So here is what's going on

The car is idling roughly, and when i come to a complete stop, it feels like it's going to shut offf........

Over 3,500 rpms, it gets a slight shudder......

So what's going on? I replaced the driver's side spark plugs, fresh oil and filter.......



Any help appreciated.......

This CRAP is shooting out of the exahust.......

 

just a though, i'm sure some people on this board could help you but since you have an ls1 why dont you try an ls1 forum for motor help.

 

Posting it on an LS1 board as well......Redundency can never hurt, just wondering if people have some general ideas......and/or had similar problems with their 3rd gen motors........

 

looks like it's getting way too much fuel

 

good call. Generally i go by the rule that all a car needs to run is spark, fuel, air and compression. I doubt youre having air or compression issues. I would possibly check your fuel pressure maybe your pump is having issues? Not sure what all that junk coming out of the tail pipes would be looks just like condensation.

 

Sounds like a clogged catalytic converter (or getting clogged) issue.

 

It smells insanely rich, however it's getting fuel pressure of 60 psi of fuel


Trust me, I know for a fact the catalytic converter is not clogged......

 

i bet its a sensor. If its running really rich its trying to compensate for something. Get the ecm scanned and see if it comes up with anything, haha i love my L98 i can get it to flash me the codes.

 

O2 sensor... daggone little things !!

 

for ****s and giggles, take it through emissions? I bet it's an O2 also. Mine was running so rich that I could almost taste the gas from my exhaust lol. Replaced the O2 and things were spiffy again.

 

Can you check the timing on an LS1? I've had a few people come into the parts store I work at and ask about the crank triggered timing....

I know on my car, when it had the wrong knock sensor, the timing went WAY retarded and kinda acted like what you are describing. Maybe your knock sensor(s?) took a dump on you?

 

Passenger side Spark plug.......










Driver's side spark plugs........the one on the right is the brand new one....










Any more ideas?

 

Just curious, but isn't that the one that you just spent a lot of time and money having installed?

 

How are the valves?

 

I had a similar problem w/ my LS1 swap recently.

If you're running K&N or other oiled cotton gauze air filters, likely you have the same issue.

The LS1 MAF sensor is extremely sensitive to the oil from the filters. It doesn't have a burnoff like TPI MAF's do, so even a slight amount of the filter oil will accumulate on the thermistors and throw it off.

I got error code P0101 intermittently, it had a hiccup at around ~3200rpm or so, and was running rich.

The fix was a can of Radio Shack aerosol electronics cleaner. Just remove the MAF, spray it down with that stuff and *DON'T TOUCH* the wires or thermistors. Just spray the stuff across them, let it and the gunk run off, and let it air dry. When it's dry, reinstall it and go for a spin.

It doesn't take much oil to throw it off...my MAF sensor was dry and looked fine before cleaning, but after cleaning I noticed the thermistors were silver where before cleaning they were gold/bronze color from contamination.

Good luck!

 

Thanks for the tip, I'll take it out today after work and see what i can find out........

I ordered MSD ignition wires as a precaution, they should be here tomorrow, so if that doesn't work and the Wires don't work, then it's off to the O2 sensors........

 

See if you can get your hands on LS1edit. It will tell you right away whats up.

 

dude, before you go and blow more money on plug wires, plugs, and anything else,

take the bloody car down to the local autozone or checker, and have them scan your ECM for codes.

ITS FREE!! and will be much more conclusive than us trying to guess your problem. I would guess the problem is a 02 sensor(s) but there is no sense on wasting money guessing at the problem. Esspecially on a engine you just paid 10 grand to have installed.

oh and after you get the problem fixed, your going to need new spark plugs because those are pretty good and fouled.

 

How exactly will LS1-Edit tell you what's up?

At present, it only reads the flash memory from the PCM and dumps a binary copy of the software. You can edit your software, re-flash the modified software back to the PCM...but no scantool.

Cheap solution is www.scantool.net for less than $100 and a laptop, upward from there is AutoTap or EFILive, and then there's HPTuner which has a combined flash/edit/scan toolset for $499 or so.

 

Well I went to AutoZone, Pep Boys and even Firestone Master-Care, all places wanted $79.99 and up just to scan the ECM for codes......

They don't do it for free...

 

If you wanna drive to VA I'll scan it for you for free, lol.

 

I had no idea. I have never used it but assumed it sanned codes as well as every other engine parameter.

 

You left that part out earlier.

People that don't know better tend to assume that "Moderator" title means you're knowledgeable.

 

Lots of novice guys use it to tune heads and cam packages so I geuss it has to tell you somthing about the running status of the motor. Maybe thats helpful maybe its not. I feel ashamed that my suggestion was sub-par.

 

No, in the same way that TunerCat and GMEPro don't tell you anything about the ECM's sensor inputs or control outputs during operation. They all just let you open a binary image and edit specific variables.

And no need to be ashamed for not knowing what you're talking about. If you want to be ashamed, do it for not knowing the diff between editing and scanning.

 

I am well aware of the difference. I made the inaccurate assumption that it did both. No big deal.

 

eh, the ones here in arizona do it for free, had it done twice on my friends 96' monte.

