Just got a 2000 regal gs up and running. I don't remember 99 being this much of a pain in the A to dial in. The rundown on this car: I bought the car a year ago as a rolling chassis that had been sitting in a garage for about 5 years or so. Then i got ahold of the engine that was originally in the car, has a comp cams cam in it. Just got around to putting it all together and got it running about a month ago. The PCM that came with the car i was told was tuned for the cam. It cad a 3.25" inch pulley and SLP headers. So during my assembly I rebuilt one of my old transmissions out of my 99 and needed a torque converter so why not upgrade lol, got a zzp 3000rpm stall converter. I knew the stock injectors were maxed out on the 3.25 in pullley and wanted to go smaller anyway so got 42.5lb injectors and a 3.0 pullley. Obviously drained the 7 year old gas out and replaced the fuel filter, as well as the new injectors and i've probably put close to 1000 miles on it now so fuel system is clean. So the tune I started with is for the cam, headers, 3.25 pulley and probably an intake as far as i know. So I've been trying to dial in my air fuel ratios using the russ k method. I used a different method on my 99 but i cant find the write up i followed for that one.
So with russ k's method first i had to figure out how to get the damn MAF AFR % error histogram to work, finally figured that out then figured out filtering so as to not factor in dfco. Car had been running pig rich all the time. First attempt multiply by percent, went way lean, so i backtracked and did multiply by % - half. Got close but still rich all the time. Next step multiply by % - half after another scan and the damn thing went way lean again, my AEM wideband couldnt even read it it was so lean, backtracked again and made a few small adjustments in individual cells, smothing the table etc. Made a edjucated guess adjustment for above 7500hz and this is where I'm at: sitting idle 15.4-15.7:1, steady cruise with minimal load 14.5-14.7:1, steady cruise tcc locked up or uphill 13.7:1, wot 10.5-11.1:1 and off throttle coast 15.7-16.8:1 then dfco goes out of range. I'm mostly ok with this just confused because i can be in the same frequency range with steady cruise and vary from 13.7:1 with load and 14.7:1 without load and I'm not in enrichment or dfco and my 99 was a bit more stable during steady cruise with and without load (maybe because this one is cammed?)
Now for my issues with where I'm at that do concern me. At idle in gear (at operating temperature) she surges a little if I brake torque it up to 900rm its happy desired idle is still set to stock (685rpm at operating temperature) thinking maybe I should bring that up a bit and that should solve this, I'm guessing this is because of the cam, I know most of the mail order tunes for cammed L67s bump the idle up. My biggest concern is on hot restarts, sometimes on a hot restart she's lean and stays lean by probably like 2:1 so 15.7:1 when it is normally 13.7:1 and it stalled on me once at a red light when this was happening, other times on hot restart shes rich by about 2:1 so 11.7:1 when it is normally 13.7:1 this only happens on a hot restart. From a cold start I can drive for hour and this never happens. I'm not sure if it did this with the original tune as i don't think i did any hot restarts before tuning.
So aside from my hot start issue and the variance between load and no load steady cruise i think I'm ready to start playing with timing, i currently have no kr, and yes I know the sensors are working as i accidentally got into the boost a couple times and got some kr while I was tuning for base afr below 7500hz.
So question one. Is my steady cruise variance and idle issue because of my cam or am i missing something with my tune? I have no experience with cams prior to this.
Question two. Any input on my hot start issue? I don't think its vacuum leak or mechanical because its only on a hot restart and not when it gets hot form a cold start and its fine on a cold start.
Question three. Before I get deeper into playing with this and smash my head against the wall as I'm making adjustments to someone else's FUBAR tune as i have no idea if the guy before me had any idea what he was doing, I am a GM tech and i can put a completely stock calibration into this thing for free at work. Should I just do that and start form scratch?
Finally my last question. If I start from scratch or even if I don't for that matter. What should I know about tuning for a cam?
If you've read all this thank you for your patience I've tried to be a descriptive as possible. I don't have a ton of time to be on here and do most of my scans commuting to and from work as i have sole custody of 3 kids and my oldest is 5 so i have very little time to go joy riding in this car for data and am hoping to get it dialed in as best as possible before the snow flies as its coming off the road as soon as salt goes down, i don't want this one meeting the same fate as my 99 which has been reduced to commuter/winter beater duties until the cancer kills her off completely (rockers and radiator support are pretty much gone and now the trunk is starting along with the rear bumper wish i had though of pulling of the plastics during my undercarriage cleanings).
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