I'm still running a stock regulator and last week when I checked it was right at 43.5psi

 

You have mail. fergy

All I could see that was much different from what I do is that your inector offsets were quite a bit different from mine.

 

One swapped engine harness later, no improvement. At least now I have the piece of mind knowing there was nothing damaged in the old one I guess.

Does anyone know if 92-95 MAP sensors are interchangeable with 96-97 units?

What about ignition control modules?

I was doing some thinking and it is possible that my MAP sensor and ICM are from earlier engines.

 

Dan, I got your email the other day sorry I didnt get back to you right away.

Try swapping your maf sensor out. I looked back over your logs and your car is reporting ALOT of air for idle. Its showing like 18.5g/sec from the maf on some logs. That is pretty high, it would also sort of explain why the car runs so rich under wot even though you should be able to change it with the pe tables.

I think the trick we tried on it telling it that it had smaller injectors that pulled all that timing, is some sort of quirk in the pcm. If the pw looks way too low for the airflow maybe it pulls alot of timing and assumes something is wrong?

The only thing the map sensor would really effect would be the engine timing. That will not make you look rich on the wbo2 afaik. Should not be a factor under wot conditions. Since it seems you have a wideband.. what is the car showing under normal cruise conditions?

 

I will try swapping the MAF with the one in my brother's 95 Camaro. The AFR while cruising stays in the low 14 to low 15 range. It is constantly jumping back and forth inside that range.

I am not really worried about the MAP sensor anymore, it seems to be reading right and what not. So I moved on to ICM. I am about to make a new post on that, check it out.

 

The rich WOT issue has been resolved, the MAF was dirty. Stupid problem I know. Should have been one of the first things I checked.

I did have a header primary that was close to the k member and did show pretty bad rub marks, apparently from when the motor rocks. I did some filing on the k member and it has plenty of clearance now, and I verified that is is not hitting. Much to my dismay, this didn't fix my problem. I am still getting random knock retard at idle and all over other random times and rpm ranges

Anyone have any ideas?

 

OK I went and took the car out to test and tune at Mooresville Dragway tonight. I know some of you may frown on this with my knock retard issue, but I wanted to get some good logs of WOT passes. I ran 6 passes, and took 5 logs.

The only progress I really made was finding a good shift point. Last time I was at the track (two weeks ago) I was running 7.92-7.93 at 86.xx mph every pass with the shift setting at 6000. Tonight I tried 6200 and 6300. 6200 was working best. The car actually shifts at about 6500 according to the logs. I shaved off 1 tenth and 1mph running a 7.83 at 87mph with my change from 6000 to 6200.

Check out these logs though. You can see for yourselves how random and erratic this knock retard is. In these passes, nothing in the car or the tuneup was touched at all except for the shift points. One pass has a ton of knock retard throughout the idling, staging, and everything. Another pass has some at idle, then staged and made a pass with no retard at all. And the other logs have everything in between those two extremes.

I put the 5 logs and the bin file I was running all in a zip folder. If anyone wants to take a look at the logs, feel free to provide any input, ideas, or opinions. I need to get this issue resolved so I can actually start learning to tune the car. I think you guys would agree that there is no point in trying when it is doing this random knock retard crap.

BTW they are Datamaster .uni files
MDlogs.zip

 

Check your motor mounts or the a/c line tapping on the hood and things of that nature. Any type of exhaust leaks etc will cause trouble with knock too. Logs look ok otherwise, one of them is a little wierd since it changes from open loop to closed loop mid pass . Other than something making contact sometimes I couldnt really tell you anything besides it being false knock, maybe you could ohm test the sensor or something like that to make sure its in range.

Make sure your torque converter bolts are tight and none of the tin heat shielding is touching the headers etc.

Runs are looking ALOT better with the clean maf, I should have thought of that right off but I always assume everyone cleans thiers as much as I do mine, guess not. Airflow doesnt look so great now with the clean maf, still making ok hp for what it is.

 

LOL that's nice, I didn't notice that.

