FD2BLK

I'm Done your fix IMHO is a half assed solution and you will smell the problem some day.

kopbet89c4

So.... what *could* happen? As in smelling the problem, does that mean my gas tank will implode or explode? Will the purge canister imlode or explode? Will my car leak gas through either the canister or tank? I am so confused. I dont think there are any of these systems on a hot rodded swapped pre-emissions vehicle...

BTW, It is not like I am gutting the cats and/or removing them. I'm just removing this EVAP canister just because I see it cured my problem. Again, I emphazise that I don't see this stupid thing even on a 1960s vehicle retrofitted with a TPI/SEFI system. Do those vehicles suddenly have "smelly gas" problems if they have such an important item deleted?

MikeC4

here's what is going to happen...

on a long drive, gas vapor fumes will accumulate under you hood, creating an environment not unlike that which occurs in your cylinders. Your hot exhaust manifold will eventually ignite the AFR which you have created, at which time an explosion will occur, blowing your hood some 50 feet into the air.

kopbet89c4

I have just completed a long drive from Tampa to Daytona Beach , + lots of city and highway driving and have not even smelled a whiff of gas fumes yet from under the hood. There is still a lot of gas left in my tank too. Took th gas cap off and the "whooshing" noise has been as always since day one of owning my Vette.

I also took some of the hoses off the canister to see if I can smell gas at all. I don't seem to smell any. Since I am using a vented gas cap already called "VentLoc" I assume the gas vapors are eventually vented into the air.

Like I said before, I dont see hot rodded TPI/SEFI retrofitted pre-emissions vehicles with their hood exploding. They don't look like they have vacuum lines as complex as my TPI MAF controlled C4. Seems ok to eliminate them + the EGR which has also cause me locks of hair. Geez... I just think its something regarding to emissions control. 60s cars with retrofitted FI systems don't even have EVAP canisters or EGR and they seem fine. What, is it like the Feds are gonna be after me and check under the hood for an EVAP can, EGR control once I finally remove the AIR system??? Sorry if I'm gonna be offending someone if I plan to relocate my cats as well and put on some LT headers...

kopbet89c4

Let me just re-route the end hose to the air outside the hood while I'm at it...

kopbet89c4

Let me guess, if I did this right, my idle is 650-700 rpms and also the same in park or neutral or D also with the A/C on. If there are gas fumes in the engine bay, can't I just re-route the loose hose outside the the hood and put a breather on the hose at the TB?

cv67

The General put it there for a reason.

Why post your problem if your'e not going to listen to these guys? Your'e going to do what you want anyway, why waste their time?

kopbet89c4

What, for emissions? I have already talked vis'a'vis to 3 people about this and to 3 other people (CF members) on the phone. Sounds like their cumulative "brain power" led me to think that this is just something to do with emissions regardless of driveability. Sorry if this is what you other CF members think but I'd also like to give feedback on what I think the problem is.

Another alternate solution is to remove Alvin's piggyback tune and put the stock 22# injectors, replace the vacuum line to the canister and then the chip should be 100% factory original, except for the fact I still will have my SuperRam. I might have to unblock the EGR though to prevent a code 32. Might cost me a few buck but some of you think that I have visual/emissions tests in my county. And Bogus, I still do have my main cat.

CFI-EFI

You aren't even close. I hope a little if this gets through, but I have my doubts. For most of us, the fact that you've defeated a piece of smog equipment, is the least of the concerns, at least of those that have been expressed. For me, it is the nature of the repair(?). To fix a faulty idle, you created a vacuum leak? That is a fine diagnostic step, but you take what that tells you and let it lead you to the repair. It isn't the fix, in itself. Many competent people spend lots of time chasing and fixing vacuum leaks. No one in their right mind creates one.

FYI. The vapor canister was there on my 1970 GS455 Stage 1, with no fuel injection. I don't know when it was introduced, but it's been around for many years on both carbureted and injected cars. It is one of the smog devices that has a ZERO effect on drivability or performance. Your engine doesn't idle better because you have removed a pesky smog device, it runs better because you couldn't figure out the proper way to straighten out the air/fuel mixture, like it belongs. You stumbled and bumbled, and voilà, it finally ran decent. You just weren't smart enough to realize that you hadn't found the cure, or to reason what it might really be.


Another head in the sand, "I don't know what the heck I'm doing." reaction.

RACE ON!!!

