got some problems...ideas anyone?

[strkt_&_blwn]

Ok I just took my car for the first test drive since i got it back together after blowing a head gasket. everything seemed to be good at first but after about 5-6 miles or so it started cutting out and back-firing. It was just as it started warming up good. It was back-firing when I was trying to keep it running it seemed like it was loading up. it doesn't really like to idle because it needs to be tuned from the recent mods. which include ported factory heads that are also revalved to .202-.160, comp cams custom ground cam with the proper push rods springs etc., the lowerend is stroked to 383 with dish pistons 8.5/1 comp., factory intake, I have an ATI blower P1-SC I left the 8 psi pulley on it and the 42# injectors for now. The car was originally tuned for the 42# inj. and 8psi with the factory engine and transmission. I also swiched to a 6-speed but i don't have the output speed sensor hooked up yet, the connectors are different I don't know if that would matter or not. I switched to long tube headers and had to lengthen my 02 sensor wires. If i would have misconnected a couple of wires would that cause my problem. I don't think that I did but there's two brown wires on the 02 harness and there's always the possibility. When it started to cut out bad it threw a code but I don't have the equipment to read it till monday. Any ideas are greatly appreciated.

[Injuneer]

According to the 95 wiring diagram on Shoeboxes website, the O2 sensors should be wired:

SENSOR WIRE -> HARNESS WIRE:

tan -> tan (PCM ground)
purple -> purple (bank 2); purple/white (bank 1) (signal to PCM)
black -> black (heater circuit ground)
pink -> brown (heater circuit +12V)

Get it scanned. You really need some scanning software, so you can log the engine operation from cold startup through the point where it starts to run rough. The scan software would also allow you to pull the codes. For the cost of a cable (software is free) its well worth it.

Hopefully when you pull the codes on Monday, it will shed some light on the source of the problem. Just not having the VSS hooked up will set a code and turn on the SES light, though. Sounds like its OK in open loop, but starts to run rough in closed loop, which may point to O2 sensor problems.

[Joe 1320]

I switched to long tube headers and had to lengthen my 02 sensor wires. If i would have misconnected a couple of wires would that cause my problem. I don't think that I did but there's two brown wires on the 02 harness and there's always the possibility. When it started to cut out bad it threw a code but I don't have the equipment to read it till monday. Any ideas are greatly appreciated.

There might be your problem. Did you lengthen the wires between the sensor and the harness connection or did you lengthen the harness after the connection? The reason I ask is that generally, lengthening the wires between the sensor and the harness alters the impedance and will foul up the readings. Also, it's not uncommon for 02 sensors to go bad once a headgasket blows. Any silicones that come in contact with the sensor can render it ineffective. The same goes for penetrating lubricants, they can foul the ambient air sample portion of the sensor and again it's fouled. could be wired incorrectly too. Check the codes asap, but it sure sounds like it could be the 02 sensors. Especially since on a cold start, the 02 sensors aren't in the loop until they heat up and the computer goes to closed loop.... that's when you said it starts running like crap. At least, that's my guess.

[strkt_&_blwn]

Thanks alot guys I'll see if I can't get ahold of a scanner faster and see where I stand. I lengthened the 02 harness between the sensor and sensor connector.

Oh and another question can I take the VSS out of my factory 4L60E and put it in my T-56? Will it stil function properly?

[strkt_&_blwn]

Ok I got ahold of a Snap-On scanner today. I tried to read codes, the scanner wouldn't comunicate with the PCM. I'm guessing that I might have a bad ground somewhere but I'm really kinda stumped on this one. I'm going to print off a wiring diagram and check everything out in between the ALDL and the PCM and the ground. Any other ideas?

[Injuneer]

Was the Snap-On scanner for OBD-I (what you need, even though you have an OBD-II ALDL connector - you need an adapter plug) or for OBD-II (won't work on your 95)?

If it was in fact the correct OBD-I scanner, with the correct 12-pin --> 16-pin adapter, its possible that it couldn't pick up power from the ALDL connector. Check the fuse that supplies +12V to the ALDL, usually the cig lighter fuse.

What year is your T56 out of? All the 94-97 VSS connectors should be the same, irregardless of whether its a T56 or a 4L60E. The 93 T56 had a different VSS completely, and may have a different connector.

[strkt_&_blwn]

the scanner I was using is for up to 99 so i'm pretty sure that it has the capabilities. it has the obd-II adapter plug on it. I'm pretty sure that the trans is a 95 also. It came out of one of Procharger magazine cars. The magazine came out in '96. The car is a Yellow '95 Camaro. The VSS plug on my harness has one clip on each side of the connector, but the one on the trans only has one clip on the top center like your usual plug.

[FroSSty]

Your 95 is OBD-I with an OBD-II style ALDL connector. So you would need the software for an OBD-I car and the connector for an OBD-II ALDL... I think this is what Fred was saying...

[strkt_&_blwn]

Your 95 is OBD-I with an OBD-II style ALDL connector. So you would need the software for an OBD-I car and the connector for an OBD-II ALDL... I think this is what Fred was saying...

Yes the Snap-On reader that i have has OBD-I capabilities. Now the car won't start. I have fuel and spark but I think that my Opti is just messed up enough it's not firing correctly. I had a BAD coolant leak and got LOTS of coolant on it so I'm going to take it off and check it out but I'm guessing that's my problem. well or one of them

[Injuneer]

Yes the Snap-On reader that i have has OBD-I capabilities. Now the car won't start. I have fuel and spark but I think that my Opti is just messed up enough it's not firing correctly. I had a BAD coolant leak and got LOTS of coolant on it so I'm going to take it off and check it out but I'm guessing that's my problem. well or one of them

But are you using the correct adapter plug? You can't use a standard 16-pin OBD-II plug, and you can't use a standard 12-pin OBD-I plug, unless you jumper the wires as shown on Shoebox's site:

[strkt_&_blwn]

ok no i'm not doing it like that. I have the ODB-II adapter plug that plugs right in to my jumper wire from the scan tool. I guess I just didn't read your reply good enugh. The scan tool is picking up power from the ALDL I know that because that is how the scanner is powered and it turns on when i plug it in. But if i'm reading and understanding correctly you're saying that even though I have the adapter plug for OBD-II the scan tool still might not be able to read the PCM because it's trying to read OBD-II. is that right? If so If I try it with the jumper wires as seen in your post injuneer with the OBD-I plug it should work?

[Injuneer]

The OBD-II data pin is not in the same position as the OBD-I data pin in a 1995 ALDL connector.

[strkt_&_blwn]

Oh ok I feel slow now. I'll try using the jumper wires as seen in your pic, and see where i get with that. thanks for the help.

[97Lt1SpecialEdition]

Hey check ya fuse box and make sure that your PCm fuse (10amp) Is not burnt like mine did when my tranny had grounded it self out.

[strkt_&_blwn]

Hey check ya fuse box and make sure that your PCm fuse (10amp) Is not burnt like mine did when my tranny had grounded it self out.

that was the first thing i checked but thanks.


i figured out the comunication problem that was my bad I just got in a rush. I didn't install the personality chip in the obd-II adapter plug.

I had disconnected my battery so it erased all of my codes, so I took a shot in the dark that my "No Start" problem was the opti because of my massive coolant leak. I pulled it out and pulled it apart i think that was my problem it was wet inside and the "optical sensor" was wet. "as mentioned by Injuneer of what could be the problem"