lower temp thermostat, but the engine is not
> getting hot.
>
>Maybe some of our Supercharged members have run into this before???
>
>Anyway any help would be appriciated.
>
>Alan...
>
>94',SLT,V8,5spd,MP SBEC,Flowmaster,SureGrip,MSD w/blaster
>coil,Pulleys,1.7 Roller rockers,Super Street TBI,Taylor
>wires,Chanpion truck plugs gapped at .40
>
>
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