Question: emmisions help

[CHERRYPICKER]

Hi all, new member from Canada
93 LT1 , trip black convert, 120 k miles

Have been reading some excellent stuff on this site, you guys are unreal.

Bought this car out of Vegas 2 years ago, passed safety and emissions here after a couple of lights were changed and the daytime running lights were set.

this year the car would not pass..passed at 2000 rpm(barely) but failed at "curb idle" ( 625 rpm )..HC ppm 334 , limit 200.......CO% 1.79, limit 1.00

the O2 was changed with no affect.

about a year ago i had the ECM konk out (ASR fault...no start) and had it redone at Cardone, when it came back it was not the exact same ECM that i sent, but it was the same part # and when installed, all was good.

I just checked the injectors and 5 of them are 13.3, one is 10.4, and the other 2 are 13.1

mechanic said it was running rich.

Am considering changing the injectors but from some of the other posts here i have a couple questions:

It looks like with my 93 that all that i have to do is relieve the gas pressure and take off the fuel rails...is this correct?

should i change the EGR while im there?

any help would be greatly appreciated

Glenn

 

[c4c5specialist]

HI there,
Yes, it would be suggested to change that one injector. JUST MAKE SURE IT HAS THE SAME TIP DESIGN as the others.

However, the EGR is not part of the issue here, as it does NOT function during idle.

You are still batch fire injectors, so that one injector will affect the other 3 on that side of the engine.

Definately change that one injector and then reevaluate the condition.
Allthebest, c4c5

 

[Schrade]

What reading did you get on NOx's? What is the local limit?

Decrease fuel to reduce HC count. That would probably reduce CO count too, but raise burn temp, which can in turn increase NOx's. What is that read?

 

[CHERRYPICKER]

Thanks for the reply's guys...

c4c5: i think im going to change all the injectors, these might be the originals and its probably about time. As far as i can tell ( its really the first time under the hood of this car) there is no Plenum or runners to remove, just the fuel rails...is this correct?

Schrade: NO is only tested at 2000 rpm here...421 ppm limit...blew 91 ppm
: the only way that I know how to DECREASE FUEL is to take my foot off the
gas peddle.

cheers
Glenn

 

[Schrade]

Thanks for the reply's guys...

c4c5: i think im going to change all the injectors, these might be the originals and its probably about time. As far as i can tell ( its really the first time under the hood of this car) there is no Plenum or runners to remove, just the fuel rails...is this correct?

Schrade: NO is only tested at 2000 rpm here...421 ppm limit...blew 91 ppm
: the only way that I know how to DECREASE FUEL is to take my foot off the
gas peddle.

cheers
Glenn

You're at 25% of allowable NOx's. GOOD.

See some info I posted for the other emissions post here.

 

[CHERRYPICKER]

Scrade: ive read that post....it didnt seem to apply to me....have no idea what EVERCLEAR is , and we dont have any ABC stores here.
I really dont want to add anything into the gas tank as that will foul up the injectors worse than they are now....if thats where the EVERCLEAR goes...lol

gonna get 8 new injectors and see what happens.

it just seems that what ive read on here talks about taking off the Plenum and the runners before the fuel rails......i just cant see that on my 93, looks like just take off the rails, after letting off the gas pressure, and laying the rails on the winsheild, and replacing all the injectors,,,,,,,,,
is this correct?????????????????????????

thanks to all
Glenn

 

[c4c5specialist]

Your LT1 is not going to be an L98 with runners and upper plenum.
Your engine, you need to remove 4 bolts and pull the fuel rail straight up off the intake.
Lets stay with the BASICS of your failure.
TOO MUCH FUEL loading.
Like I said, you only have to replace the ONE and reevaluate.
Your choice to replace all 8.
NEVER EVER EVER add a fuel injector treatment which contains high amounts of TOLUENE, as these may short out injector windings.
Allthebest, c4c5

 

[Schrade]

Scrade: ive read that post....it didnt seem to apply to me....have no idea what EVERCLEAR is , and we dont have any ABC stores here.
I really dont want to add anything into the gas tank as that will foul up the injectors worse than they are now....if thats where the EVERCLEAR goes...lol

Everclear is pure ethanol - 95+% pure.

