93yellowta

Okay have heads and cam put in with bigger injectors/t.b. and accel 300+ ign. did not gain any more power.. atleast when I went to the track my best time was only .10 sec. better and 3 mph. gain. replaced all plugs/wires ..no intake or vacumn leak. but on my datalogger my map sensor is reading 2.8-2.9 volts at idle, and drops when going wot... is that right? could that be my problem, I have a madz28 tune, still getting surging, getting dynotune on july 1st. hopefully that will help it, because the tune is off alittle I think.. iac count is 65 at idle.. 02's are fluctuating right.. throwing no codes.. tps is showing .55 at idle... could the opti have been put on wrong throwing the timing off? I am not picking up any knock retard at idle or wot.. and at idle showing 25-27 spark advance... is that the timing, and does that sound right... just really frustated at not gaining any power? any ideas.. I have a datalogger so I can give you most of the readings......thanks..

Injuneer

2.9V at idle would be about 65kPa. That correspopnds to about 10"Hg vacuum, and seems to be a bit on the low side of vacuum for the 306 in a stock displacement engine.

When you say MAP voltage drops when you go WOT, something is screwed up. MAP should approach barometric pressure (about 100kPa - unless you live at some high elevation), and that would mean a MAP voltage closer to 4.9V

Hard to tell if that is the correct timing at idle... since your tuner will have altered the tables to reflect the cam. However, if the MAP is higher at idle than the tuner estimated, it might be giving you some additional advance.

It would be easier if you gave the MAP readings in kPa, rather than Volts.

93yellowta

it was reading 62 kpa at idle, that is on a snap on scanner. I can't get on that one anymore, my autoxray only does it in volts for some reason... could it be the tune making the map read so high?

and could that be my powerloss?

the car is not backfiring or feeling sluggish and when getting on it, it comes alive, just not much better than stock if any///

93yellowta

oh yeah, I live in missouri, so not very much elevation.

bubba24

yah my map does the same at idle warmed up it might be no more than
1.1v and if I slowly bring up the rpms it will just drop in voltage. If i give it a quick snap it will jump to about 1.6 but just go wacky and still not even get anything close to 4.5. So i ordered a new one will c what this new one does.

93yellowta

well I put in a new one did not change anything.. finally got my car tuned better, did not change the way the map reads. car runs really good now, some cam surging, but I guess with the 306 cam that is pretty normal. still 10" hg of vacumn. at idle. no intake leaks, so I don't know...but runs good.

plattted

what did the 'tuners' do to resolve the problem? I'm glad that the problem is fixed!

93yellowta

he had to change the fuel settings/pe settings? , they were all out of wack...so much for mail order tuning... much better having it done with the car there and to take it out in real driving situations...

LT1_383

I agree. I gained about 30rwhp from a dynotune over the mail order tune. For the price of a mail order tune, you can't go wrong though, even if your not getting full potential, atleast it lets you be able to drive it.

93yellowta

that's true.. because when I had the h/c put in in Joplin MO. my car wouldn't even start on stock tune. atleast the madz28 tune got my car back home, about 100mi. away. but was running really lean...