Idle HC's up

Roc87

11 Second V6
Joined
May 25, 2001
GN usually passes easily. 2 years ago with bad heads (they were seeping coolant) it passed at 11HC of 200 at high, and 28 of 200 at 2500rpm. I've replaced the heads since then, and of course new HG's and intake gaskets. Using an emissions chip, 2 gallons of e85, temp was around 200°, it failed idle test, 399 of 200 and 2500rpm was up also at 64. Cat is only used for emissions tests. The mechanic let me mess with some things after it failed with the machine on monitor. Turned the FP way down, retarded timing an additional 4° on the translator and also leaned out the base fuel. It really didn't make much difference. Going to change the plugs and clean the MAF, but seems like everything else is the same as it was 2 years ago. I don't have a egr, but the local test doesn't require it. Any ideas?
 
"was up also at 64" What is this refering to ?
years ago i had a troubled truck where the cats were too far back. They ran cold and I used a 50/50 mix of ethanol and gasoline to squeak through.
you may actually need to richen it up to let the cat "light off" Is this chip running in closed loop? They cat should be super hot when functioning, you can google it and check with an infer-red thermometer.
 
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Hey Roc, Mike B here.
-Check for vacuum leaks. Un-metered air can bring up HC.
-Check your plugs, an oiled up or misfiring plug can definitely bring up HC.
-Are you sure your cat is still good? I realize it is not run constantly, but something to look at. You can borrow mine if you would like.
-Check compression on your cylinders. I know it is freshly redone, but I also know the history you have had with the ride.:(

Good luck man, will help if I can.

-Mike B
 
Hey Roc, Mike B here.
-Check for vacuum leaks. Un-metered air can bring up HC.
-Check your plugs, an oiled up or misfiring plug can definitely bring up HC.
-Are you sure your cat is still good? I realize it is not run constantly, but something to look at. You can borrow mine if you would like.
-Check compression on your cylinders. I know it is freshly redone, but I also know the history you have had with the ride.:(

Good luck man, will help if I can.

-Mike B

Thought I had found the problem, I have a BOV and the vac hose that goes to it usually goes to charcoal canister and I forgot to hook it up correctly. After cleaning the LS style MAF, changing plugs and routing the vac hose correct, it was better, but still not good enough. For a while it hangs around 80 watching the machine, but then it'll hit in the mid 200's and takes a while but then it goes back to being in the 80's. I'm now wondering if I have a sticking injector? Going to pull a friend's 60# injectors and use his emissions chip next week when that same mechanic is there so I can do a monitor test again before the real thing. Appreciate the help and suggestions. Cat is usually in a box in the garage, only put it on one day every two years, still looks new looking through it, not sure how to check other than that. I have a V-Band flange on my test pipe and the cat, so if I need a new cat that'll have to re-done
 
"was up also at 64" What is this refering to ?
years ago i had a troubled truck where the cats were too far back. They ran cold and I used a 50/50 mix of ethanol and gasoline to squeak through.
you may actually need to richen it up to let the cat "light off" Is this chip running in closed loop? They cat should be super hot when functioning, you can google it and check with an infer-red thermometer.

The up 64 is what the 2500rpm test was showing, two years ago it was 11. Cat is in stock spot, I forgot to take infared thermometer to see how hot cat was
 
Good idea on the injectors.
The only other thing I can think of is weak/bad spark. I have spare ignition module/coil if you need to test.

-M
 
Good idea on the injectors.
The only other thing I can think of is weak/bad spark. I have spare ignition module/coil if you need to test.

-M

Appreciate the offer, it currently has a TR6 ignition on it. If the borrowed injectors don't fix it, I'll try your spare ign.module/coil
 
Do the o2 volts cross count up and down indicating closed loop operation?

Didn't even look at the O2 x-counts, will be sure to check before I go back. Its a TT emissions chip, you should've seen the numbers when I put the regular 6.1TT chip in it, lol
 
If you have a TR6, I am guessing your spark is just fine!