I know my mounts are good and they are tight, I checked them yesterday. I will check the AC lines today but I am 99% sure they are fine. I am going to test the knock sensor today too, Shoebox has a writeup about it on his site. As for the heat shields, I took them off a long time ago.

Yeah I was surprised it didn't pick up more at the track. My first two passes I ran the same 60', ET, and MPH as I did last week with a dirty maf and AFR in the higher 10s.

I am not real happy with this setup. It's the slowest my car has been of any of the 3 heads/cam/stock bottom end setups I have had. It's down 3mph from my last one.

 

Time for some nice new clean tr5's and then make more runs. I will take a closer look at the log runs tonight when I get home maybe theres something i'm missing. Your timing being pulled like that should hurt your times alot. Have patience Dan fast cars are usually not right out of the gate. There are always alot of things to work out and optimize. I think your timing comes in too fast in the low rpm wot columns. You might try toying with the timing until datamaster reports 37 @ wot up top as suggested by a friend of mine who runs lpe heads. Also from what I have seen, these cars can tend to speed up if you pull just a little timing out before the shift happens.

 

I just got done putting my front sway bar back on and testing my knock sensor and wiring. The sensor is supposed to have between 3300 and 4500 Ohms resistance, mine was at 3900 so it's good. The wiring is supposed to have 5 volts, I got 4.7 but I assume that is acceptable?

I am not sure when I will be able to datalog or tune again. I am going leaving to go back to PA tomorrow and the laptop I have been using here in NC is not my own, I don't have one. So that's where I stand right now.

Again, thanks for your help guys.

 

The diagnostic code is triggered when the voltage - WITH THE WIRE ATTACHED TO THE SENSOR - falls outside the range of 1.5-3.5V. Measure from the single pin in the connector or sensor to the block.

 

That is how I measured it Fred. But I got 4.7 volts?

 

Fergy, look at the graph of your rpm vs airflow, that sucker hits a wall at just past 6000rpm on several of the runs. You're going along tearing up hell and then suddenly you go from 310-320g/s right on down to 275.

I would look into maybe checking the valve springs or thinking about a cutout or something along those lines, maybe think about a cutout. I realize your shift point comes in right there, but I think shes got more rpm in her than you're using. I also seriously doubt that the maf is picking up the shift before the ignition is, also your air fuel doesnt change dramaticly there so that would lead me to believe the maf sensor was reporting correctly. Say what you want about the opti the hi res wheel is wicked accurate as far as production ignition systems go.

Further advice for you next time you go to the racetrack, try and turn up the sampling rate that you are logging at, it takes a really fast rate to get good clean logs of a drag strip run. Freescan can go loads faster than datamaster, you just have to make your own pretty graphs in excel.

If you want to run fast in the 1/8 mile you either need to go to 3.23 gears or taller tires, shifting into 3rd before the lights is killing you out the back door. I'd choose tires over gears due to ease of installation, but you may not gain much hauling a bigger tire down the track as opposed to gearing but the tires will give you a clue how your stall would react to the gearing. I personally do not like the way higher rear gears feel with a stall too much slip that way imo. If you like how it drives the way its set up now the tires are a no brainer.

 

Hey man I got really good news. My dad's buddy has been letting me use one of his laptops while I am down here. I asked him tonight if it was for sale, and he gave it to me. I tried and tried to get him to let me pay him for it, he wouldn't have it. What a guy! I have wanted/needed one for so long. So in other words my data logging and tuning days are not over

I will look into the valve springs. My exhaust consists of Jet Hot LTs, 3" true duals with a X pipe, Moroso Spiral Flow muffs and turndowns at the axle. Kinda overkill for my setup so restriction is definitely not a problem.

I will do that next time. I noticed that it could be changed but didn't know about it so I left it alone.

I'm not worried about 1/8 mile times. I was just going to Mooresville because it is close and convenient. I like 1/4 mile and do that whenever possible.

Thanks for your help. When I get back to PA and get back to work I will post up. Should be in the next couple days, I'll be back up there Saturday.