PCM Diagnostics & Tuning - Rich Exhaust/Gas smell what is the best solution?

Hello, I have a 99LS1 in my 77 vette. I don't have cats or rear O2. The engine is stock except for a custom intake and MAF. I have a very strong gas/exhaust smell whenever I run the car. When I drive long distances I end up with a pounding headache. My question is if I bought a tuner would that solve all my problems? Would I be able to lean/rich the fuel? I am a carb guy and no nothing of tuning a fuel enjected car. Any help would be great. Thanks, Clay


PS...Running very ruff at Idle after heating up

if the engine is stock you definatly have some tuning issues or something. Even without cats a stock LS1 wont hardly stink when its warmed up.

So if I purchased LS1edit or EFIlive I could fix the problem? Which program is the easiest and best suited for my situation? Will a handheld work? I should have left the old 350 boat anchor in the bitch.... :bang: Just kidding

My TA smelled like that from the factory. It was nasty in the summer when the exhaust would choke us out. And they come tuned rich to prevent detonation. As for which tuner to get, how savy are you with computer cars, or want to become? I think HP Tuner is one of the best pkgs available. You can do just about anything with it, and there a lots of folks on here to answer your questions.

If you're not comfortable, I had good success with my Predator. But I quickly out-grew it.

So if I purchased LS1edit or EFIlive I could fix the problem? Which program is the easiest and best suited for my situation? Will a handheld work? I should have left the old 350 boat anchor in the bitch.... :bang: Just kidding


Correct, w/either of those (also hptuners, www.hptuners.com) you can scan the car and determine where the fueling issues are coming rom and then correct...

There's a sticky here that lists most of the various solutions and provides useful info on researching the products. You'll find that HP Tuners and EFI Live are the main contendors right now, both are easy to use (or at least considerably easier than LS1 Edit, there's still a learning curve though regardless)

Check out the various sites and threads in this section to get a better feel for which you think would accomodate you the best... realistically though You can't go wrong with either

Clay (77vetteLS1),

Visit the following sites:
www.hptuners.com
www.efilive.com

Visit http://www.efilive.com/download.aspx and download and install the software, without a licence it runs in demo mode and lets you can play with the sample logs and sample tunes; also see the tutorials.

HPTuners has some demos and an online manual on their websitsite.

Search the forum for each of these, read the stickies.

You're a carb guy you say...
Sure the PCM and its algorithms is more complex,
but it does the same things: fuel and spark
and also a few other things: fans, gear shifts (A4), engine protection, sensor monitoring, failure monitoring, misfire detection, ...

Once you start using one of the programs, you'll see it's so versatile you really can't do without it.
There is a learning curve, but you'll master it.
There's alot of reading involved.
The forums can help with your questions.
If most of us people can do it, you can too.

And... you'll get your Vette dialed in and understand why it's dialed in; search the forum for 'how to tune' articles, and see the Auto VE tutorial here: http://www.efilive.com/download.aspx#tutorials

My opinion: this software is the best money I ever spent.

Good luck.
:cheers:

Guys, thanks so much for the help. I'm Gonna make the big purchase! Looks like Im gonna go with EFIlive. Just got out of the car and I have the same headache!! Need to get it fixed and I would like to tune what I have before I start bolting on!!

I'm guessing you have an exhaust leak upstream from the O2 sensors. This can let air into the exhaust and makes the O2s report a false lean condition, so the the PCM injects too much fuel.

Clay,

EFILive is coming out with version V2 very soon (end of March probably, they are testing the prototypes);

If you can wait just a little longer, you should probably wait until this comes out since this will have both 'black box logging' and 'black box flashing'
(...and will have other cool features, see http://www.efilive.com/overview_flash2.aspx);
the price for personal version is going to be $699.

it will be worth the wait. :drive:

this means you can use your PC to modify the tune, copy it to the 'black box' handheld unit, go to your car, copy the tune from the black box handheld unit to the car's PCM;

then you can drive around logging to the black box handheld unit (collect data), take the black box handheld unit to you PC and analyze the data and make tune alterations;

so you don't have to lug your laptop to/from your car;

the black box handheld unit can store multiple tunes and logs, and has a square blue LCD display.

