i printed this out last night, & applied it to my DD
it always suffers from detonation upon medium to high engine loads/ throttle tip in, but it goes away upon full throttle
i had the timing set at 4* initial, with the factory, dual vacuum set up...it has 2 lines coming from the carb, one from P.V. & one M.V. (ported vacuum & manifold vacuum), the M.V. goes to a little valve/junction, that has 2 lines going to a temp senser on the Tstat housing, then it goes back towards the distributor, but right before the dizzy, the M.V. line & the P.V. line go into a little can-like junction, then from that, a short single line to the vacuum advance can on the dizzy
my only guess with that system, is that when the engine is cold, it uses the ported vacuum set up, until its warm up, & i think its also there help cat light off since the timing is much less...i think this explains why it runs like ANUS when cold, off idle stumbles, sputters, it barely gets out of the driveway & neighborhood
with the engine warm, it had vacuum at the dizzy at idle...so i think i'm correct on how that system works
well, anyways, i kicked the timing up to around 10* (can't really read the tab) initial, & i bypassed the dual vacuum set up, so its striaght M.V. to the dizzy, BTW the dizzy only has about 15* of rpm advance, & with the vacuum hooked up,at idle its somewhere over 20* (about .75-1.0" past the end of the tab, haha) & the car runs much much better, definetly more midrange torque & top end power, the car almost doesn't suck anymore, BUT it pings more often @ lighter-mid engine loads...but not as loudly, so i think i took a step in the right direction, as the pinging is less intense...& it was much easier to drive this morning cold
also, when the EGR flows, doesn't it reduce the burn time of the air fuel mixture right? i don't think my EGR is working, i removed it & clean the ports & tested it by directions of a Haynes manual, & it does not flow anything, the EGR flows during cruise/light engine loads, am i correct? so maybe the defective EGR is now causing my detonation now, as i got much more timing, but the pinging went down a little
i think i'm going to get a new EGR anyways today...give me something to do
please correct me if i got anything wrong
-Greg...the Exhaust Guy.
I was into Malibus before they were 'cool'.
--'82 alldoor 267 Turbo/200r4/3.73LSD 'malibu5' 'worlds fastest 267 lol'
Undergoing Toyota aluminum 4L V8 swap
-79 Malibu 4dr
-79 Malibu 2dr
-80 Malibu 4dr
-79 Malibu 4dr
-83 Malibu 4dr