Removing EVAP System??

[MrZ71man]

I did a search, and I can't find any info. Is there a way to remove some of the EVAP controls of the PCM? After I did the motor swap, I couldn't take a lot of the EVAP system components on the fuel tank, and it's throwing codes and my motor is acting crazy...Please help!!

[2002_z28_six_speed]

Evap system problem ---> Vacumn leak.

[97K15004WD]

What year is your vehicle? OBDII requires different responses from the monitoring sensors, depending on the year. PCM is looking for .040 size leak in one year, .020 size leak in others, in some, doesn't care. EVAP system holds tank vent gases and if not done properly, can vaccuum your tank flat. Be aware that the solenoids allow engine vac to draw vapors into the engine after an off cycle and a certain outside temp is met. PCM goes into test mode to check for leaks by creating small vac and then times how long it takes to reach atmospheric pressure (uses MAP and pressure sensor in the tank to compare).

Thats why he said "vaccuum leak".....

[mr.prick]

What year is your vehicle? OBDII requires different responses from the monitoring sensors, depending on the year. PCM is looking for .040 size leak in one year, .020 size leak in others, in some, doesn't care. EVAP system holds tank vent gases and if not done properly, can vaccuum your tank flat. Be aware that the solenoids allow engine vac to draw vapors into the engine after an off cycle and a certain outside temp is met. PCM goes into test mode to check for leaks by creating small vac and then times how long it takes to reach atmospheric pressure (uses MAP and pressure sensor in the tank to compare).

Thats why he said "vaccuum leak".....
nice first post.

[MrZ71man]

The engine is from a 2004 Silverado, but my truck is a 1995. I kept my original fuel tank but put a new fuel pump in it (for the increased PSI). The donor truck had sensors in the gas tank to monitor the pressure and fuel level. I kept the purge canister from the tank and installed it on mine during the swap, but didn't take the other sensors. I was wondering if there is a way to delete the necessity for this system, or if I just need to swap in the whole fuel tank assembly/system?

[2002_z28_six_speed]

So is the Evap canister hooked up or not? I was thinking that maybe you have the Evap canister still on the engine and the PCM is turning it on without the evap line hooked to anything ---> big vacumn leak.

Try diabling the Evap in the PCM first:

LABELS Purge Canister Open Loop
Parameters Value
{B0501} Purge Canister Min Temp 30.000000 °C
{B0502} Purge Canister Min Speed 16.093445 KMH
{B0503} Purge Canister Min Air Flow 12.000000 Grams/Second
{B0504} Purge Canister Min Run Time 100.000000 Seconds
{B0505} Purge Canister Open Loop Disable

You shouldn't have to swap everything over unless you really want a good smelling car.

[MrZ71man]

So is the Evap canister hooked up or not? I was thinking that maybe you have the Evap canister still on the engine and the PCM is turning it on without the evap line hooked to anything ---> big vacumn leak.

Try diabling the Evap in the PCM first:

LABELS Purge Canister Open Loop
Parameters Value
{B0501} Purge Canister Min Temp 30.000000 °C
{B0502} Purge Canister Min Speed 16.093445 KMH
{B0503} Purge Canister Min Air Flow 12.000000 Grams/Second
{B0504} Purge Canister Min Run Time 100.000000 Seconds
{B0505} Purge Canister Open Loop Disable

You shouldn't have to swap everything over unless you really want a good smelling car.

I'm trying to understand this a little more...those are currently all of my stock values, but are you saying all of those need to be changed? If so, what would you recommend changing the values to?

[2002_z28_six_speed]

These conditions will not allow the purge canister to open:


LABELS Purge Canister Open Loop
Parameters Value
{B0501} Purge Canister Min Temp 139.960938 °C
{B0502} Purge Canister Min Speed 411.979618 KMH
{B0503} Purge Canister Min Air Flow 511.992000 Grams/Second
{B0504} Purge Canister Min Run Time 13421772.793750 Seconds
{B0505} Purge Canister Open Loop Disable

[97K15004WD]

nice first post.

Thanks. This is a great site, and I hope I can contribute.

[MrZ71man]

I figured that's what you meant - just set the parameters so high that there is no possible way for the requirements to be met. It seemed to work out. I'll eventually have to swap the tank assembly over, as I live in Cali and have to get this smogged in a year:bash:

[Bruce Melton]

Good info!

[2002_z28_six_speed]

Did that adjustment fix it?

[MrZ71man]

Did that adjustment fix it?

The truck is definitely running A LOT better, but isn't where it should be quite yet...but I am happy that it is finally achieving closed loop. The 02 sensors are still throwing codes every once in a while and I'm not sure why:nixweiss:

[97K15004WD]

Did you replace your rear O2 sensors? If you still have the original ones from your 95, they are 12 years old and likely the cause of your problem.