CFI-EFI

You aren't even close. I hope a little if this gets through, but I have my doubts. For most of us, the fact that you've defeated a piece of smog equipment, is the least of the concerns, at least of those that have been expressed. For me, it is the nature of the repair(?). To fix a faulty idle, you created a vacuum leak? That is a fine diagnostic step, but you take what that tells you and let it lead you to the repair. It isn't the fix, in itself. Many competent people spend lots of time chasing and fixing vacuum leaks. No one in their right mind creates one.

FYI. The vapor canister was there on my 1970 GS455 Stage 1, with no fuel injection. I don't know when it was introduced, but it's been around for many years on both carbureted and injected cars. It is one of the smog devices that has a ZERO effect on drivability or performance. Your engine doesn't idle better because you have removed a pesky smog device, it runs better because you couldn't figure out the proper way to straighten out the air/fuel mixture, like it belongs. You stumbled and bumbled, and voilà, it finally ran decent. You just weren't smart enough to realize that you hadn't found the cure, or to reason what it might really be.


Another head in the sand, "I don't know what the heck I'm doing." reaction.

RACE ON!!!

19corvette91

now i truly have seen it all

kopbet89c4

Here is something interesting...

I plugged the hose back to where it belongs or where it belonged originally and took off one screw cap on the back of the plenum. The vacuum access hole where the screw cap belongs is physically the same size as the hole on the TB. After doing that, the car idle roughly and was sounding like it was about to stall out. Forget about leaving it that way so I put the plug back on.

Everything was back originally how it was 1-2-3 weeks ago ever since my last tune. Cranked it again. It started up, then the rpms dipped and the car stalled out again. So I disconnected the vacuum hose of the TB and put on my breather again. Cranked it up and it idled perfectly with no "hunt for idle. The best this about this was is that the idle is where it is supposed to be at 600-700 rpms; last but not least, it is as stable as a line. So far, this is my "controlled vacuum leak" much of like what my IAC is supposed to do but has never controlled the idle as well as this "vacuum leak" mod. It would make sense to connect that hose from the TB to the "traffic cone" air bridge I made recently in order for the MAF to get even more accurate readings. This is much like the "drilling holes in the TB plates" mod that many other CF member have once asked about.

Maybe my pcmforless.com tune isn't as perfect as I have once perceived it to be. Sorry Alvin, but I might have to send back the piggyback chip to make sure you did everything right in order to use the EVAP canister like the General wanted originally. Or is it perhaps using 22# factoy flow injectors from Bosch? TIA

cv67

Your'e kidding. You want to put a hole in a traffic cone, plug your line in there , assume you fixed it and blame it on the tune?

kopbet89c4

Whatever, you're always trying my patience!! WTF stop trying to be an ******* and please get back on topic. So how the heck would that not be ok? It is exactly the same as the "drilling holes in the TB plates mod" so there are no "vacuum" leaks after the air passes through the MAF. I might be getting a code 33 due to "more than 45 GM/sec air below 2000 rpms."

So far /w the breather in place of that "stupid line leading to the EVAP canister," I haven't stalled shortly after a warm start up ever since I did this. The idle is very stable @ 600-700 rpms and is recommended. It does sound a lot better than a stupidly surging idle + occasionally stalling out at a traffic light when it is humid out. That ***t is so embarrassing.

So WTF would the answer be? I think I'm just either going to:

a. Send the chip back along with current datalog for a retune using the Bosch/Ford blue top 24# injectors I have on currently.

b. Send the chip back along with current datalog for a retune using the Bosch/Ford pink top 22# injectors installed.

c. Forget the chip, remove it and if possible get a refund. Using stock 22# injectors installed, unblock EGR, plug back EVAP canister line where it originally was, use the 100% factory APYZ eprom checksum, reuse the SRI intake, base and plenum and call it a day.

The decision lies amongst thou...

cv67

I'm just quoting what you posted, how you take it from there is your deal. Its like this: Find out what the real problem is and fix it right rather than hacking it. One of those "don't use a band-aid when it needs stitches things". However, it seems like you have the answers anyway

bigcityvette

do you have the egr hole under the plenum lid sealed with the superram? if not you car will run and idle bad.

Aggravated4life

Heres my thought...prob a bit long...

When I had my 86,the evaporative system failed.The metal purge line under the car was clogged up with rust and the cannister was very old and failing.I installed a new metal line under the car and new cannister and hoses up front/back at the tank and it fixed a problem I was having.