 

i had the same problem it was the o2 sensor.. engine will run pig rich if the o2 is on its way out reporting low voltage.. HIGHLY doubt its a spark problem..

 

I'll throw in my , check your fuel pressure after you shut it off. If it leaks down I'd look at the pressure reg. You MIGHT have a pin-hole in the diaphram.

 

Was the car running correctly before you did this?

Passenger side plugs are fine, driver side plugs are messed up? This sounds too easy. Spark plug wires reversed on #5 and #7 cylinders.

 

10K and you dont know how to fix it.

 

You cannot mess up the plug wires on an LS1. The wires are only a few inches long and barely reach from the individual coil packs to the plug. Just because he spent money on this swap doesn't mean he has to know everything about it. Thats why he paid for the swap. I would be quiet if you don't have an LS1 in your 3rd gen.

 

??? I didn't say anything about money or how much it cost?

You are right that I forgot this didn't have a normal plug wires.
But everyone is ranting and raving that it's a fuel mixture problem, but how could some plugs be fine and others not? Also the fact that this happened after a spark plug change lead me to believe it is an issue with the spark plugs not firing. So forget I mentioned the reversed plug wires and instead, just check the ignition system to the cylinders with fouled plugs. Just trying to help.

I'll be quite now.

 

That was for the reply below yours.

 

Thought so. Just given you grief

Aren't we just the hell raising crowd here?

BTW, I still think it's ignition related. I just can't see how some plugs are fine but others are bad. Maybe they are overgapped?

 

hm..maby its a coil gone bad ..it dose happen. check it with a volt meater

sorry to here about you car being messed up and stuff..

 

OK, so a little update, I got my MSD 8.5mm wires from Summit installed on the car today.......

Picture Below...


The car is running much, much better, however i can still sense a little hesitation while driving, so the problem is not entirely, fixed yet, but it drastically improved the problem..

Next on the agenda, the O2 sensors......

Z28*****, mentioned that it might be a leaky fuel injector on the passenger side of the car, would this cause the situation that i'm describing??

 

Are all the plugs on the driver side black like the one in the picture or just the one? It could be a leaky injector, but that would generally keep one from starting easily as it would flood the cylinder. It's hard to tell, but the other picture of the plug from the passenger side looks like the car is running real lean. You may have something that is partially clogging the fuel system somewhere, you may want to look at changing the fuel filter before spending 70 bucks on O2 sensors. Plus I agree with everyone else about getting the codes scanned, the computer stores codes that won't throw a check engine light which may shed some light. Also if you know someone who has a datalogger for the LS1's you may want to look at getting your hands on it and seeing what is actually going on while the car is running.

 

I already changed the fuel filter and it had no effect

2 of the 4 spark plugs on the right side are like that........unfortunatly, i can't take out the other two with my set of tools, so i can't be 100% sure they aren't black too....

However the 1st and 2nd to last spark plugs were black like that.........

 

You said the new wires might have fixed the problem, but you still have the fouled plugs in there. Now that its running better with the new wires, change the plugs. I have some barely used NGKs and 02s if you want to use them for trouble shooting before you shell out some cash. BTW, I can change LS1 plugs in < 30 mins. Just buy a u-joint for your rachet. Let me know.

 

Hey man, thanks for the help, I'll get in touch with you tomorrow afternoon-ish or maybe Monday evening, work on weekends.....

 

Welcome to Fuel Injection, I'll be your host.

Get yourself some data logging software and a laptop,
then get something to program your ECM.

I'm not a LS1 expert, so I'm not going to "assume" what works and what doesn't, but I will "assume" your car is out of tune.


-- Joe

 

left side plugs being black sounds like an injecter problem i have a vortec that did that and found one of the poppets came loose and was filling the intake up with gas, costly but that was the problem

 

just out of curiosity, what kind of warranty did you get on the motor when you had roy install it?

according to the autozone commercial i see all the time, they will scan codes for free.

 

Not here in cali, shops complained, so the state stopped Autozone from scanning for free. What they do now is loan you the scanner with a 100% refundable deposit.

So Flynlow, hows it running now that you got a few days on the new parts?

 

No good democrats..

-- Joe

 

Did you work on your maf - I mighta just over read if you did. I have a friend with a Hyundai Tiburon (I know its not ...) but he was having the exact same issues as you after he installed an aftermarket CAI. He took off his maf and cleaned the hell out of it and his problems were taken care of. They're touchy creatures

 

Ya, I was reading this thread and noticed nothing was said or done about the MAF suggestion, like it was totally blown off. Sounds like something worth trying, to me...but I don't know.

edit: actually, I see now that he said he'd try it but I don't see a follow up as to whether he checked or not.

 

Well again, thanks for the help.

The maf was taken off the car and cleaned, so that's not an issue anymore, however the car is now running much better.....

I have noticed a some sputtering when i'm under WOT? Any ideas on what might still be causing that?

 

Well since we repalced several parts that were bad and its still acting up, I will say its time to log some runs using an OBDII scanner like Autotap. Unfortunately I don't have A-tap yet, but post on the western board of LS1 and LS1tech to see if someone local is willing to log some runs.