[MrZ71man]

Did you replace your rear O2 sensors? If you still have the original ones from your 95, they are 12 years old and likely the cause of your problem.

The 02 sensors are from the 04 exhaust, since there was only one 02 sensor on the 95 5.7L engine. If I continue to have problems with them, I will definitely replace them...but they shouldn't have problems after 3 years

[97K15004WD]

I can't remember for sure; but was your old O2 sensor an electrically heated one? Also, the newer O2 Sensors heat up much faster so the PCM can go into closed loop much faster, sometimes as fast as 30 seconds. How do you have them hooked up?

Which PCM are you using, the original or something different?

[MrZ71man]

I can't remember for sure; but was your old O2 sensor an electrically heated one? Also, the newer O2 Sensors heat up much faster so the PCM can go into closed loop much faster, sometimes as fast as 30 seconds. How do you have them hooked up?

Which PCM are you using, the original or something different?

I purchased a wiring harness that included the wiring for the 4 02 sensors. They make a ton of different hot rod parts and vehicle specific conversion kits: www.hotrodlane.cc

The 2004 PCM is required to run this motor. The 95 PCM is still attached, although I think I can remove it since it has no requirement for engine/transmission functions, as the new motor was also swapped in with the 04 transmission.

[WiseGuyZ06]

I just shut off the codes in the pcm... Ive never had a problem

[MrZ71man]

Well, I go to start up the truck this morning and crank, crank, crank. No fire. I've tried many times throughout the day, but I can't get it to fire. I can hear the fuel pump running when I turn the key on, so it should have fuel. Maybe no spark?

No trouble codes...does anyone have any ideas?

[97K15004WD]

What's different? Didn't it run before? Did you remove the old pcm. I'm wondering if the VATS has somehow become active, stopping spark.....

[MrZ71man]

What's different? Didn't it run before? Did you remove the old pcm. I'm wondering if the VATS has somehow become active, stopping spark.....

I drove it last night with no problems. It just won't fire completely out of the blue...:nixweiss:

I am at a total loss of ideas right now as to what it might be

[MrZ71man]

So the truck is still not firing. I pulled a plug and cranked it over and it has spark. I'm thinking that is may be the fuel pump, but I can't check the fuel pressure because I don't have a gauge handy. I replaced the fuel filter for the heck of it, but no change. Could it be the injectors?

[MrZ71man]

Well I finally hooked up the old fuel pressure gauge and got a whole 0 PSI out of the fuel pump...looks like i'm dropping the tank later this week when I get some time, now I wish I didn't have a full tank of gas :bash:

[2002_z28_six_speed]

Well I finally hooked up the old fuel pressure gauge and got a whole 0 PSI out of the fuel pump...looks like i'm dropping the tank later this week when I get some time, now I wish I didn't have a full tank of gas :bash:


Been there done that. Full tank, too.

Floor jack will be your friend on that one. 80 lbs of sloshing fuel. Yummy. :cheers:

[MrZ71man]

Been there done that. Full tank, too.

Floor jack will be your friend on that one. 80 lbs of sloshing fuel. Yummy. :cheers:

I'm away at school and don't have the luxury of a floor jack, but I will have a spare tire jack :wave:

I've decided instead to siphon out the gas, and since I have no where to store it, I will sell it to my roommates for a discount price of 2.50 a gallon (normally 3.15 around here).

:cheers:

[hquick]

Lol! Better than dumping it on the ground.
I used rope slings to drop the tank in my Burb when changing the pump.
I had 150L in it at the time!

[MrZ71man]

Well I finally got around to dropping the tank and pulling the fuel pump. Turns out the fuel pump was fine...the problem was the the rubber hose that connects the fuel pump to the hard line on the fuel pump housing had came loose, so the fuel pump was just spraying all the fuel back into the tank. I replace the hose and clamps, and the truck is back to running great!!:cheers:

[2002_z28_six_speed]

What a bother! Glad to here you are back on track.

Any other tuning issues?

[hquick]

What a pest...but glad you got it sorted out...cheaply!

[MrZ71man]

What a bother! Glad to here you are back on track.

Any other tuning issues?