If you don't want to that's fine. But it IS the solution to your bad burn. Bank it.

 

[Hib Halverson]

Everclear, toluene or any other solvent based injector cleaners is not the answer because when used in concentrations high enough to truly clean injectors they also attack the other rubber and plastic parts of the fuel system. As for Everclear in particular, the fuel system on a car that old will not tolerate more than 15% ethanol. You're better to drink the stuff rather than use it in your engine.

The only pour-in injector cleaners which really work well or detergent-based cleaners, the best known of which are Lucas Fuel System Cleaner, Chevron Techron and Red Line Complete Fuel System Cleaner.

While it would have been interesting to do a fuel pressure test on this engine first, like others here, I suspect that the rich-at-idle is leaking injectors.

Good luck and report back.

 

[Schrade]

We're not talking about cleaning injectors, or the use of solvents. We're talking about reducing the hydrocarbon count in his burn, long enough to pass emissions.

Ethyl alcohol (ethanol) will reduce HC count. That's a fact.

When ethanol decomposes (combustion), you get water OH2, and CO2. That also is a fact.

Some say E85 will degrade fuel system components. Others (oil companies, of course) question this degradation. Maybe it will. NO ONE however, says a tank of gas with a bottle of ethanol in it will degrade, or break down ANY component. NO ONE.

 

[CHERRYPICKER]

Thanks for all the great info guys, it is much appreciated
New injectors ordered today, will install when they arrive and expecting neck snapping results. lol

cheers
Glenn

 

[CHERRYPICKER]

Forgot to add
For some strange reason up here in the north, if your car does not pass emissions, and the cost to fix it is estimated at MORE than $450.00, then they give you a "conditional pass" which allows you to plate the car for 2 more years. ya cant sell it, but you can plate it.
All this makes NO sense to me, but who am i to argue with the government. So the car is plated and on the road, i just dont like the rich burn all the time at idle, probably fouling up the oil as well....hence the injector swap.

thanks again
Glenn

 

[CHERRYPICKER]

Injectors are installed.
took about 2 hours, not really a hard job.
ordered the Bosch III flow matched from FIC
a little different installation: injectors into the intake first, don't re-use the clips.
First install: one was leaking because it didn't seat into the fuel rail properly. Re-seated the one and all was fine.
After getting the car to temp::Test drive was good, excellent off the start, no hesitation, faster kick down when tromped.
Will check fuel mileage and have another E-test done to see if this cured the emissions problem.

Thanks all
Glenn

 

[UNCLEBILL]

Injectors are installed.
took about 2 hours, not really a hard job.
ordered the Bosch III flow matched from FIC
a little different installation: injectors into the intake first, don't re-use the clips.
First install: one was leaking because it didn't seat into the fuel rail properly. Re-seated the one and all was fine.
After getting the car to temp::Test drive was good, excellent off the start, no hesitation, faster kick down when tromped.
Will check fuel mileage and have another E-test done to see if this cured the emissions problem.

Thanks all
Glenn

Waiting for your results...had similar situation...did the Bosch III and EGR valve and MAP sensor...got a conditional but havent gone back yet to recheck...blew over on HC and NOx at 40 kmh(28 mph).....live in Ontario.

 

[CHERRYPICKER]

UNCLEBILL: Welland eh? 10 minutes away, im in St.Catharines. could be a few days before i take it in again...i hope its blowing better now than before. I'm gonna make sure its good and hot this time, get the cats nice and toasty.

 

[UNCLEBILL]

UNCLEBILL: Welland eh? 10 minutes away, im in St.Catharines. could be a few days before i take it in again...i hope its blowing better now than before. I'm gonna make sure its good and hot this time, get the cats nice and toasty.

Just a heads up....June 28..Vette show in Port Dover...there were 235 Vettes there last year and Aug. 8 in Welland at David Chev dealership...our club(Stoney Creek Corvette Club ) is putting on both.
Bill

 

[Schrade]

Will check fuel mileage and have another E-test done to see if this cured the emissions problem.

Thanks all
Glenn

What's the word?

 

[CHERRYPICKER]

Hey Schrade..

nothing new to report, ive either been to busy or its been raining like crazy to get the car in for another air test.
thanks for the thought though...lol

will let ya know as soon as i do

cheers
Glenn