The problem I had was excessive tank pressure and strange driveability idle problems.In the summer time,while the metal line was clogged,the tank would get so pressurized the whooshing noise would blast out and almost make the cap shoot off my hands.The gas tank was extremely hot to the touch.I went under the car to check it and im so lucky it didnt explode or implode!I nearly burned my hand touching the tank!

Im willing to bet with your system hooked up,the cannister/hoses may be leaking and youre taking constant air/fumes into the engine intake making it run badly and possibly has vacuum leaks at the hoses where the cannister purge system is set up.

When I replaced all my bad parts,I barely got a whoosh from the tank anymore and the fuel odor was gone from the back.Before I did the fix,I did try and venting gas cap but it did not help the problem much.I drove around with the back window up with the hatch tool you can buy to let the hatch stay open to allow cool air to come in and I smelled the fumes when driving,especially on hot days at a stop light.

Also,you MUST have a scanner to see if the IAC is doing its job or not.
I used my scanner to see what it was doing and the counts and it helped me to see what things I changed caused good or bad idle.

For exmaple...my IAC would count down to 5...then go to 0 in afew minutes.That is a sign of a vacuum leak/false air or incorrectly minimum idle speed adjustment.It should be 5-45 at idle or so.

A scanner is a important tool to see if youre running correctly.See,if your iac is off and getting false air,the ecm will compensate for the mixture and even if it makes your car feel like its running better,you may be getting too much fuel due to what it thinks is a lean condition.
Maybe its a fix for you because you had a vacuum leak all along and this was a band aid approach by the ecm to compensate for it.

You can possibly do away with the evap system and use a vented gas cap but use caution during the summer time when it hits 90-100 outside.The whole point of the system with that type of tank is to purge the vapors out,yes for emissions but to also keep the tank from getting too hot and pressurized!

You would also have to block off the T fitting on top of the gas tank to the left of the gas filler neck if you want to do away with the evap system.That will keep any fumes from traveling up to the engine bayif you decide to by-pass it.I just dont know if the tank will be ok with a vented gas cap alone during the hot summer months.It didnt work much on my Vette.

hippy

Why don't you just drill some small holes in the T/B blades? Maybe your IAC just needs to be reset AGAIN? Maybe your TPS voltage needs to be raised above 1v. at idle?

P.S. Kid, you didn't solve sht, you just masked your problem.

USAsOnlyWay

Ok, its late and I haven't read over all the thread.

But here is something to try. If Bill is on to something. It may be that you are sucking in gas into your intake and causing your problems. Try this.

1)Unplug the vacuum hose you have and note how the car idles. (Obviously you have done this, and it appears to idle just fine)

2)Take the now "vacuum leak" you created and plug that port on the tb. Not with the original vacuum line. But just with a plug. My thinking is this, with this port plugged. The charcoal canister system is completely cut off from the system. Also you are no longer relying on an un-metered air supply to keep the motor running. Unforunately I am without my manuals so I am unsure on how the charcoal canister system works. But I will assume my logic is mostly correct here.

Now, if it still idles like crap. I would put the charcoal canister test on hold and dismantle your TB. (Actually it would be better if you could use a code reader to see what the IAC is doing(or even working), but barring that....) Pull it apart and remove the IAC valve (Carefully) clean the entire thing out until it is clean. My thinking is, HYPOTHETICALLY saying that you have a working IAC valve. (Which may not be the case) You may have it so gunked up in side the TB that the IAC valve is not able to meter the correct amount of air in to allow the engine to idle. Then reset the TPS/IAC valve using the proper procedure explained in the Tech Tips. I urge you to do this. And do it right!

If the motor did idle fine. Then continue on testing Bill's hypothesis and see if it is indeed drawing fumes into your plenum.

Let us know how this goes and we can try to move forward on this problem.


On other thing. Don't go drilling or anything like that. You don't need that. The system should run fine without it. Hell you are on a stock cam aren't you. Just don't do anything permanant till you knocked out the easy stuff.

Also a few other questions:
1) Did it have this problem pre-SR install?
2) Did it have this problem immediatly after SR install?
3) What parts were reused on SR install? (TB/IAC valve???)

AGENT 86

Have you tried increasing the min. idle setting(and resetting the TPS). The more the min idle is increased the less work the IAC has to do. Maybe that will cure your wandering idle.
Have you diagnosed the evap system ?
Read these................................... .......................................
http://members.shaw.ca/agent86/Evapo...l%20System.pdf
http://members.shaw.ca/agent86/IAC%20Diagnosis.pdf