This is a buddy's '95 mustang GT. I've done this a couple of times with foxbody mustangs without issue. I know the computers are a little different, but since they have the same heads, would 14* be alright with 93 octane?
Chris, with the finicky computer that you're aware of, it comes down to more variables than on a fox (IMHO - I know we dont seem to agree at times).
He very well could get away with it if he doesnt have much carbon build-up in the chambers, his MAF and ECT are clean, it's not insanely hot outside, etc. In other words, if he gets pinging, there are a few things to look at before tossing in the towel and backing timing down.
Now on the chance that he has an AODE, he might have some issues in OD at low RPM.
Just like on a fox, no one can say for sure. But the 94-95 GT processors are just a little more finicky with regard to the ping thing.
Thanks for the advice, fellas. Hissin, I've never had a problem with ya. I didn't agree with you about the TO bearing, but that's the only thing I can remember.
In any case, I advanced the timing to 14* (some dummy set his at 4*ATDC), but I'm hearing a lot of what sounds like pinging, now. The problem is, though, that my friends U-joints and clutch are making similar sounds underneath the car, and I can't tell what's what. So, I'm probably just going to back it off a little and go fix the other stuff first, and then try again.
Thanks,
Chris
Ps. It's fun to play with a stocker again, even if it is an SN95.
It sounds like it was running such low base timing for a reason or he has a slipped balancer. If you didnt hear the noise before the timing advancement but do now (and you didn't change anything else drivetrain-related), it's likely that it's just good ol' detonation.
Some of the ancillary things (sensory input) mentioned above might heed being checked. IAT's are known for growing hair on 'em after awhile. Ditto the MAF's (more finicky than fox MAF's). Index the IAT when you toss it back in for good measure.
FWIW, I mentioned the ambient temps scenario because for some reason, some of these things turn into glorified turds when it gets to be 100*+F outside. I've been playing around with some shadetree fixes myself to help it out.
Set the timing at 14 degrees then undo the ground cable to reset the computer. I have been setting 14 degrees on 94-95 cars using 87 octane for years with no problem. If you get pinging then lower your plug heat range Autolite #23.
another 14* on 87 here. no problems. could be a bad u joint. did it do it before you started messing with the timing. when mine went bad the car would make a clicking noise while coming to a stop and a bad grinding sound when i got on it. it was not as noticable at normal dirving speeds.
I swapped the front u-joint out today, and cleared up the vibration and a noise coming from the u-joint. The clutch isn't making any noise now, so I guess it was just the u-joint.
Today was the first day that I've driven this car extensively. Setting the timing yesterday had me convinced my timing light was bad because it was irratic. Turns out, it was stumbling and missing all day today, and even died out a couple of times. I have already put in fresh plugs, wires, cap & rotor. Today, I replaced the old stock (maybe even original) coil with an accel performance coil.
The stumbling went away, and when I checked the timing again, it was at 19*... yikes! No wonder it was detonating. I guess you shouldn't set timing when it seems to be jumping around too much. Setting the timing was much easier today, and I put it at 13*. Ran like a charm, and no detonation. I'm going to bump it up to 14* tomorrow...