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So I am stumped on what to do for my evap system. I have an 89 Suburban that I installed a 99 7.4 Vortec and a 4l80e. I have a EZ-TCU running the trans and it seems good to go. I use and EBL Flash with the port mod for the engine. I really like it so far. It has been fun to learn. So far things have gone well. I have not drove it yet, (other than backing it out of the garage to clean). Before I start taking it down the road I want to get the evap system installed right.
The Vortec has no ported vacuum, like the old TBI did. So I am not sure what to do. Should I modify the throttle body and add a small port just in front of the throttle blade? The EBl can’t control the Vortec’s evap solenoid. But it can use the EVAP solenoid off the Camaro system, right? Can I simply add a Camaros canister or solenoid and then attach the line that went to the ported vacuum to the Vortec manifold? Would I still install the “main” line to the PVC line, like in the original TBI? Is there a way to use the EBL’s EGR circuit to run the Vortec EVAP? I don’t use the EGR.
OK, checked out the '99 EVAP system, from what I can tell the EBL ECM can control the purge solenoid that is mounted on the engine. But not the one one the '99 canister, which isn't required for your setup anyway. It is used to either seal the canister or allow air into it during purge, which in your case want it open to air all of the time.
I don't see a need for a ported vacuum source, I'd leave the purge solenoid mounted to the intake. Measure the resistance of the solenoid coil, should be no lower then about 22 ohms. This is just to check that it won't tax the ECM driver going to it. It should also be a normally closed solenoid, can check that also as there is an option flag to select a NC or NO solenoid.
On the Vortec engine I didn't see where the PCV was tied into the CCP system any any point.
RBob
Thanks for the reply. I am amazed at your knowledge and outstanding support that you share.
I measured the coil to be at 19-to 22 ohms, depending on the meter used. It is normally closed and when opened it draws .6 amps. Would that work?
It is my observation that the solenoid will allow vacuum to be applied the the canister, allowing the canister valve to open and draw vapors from the canister. Wiring the EBL to the 99 solenoid, would allow it to control the vacuum on/off. I would then just attach the purge line to the manifold rather than the PCV line? Would that be to much vacuum? I can add it to the PCV line with out much trouble. Any thoughts?
That is getting low, I just measured one that is driven by a C3 ECM (same q-driver) and it is 24 ohms.
> allow vacuum to be applied the the canister, allowing the canister valve to open
Does this canister have a valve that also goes to intake manifold vacuum? IIRC, that is the high altitude setup. Not sure if it will work as you mentioned. Or are you referring to a valve (pancake shaped) in the purge line between the tank and canister?
Can you post a picture of where this taps into the PCV and the canister?
It may be better to get a JY car canister from a late 80's mid-90's car. Check the coil resistance and that it is a NC solenoid before purchase. Plumb the purge line to the current solenoid on the engine. Wire that solenoid to +12 IGN switched volts.
The canister has no electronic valve on it. Just the pancake valve that I think you are referring too. Just looking at things and I assume that as vacuum is applied to the pancake valve it opens, and allows vapors to be drawn in to the TBI. And it looks like I may have the lines backward. The small line which I believe is the control line, goes to the PCV and the purge line to the TBI, that it is ported vacuum.
I think that I will install the 99 solenoid and add a relay under the dash and have the EBL control it. And then just add the purge line some place in the PCV line. I think that will work. Right?
The canister has no electronic valve on it. Just the pancake valve that I think you are referring too. Just looking at things and I assume that as vacuum is applied to the pancake valve it opens, and allows vapors to be drawn in to the TBI. And it looks like I may have the lines backward. The small line which I believe is the control line, goes to the PCV and the purge line to the TBI, that it is ported vacuum.
I think that I will install the 99 solenoid and add a relay under the dash and have the EBL control it. And then just add the purge line some place in the PCV line. I think that will work. Right?
The small skinny line to the PCV provides vacuum to open the purge valve. The fat line from that valve goes to ported vacuum on the TBI unit. With high(er) vacuum the skinny line opens the purge valve, while at the same time the throttle needs to be open some to uncover the TB port (fat line).
You can do the same on the new engine, but without a ported vacuum port will need to use a solenoid. You can't use a mechanical relay as the purge solenoid is pulse width modulated (PWM). It is opened and closed at various duty cycles to control the volume of purge.
A clean way of doing this would be to get a canister with a solenoid on it. Use the ECM to run that solenoid while running the purge line to solenoid on the manifold. Run IGN+ to that solenoid so that it is on with ignition. Or use another port on the intake manifold to purge with and not use the intake solenoid.
It ould be helpful to resize the images to at most 1024 X 768. At the size they are now need to pan and scroll to view the whole image.
Thanks.
Sorry bout the photos.
I will start looking for a canister from the cars that you suggested. I will just make plate to use the area that the 99 solenoid mounted to.
So I wandered around the local self pull yard, as normal there are no 3rd Gens(a few 4th gens) in the yard. There are a lot of trucks. Do you think that I can use the solenoid from a 93 to 95 TBI? The ohms where above 30 if I remember correctly. I guess I could buy new, but is just feels better to go pull it myself.
Yes, you can use that solenoid. As long as the resistance is above 24 ohms you are good to go. You could also use that canister to clean up the engine a bit. No need for the vacuum line to the PCV hose.
Just thought that I would share what I did. I took the canister and solenoid from a 94-95 TBI truck. I mounted the solenoid to the radiator core support. I then made an aluminum plate to fit where the 99 solenoid sat. Welded a little piece of tube to it. Good to go!
Weird on the EVAP solenoid. With the 350 I setup, I simply reused the stock solenoid on the Vortec intake. Stabbed a small cap HEI in the back and it has never shown any issues.
My concern is the driver in the ECM. In the C3 series it appears that the maximum continuous current is .6 A (600 mA). With the Vortec CCP solenoid hitting that number while cold.
Along these lines GM uses two outputs in parallel to drive the TCC solenoid.
My concern is the driver in the ECM. In the C3 series it appears that the maximum continuous current is .6 A (600 mA). With the Vortec CCP solenoid hitting that number while cold.
Along these lines GM uses two outputs in parallel to drive the TCC solenoid.
RBob.
Could always add a slight amount of resistance into the circuit.
I had that thought as well. I only had a small selection of resistors here at the house to play with and the smallest one I had was to big to allow the coil to work. That is why i changed. Besides, as Rob pointed out the new canister is a cleaner set up.
09-24-2015, 02:05 PM