Well, should've known... I pulled Eddies 60# injectors this morning, and got his emissions chip. Swapped those in this afternoon. Just a while ago, I went to start it to drive around the block to warm it up and change the oil, and it idled absolutely horrible. Puffing white smoke out the tailpipe, gassed down oil was coming out of the header to turbo connection along with the crossover connection under the oil pan. Noticed as soon as I turned off the key, that the fuel pressure would drop to zero. Figured, "Great, ecm is fried", so I swap chips to my ecm that has been modified for high & low ohm injectors and now it pops the fuel pump fuse under the dash right when key is turned on. Tried the other ecm and it does the same thing. Tried using the other fuel pump (Double pumper) as the primary and it still pops the fuse right when key is turned on. Plugs don't have 10 miles on them and are soaked with gas. Whats weird is that neither fuse on the back of the alternator (Double pumper hot wire kit from Racetronix) ever blows out, just the one under the dash.
 
I know it is freshly redone, but I also know the history you have had with the ride.:(

-Mike B

So sick of this car, it's always something. I replaced the intake gaskets after the get together at Chucks and it seemed to be running great, until I had to change things up for the emissions test
 
That is....odd.
Sounds like multiple things happened when you swapped the injectors? Based on your description, it sounded like:
Car runs pig rich on 60# emission chip or injector stuck open?
Something is overloading the fuel pump circuit and blowing the fuse. Doing some digging, look at this post: https://www.turbobuick.com/threads/fuel-pump-fuse.283618/ John Spina gives some reasons on why this circuit blows. "The second biggest cause of failure is the No. 3 injector wiring contacting the EGR valve, burning through, and shorting to the ground." Maybe look for something fishy on the injector harness?

Please don't let your car near mine...I don't want the voodoo to rub off! ;)
 
The really weird thing is I swapped the entire fuel rail, wiring, injectors all together. That way it would be easier to put Eddies back together. I've said it before, but I'm serious this time, I'm done with this car.
 
I've said it before, but I'm serious this time, I'm done with this car.
You have said that a few times. :)
-Step away, have a beer and wait a bit.
-My advice, put your old injectors, harness and fuel rail back on. I have a feeling your car does not like Eddie's harness. Get back to your baseline.
-Have another beer.
-Try just the 60# injectors.
-This issue is not even in the same league as the issues you had with your heads...that was real weird. You have the nicest GN in town, don't give up on it. It was the inspiration for my car.

M
 
You have said that a few times. :)
-Step away, have a beer and wait a bit.
-My advice, put your old injectors, harness and fuel rail back on. I have a feeling your car does not like Eddie's harness. Get back to your baseline.
-Have another beer.
-Try just the 60# injectors.
-This issue is not even in the same league as the issues you had with your heads...that was real weird. You have the nicest GN in town, don't give up on it. It was the inspiration for my car.

M

Appreciate the compliment, dang emissions and its tight deadline to keep it registered. Our house reeks of gas now. I may just park it down at my parents place for a long while, and "withdraw from use" for the insurance. Last time I got it running again and went to the rapid mvd they didn't even ask for receipts for repairs why I didn't keep it registered
 
So the latest, there was a pinched wire on the injector harness, have no idea how that would dump all kinds of gas before blowing a fuse. But anyways, thats fixed, started, idles fine, after it blew out whatever gas was in the exhaust its not smoking either. Is a TT emissions chip idle in closed loop, the cross counts aren't barely moving, and my wideband O2 isnt doing much. Wideband shows 10.0:1-12.0-1, and leaned out max at 17.9, nothing in between (12.1-17.8) thinking that much gas in the exhaust fouled both my heated O2 and the wideband.
 
Eric I have a spare AEM wideband sensor if you need it. It looks a bit knarly, but it read the same as my new wideband sensor, just not as pretty.
 
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