No other tuning issues yet...just trying to get my e-fan tuning worked out, but I really don't know where to start:bash:

[hquick]

What's the issue with the fans?
Can you just use the stock settings as per a similar vehicle?
That's what I did..I just ended up lowering the temps a little after running the motor and checking temps.
These are my settings:

{G1203} Type Of Fans Fitted To vehicle Series Parallel Fans
{G0901} Fan #1 Turn-on Temp 93.007813 °C
{G0902} Fan #1 Turn-off Temp 91.015625 °C
{G0903} Fan #1 Turn-on By A/C Temp 0.000000 °C
{G0904} Fan #1 Turn-off Speed 48.280335 KMH
{G0905} Fan #1 Turn-on Speed 28.968201 KMH
{G0906} Fan #1 Turn-on Delay 0.250000 Seconds
{G0907} Fan #1 Turn-off Delay 0.062500 Seconds
{G0908} Fan #1 Minimum On-Time 50.000000 Seconds
{G0909} Fan #1 Run-on temp 96.015625 °C
{G0910} Fan #1 Run-on time 120.000000 Seconds
{G0911} Fan #1 A/C Pressure Enable 1482.642530 kPa
{G0912} Fan #1 A/C Pressure Disable 1310.273553 kPa
{G0913} Fan #2 Turn-on Temp 96.015625 °C
{G0914} Fan #2 Turn-off Temp 93.007813 °C
{G0915} Fan #2 Turn-on Delay 0.250000 Seconds
{G0916} Fan #2 Turn-off Delay 0.062500 Seconds
{G0917} Fan #2 Minimum On-Time 30.000000 Seconds
{G0918} Fan #2 A/C Pressure Enable 2399.699354 kPa
{G0919} Fan #2 A/C Pressure Disable 1896.058749 kPa
{G0920} Fan#1 and #2 Both Off 104.607392 KMH

[MrZ71man]

What's the issue with the fans?
Can you just use the stock settings as per a similar vehicle?
That's what I did..I just ended up lowering the temps a little after running the motor and checking temps.
These are my settings:

{G1203} Type Of Fans Fitted To vehicle Series Parallel Fans
{G0901} Fan #1 Turn-on Temp 93.007813 °C
{G0902} Fan #1 Turn-off Temp 91.015625 °C
{G0903} Fan #1 Turn-on By A/C Temp 0.000000 °C
{G0904} Fan #1 Turn-off Speed 48.280335 KMH
{G0905} Fan #1 Turn-on Speed 28.968201 KMH
{G0906} Fan #1 Turn-on Delay 0.250000 Seconds
{G0907} Fan #1 Turn-off Delay 0.062500 Seconds
{G0908} Fan #1 Minimum On-Time 50.000000 Seconds
{G0909} Fan #1 Run-on temp 96.015625 °C
{G0910} Fan #1 Run-on time 120.000000 Seconds
{G0911} Fan #1 A/C Pressure Enable 1482.642530 kPa
{G0912} Fan #1 A/C Pressure Disable 1310.273553 kPa
{G0913} Fan #2 Turn-on Temp 96.015625 °C
{G0914} Fan #2 Turn-off Temp 93.007813 °C
{G0915} Fan #2 Turn-on Delay 0.250000 Seconds
{G0916} Fan #2 Turn-off Delay 0.062500 Seconds
{G0917} Fan #2 Minimum On-Time 30.000000 Seconds
{G0918} Fan #2 A/C Pressure Enable 2399.699354 kPa
{G0919} Fan #2 A/C Pressure Disable 1896.058749 kPa
{G0920} Fan#1 and #2 Both Off 104.607392 KMH


I am looking more for how to wire them in, check out my post for info on my setup: http://forum.efilive.com/showthread.php?t=6496

THANKS for the help!!:cheers:

[joecar]

You/I understand that this is for off-road usage, right...? ;)

[hquick]

Ahhhh...is that a cryptic message Joe?

EDIT:..Ohhh.. you're talking about the evap removal not the fans.

[joecar]

Ahhhh...is that a cryptic message Joe?

EDIT:..Ohhh.. you're talking about the evap removal not the fans.Ah, thanks Howard, good catch, I added a title to my post. :cheers:

[joecar]

MrZ71man, my apologies, I added a disclaimer to the title of your post #1. :)

[MrZ71man]

MrZ71man, my apologies, I added a disclaimer to the title of your post #1. :)

Yeah, the truck is used completely off-road. Here is a pic if you are interested:

http://i7.photobucket.com/albums/y281/MrZ71man/IMG_4350.jpg

[joecar]

Yep, that looks like an offroad truck... ;)

[N0DIH]

And it even looks off (to the side of the...) road.....

[2002_z28_six_speed]

Removing that fan controller will make it a little cleaner.

If you can just make the connections exactly like TunedByGM said you should be ok. It is basically three seperate circuits switched by the relys. http://forum.efilive.com/attachment.php?attachmentid=2015&d=1187667521

Can you post up the exact model of fans you got?

[MrZ71man]

I really don't remember and the fans don't say. The controller isn't variable (so its either on at a full 29 amps or off). That's why I want the computer to control it. I got them back in the summer of 04, I think. I'm pretty sure this particular model is discontinued (I believe these are 270, and the new model would be 280)