Also see this:
http://www.ls1tech.com/forums/showpost.php?p=4197088&postcount=20
http://www.ls1tech.com/forums/showpost.php?p=4271550&postcount=118
http://www.ls1tech.com/forums/showpost.php?p=4271653&postcount=119

Regards
Joe
:cheers:

Clay,

EFILive is coming out with version V2 very soon (end of March probably, they are testing the prototypes);

If you can wait just a little longer, you should probably wait until this comes out since this will have both 'black box logging' and 'black box flashing'
(...and will have other cool features, see http://www.efilive.com/overview_flash2.aspx);
the price for personal version is going to be $699.

it will be worth the wait. :drive:

this means you can use your PC to modify the tune, copy it to the 'black box' handheld unit, go to your car, copy the tune from the black box handheld unit to the car's PCM;

then you can drive around logging to the black box handheld unit (collect data), take the black box handheld unit to you PC and analyze the data and make tune alterations;

so you don't have to lug your laptop to/from your car;

the black box handheld unit can store multiple tunes and logs, and has a square blue LCD display.

Also see this:
http://www.ls1tech.com/forums/showpost.php?p=4197088&postcount=20
http://www.ls1tech.com/forums/showpost.php?p=4271550&postcount=118
http://www.ls1tech.com/forums/showpost.php?p=4271653&postcount=119

Regards
Joe
:cheers:




Thanks for the heads up. I will wait

Also keep in mind that not having cats or an EVAP system are going to contribute to smelling fuel. I tuned my car with HPTuners and it certainly has helped but I stll get some fuel vapor smell from time to time.

I'm not familiar with your swap. What did you do for an exhaust system. If you do have an exhaust leak, it will make things run very funny so I'd track those down asap. I have '99 F-body manifolds on my car and had a heck of a time getting them to seal to the rest of the exhaust system. I ended up welding the manifolds to the exhaust pipe. (No more leaks but removing the exhaust system is a little tougher now.)

Also keep in mind that not having cats or an EVAP system are going to contribute to smelling fuel. I tuned my car with HPTuners and it certainly has helped but I stll get some fuel vapor smell from time to time.

I'm not familiar with your swap. What did you do for an exhaust system. If you do have an exhaust leak, it will make things run very funny so I'd track those down asap. I have '99 F-body manifolds on my car and had a heck of a time getting them to seal to the rest of the exhaust system. I ended up welding the manifolds to the exhaust pipe. (No more leaks but removing the exhaust system is a little tougher now.)


Scooter, I haven't been on the forum for awhile but you did help me a few years back with the swap. Most recently I had custom headers made here in socal and the shop did the install. This might sound like a stupid question, but what is the best way to check for an exhaust leak? Also, when I took the car to have the headers made I was forced to drive the car the fifty miles to the shop with just a Ypipe. Could this have fried my O2 sensors? Also, the header shop didn't put an 02 bung in the passenger side header so I had to do that myself. I drove the car with only one O2 sensor for a long time before realizing he didn't weld one in. Again, could this have fried the one O2 sensor? It is to point I can't drive the car running like this.

Any help would be great,
thanks again,
Clay

Tune it !

A new pair of O2 sensors wouldn't hurt. My exhaust leaks could be heard and felt with my hand when I stuck it near the joints in the exhaust tubing. I'd also recommend pulling the battery cable for a little while to reset the fuel trims and any learning that the PCM might have done while you were running with open headers and only one sensor. All the tuning in the world won't help if sensors are giving you bad information.

-Matt

A new pair of O2 sensors wouldn't hurt. My exhaust leaks could be heard and felt with my hand when I stuck it near the joints in the exhaust tubing. I'd also recommend pulling the battery cable for a little while to reset the fuel trims and any learning that the PCM might have done while you were running with open headers and only one sensor. All the tuning in the world won't help if sensors are giving you bad information.

-Matt

Matt, thanks for the .02. I'm gonna do just that. New O2 and unhook the battery.

Also if you want to erase the learned trims quicker, just turn the ignition to "on" engine not running, and pull the fuse for the PCM for about 30 seconds. Then put it back in, and turn the car off for about 30 seconds, then it'll be clear. Better then waiting for the battery trick =D

Just another trick for your sleeve ;)
Adrian

Update.... I found a very loose bolt in the header and I tightened it. I think that solves the headaches!! But, it didn't correct the engine running very rough at idle when it warms up. I unhooked the battery for about an hour and the problem is still there. I am going to buy a new O2 for the side that had the leak and see if that does the trick. Also, I don't know if I am going out of my mind but the engine seems to run abit warmer. About 10 to 15 degrees warmer. Any ideas?

Thanks for the help