Finally, was able to run the car with the laptop and actually drive the thing. The DTC 33 is the only code showing up, and as you will see on the log, MAP is high over 70 at most times while it's running. It goes into closed loop about halfway through the log, and all goes to hell. The car smells rich, and seems to load up at idle and in overdrive. The car has recently had an updated tune, due to new 42 lb injectors, new tranny w/ 3000 stall, 255 fuel pump. It has a new 52mm TB, due to the old one having worn out linkage. It has a vaccum canister installed to prevent these problems with low vac. New plugs, wires, and Opti cap. Wiring to o2 sensors, MAP and MAF all check out ok. The car also has an LT4 knock module installed. The MAF has been descreened and ported by previous owner, wondering if this might be part of the trouble. Everything on the car that should be included in the tune was. The fuel pressure is set at 43.5 at least for now. The cam specs again (sorry so long):
Comp Cam Grind 290hr-12
Gross Valve Lift INT .510 EXH .540
Duration at .006 TAPPET LIFT 290 INT 307 EXH
Valve timing at .006 INT OPEN 37 BTDC CLOSED 73 ABDC
EXH OPEN 90 BBDC CLOSED 37 ATDC
Duration at .050 INT 230 EXH 245
Lobe Lift INT .3400 EXH .3610
Lobe seperation 112.0
I can't get the link to show up in this message, BUT here is the web address of the file, it was uploaded in csv format:
http://www.2shared.com/file/2861467/...testdrive.html

 

If the maf was modified and is not bad it should have been included in the tune order sheet and figured in the tune. They recommended getting a factory untouched one before the tune and it would help getting a more exact tune. I got mine on Ebay for around $75 and it helped my car run a lot better.

 

okay,I went back over all the connectors and wiring on the car again last night and I still can't find anything wrong with the wiring so I don't think this is my problem. I would greatly appricate it if someone could look at my data log and point me in the right direction. I am going to purchase a vaccum gauge when I get off work this afternoon and check my vaccum at idle. Thanks in advance for any help

 

Your data log consists of a single line.... it that what you want looked at?

You don't need a vacuum gauge. It's available from the data log. Barometric - MAP = vacuum.

 

I will have to look at the data log when I get home this afternoon. I had about 531 seconds loged. We drove the car at various speeds and rpms so that you would have a good idea of what the car is doing. I also posted the cam specs as you (Injuneer) requested. Thank you again Injuneer

 

Sorry about the last link, here is the correct one:

http://www.2shared.com/file/2866080/.../camtest2.html

 

Okay I am going to be off tommorow and I am going to check the volts to the map, maf and o2 sensors.Could someone reply with the voltage that I should get when I check these. Also could someone please check out my data log I have reposted since the first one did not upload correctly(sorry).We are thankful for any good advise that can be given. Thanks in advance.

 

At least the new one has some data in it. I'll try to look at it, but I got 14 e-mails and 8 PM's this morning, most of them asking for help with car problems, and more than 1/2 of them about looking at data logs.

 

Thank you Injuneer. I will wait patiently for a reply from you about the data log. I know you are a very busy man. You are very knowledgeable about these cars and always seem to be willing to help all that try to help themselves. I know I appreciate your advise and I am sure others do to. Thanks Seth.()

 

I am going to check the voltage to MAF sensor connector.It should be 12 volts correct?Also could the MAF(the one on the car was descreened and ported by the previous owner) be causing the the problems that I am having. I am looking at a Granateli MAF. Any information will be apprecinated. Thanks in advance

 

Getting a Granatelli MAF would probably be about the worst possible way to try and solve the problem. If you think the MAF may be the source of the problem, borrow a totally stock unit, screen included, and try running that.

You want +12V on the pink wire in the MAF harness connector, when measured to the black/white wire.

Adding a vacuum canister will help with external devices, like the power brake booster, but it does nothing to cure the problem of low MAP readings.

 

Got caught by rain, and was unable to check the voltage on the pink wire in the MAF connector, but noticed connectors for #6 & #8 injectors plastic had melted at one point. Didn't notice any damage to the actual wires there, but it did get my attention. Is there any way to check voltage to them? I just want to be sure....what should the voltage be? I'll check the MAF by switching it out tomorrow as long as I don't get rained out badly. After that, I'm out of ideas.....any other suggestions? I'm thinking a chainsaw or cutting torch might be the way to go, we have had it with this car. I'm starting to dream about the stubborn thing.

 

Each injector connector has a pink wire in it. With the key on, that wire should have +12V, when measured to an engine ground (not to the other wire on the connector). The PCM fires the injectors by supplying a ground on the non-pink wire at each connector. You can use a 'noid light to verify each injector is getting as ground to fire it. Or you could put a frequency meter across the injector wires, and the frequency should match the engine RPM/2, if the injector is firing.

 

Thanks for the info. I will check the injectors and maf circuit today and post my findings. If someone gets a chance to check out the data log please let me know what you think. Thanks, SETH

 

Okay everyone, I went outside this morning and changed out my MAF that had been ported, polished and descreened with an un touched GM MAF I borowed from my neighbor. My Iac counts droped to 43 and my MAP droped to 23 ihg and the car ran smoother at idle. I hooked up my friends MATCO determenator scan tool to the car and allowed it to run until it went into closed loop. The long term fuel count on bank2 to was 160!!!! So i scrolled down and took a look at the o2 on bank to and it was reading .430, .360, .240. It never switched from 900mv to 100mv. So I am thinking that the MAF and The right o2 sensor or trash and I have been fighting a problem that has been right here in my face the whole freakn time. Please someone tell me I am right. Thank you Injuneer and Shoebox for all your help.