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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hi guys. I'm swapping a LQ4 truck engine into my car and I'm looking at my current fuel system and had a question. I was looking at all the fuel lines and I traced this line to the front of the engine bay on the driver side opposite where the battery would go. I have no ide what it is and if I need it for my set up. If anyone could help me out that would be great. I'm pretty positive its not the return or delivery line. I think it might be the EVAP line but I have no idea what it does or if I need it. Thanks!
You need it. Along with the canister that's missing, or some reasonable substitute.
That's how air gets into the tank to replace gasoline that's taken out, and how air gets out when gasoline is put in.
Looks like you're a victim of the usual "cleaning up the engine bay" stupidity... where somebody just takes out and throws away things that are "ugly", or they don't know what they do, or they're "getting rid of all the emissions crap", or "making more room to work", or some other such ignorance.
Shouldn't be too hard to find something off of some car or other at the junkyard that will work.
The LQ4 probably had all that stuff down at the gas tank. There's a canister down there, and a vent solenoid associated with it.
You need it. Along with the canister that's missing, or some reasonable substitute.
That's how air gets into the tank to replace gasoline that's taken out, and how air gets out when gasoline is put in.
Looks like you're a victim of the usual "cleaning up the engine bay" stupidity... where somebody just takes out and throws away things that are "ugly", or they don't know what they do, or they're "getting rid of all the emissions crap", or "making more room to work", or some other such ignorance.
Shouldn't be too hard to find something off of some car or other at the junkyard that will work.
The LQ4 probably had all that stuff down at the gas tank. There's a canister down there, and a vent solenoid associated with it.
Yeah the guy I bought this car from was a major hack. A lot of sketchy things going on that I'm trying to fix up. With the charcoal canister do I need to have any other lines running anywhere or is it just that line and and everything is all good?
Yeah the guy I bought this car from was a major hack. A lot of sketchy things going on that I'm trying to fix up. With the charcoal canister do I need to have any other lines running anywhere or is it just that line and and everything is all good?
Unless your particularly fond of the smell of gasoline , like the guys have already said yes you do need the canister , and of course also a way to purge that canister so it does not become saturated with fuel . The usual mechanism of purging involves a vacuum line running to the intake system and an electrically controlled purge valve that opens under certain conditions , allowing the fuel vapors to be burned off rather than evaporating into the air (where they stink like Hell) .
Unless your particularly fond of the smell of gasoline , like the guys have already said yes you do need the canister , and of course also a way to purge that canister so it does not become saturated with fuel . The usual mechanism of purging involves a vacuum line running to the intake system and an electrically controlled purge valve that opens under certain conditions , allowing the fuel vapors to be burned off rather than evaporating into the air (where they stink like Hell) .
So thats how the are set up stock but I dont know if the LQ4 is supposed to be set up that way or if it will hurt the engine or freak out the PCM if it has that going in. Ill probably have to do more research on it
Did some quick searching and I found the LQ4 does run the EVAP into the engine. I have no idea if mine currently has the valve on the engine or the wiring for it because I bought it from someone off craigslist after hearing it run on a stand. He seemed extremely knowledgeable about the engine and all the wiring so I may ask him if he knows.
Did some quick searching and I found the LQ4 does run the EVAP into the engine. I have no idea if mine currently has the valve on the engine or the wiring for it because I bought it from someone off craigslist after hearing it run on a stand. He seemed extremely knowledgeable about the engine and all the wiring so I may ask him if he knows.
Yes , they all run the EVAP into the engine , that way the vapors that usually would have evaporated into the air are instead burned with the rest of the engine's fuel consumption . Hopefully the LQ4 's canister is still around and maybe the EVAP purge solenoid valve is mounted to it like ours is (at least on my 1989 , it's right on top of the canister) . Since your using the LQ4 's ECM it would be best to use the LQ4 's valve because that's the valve designed to work with that ECM . I have no data either way , they could be electrically identical or not , but if a third gen valve has different electrical requirements than the LQ4 valve , playing mix and match by hooking the LQ4 ECM to a third gen EVAP valve may not work .
Last edited by OrangeBird; 07-24-2019 at 09:18 AM.
Yes , they all run the EVAP into the engine , that way the vapors that usually would have evaporated into the air are instead burned with the rest of the engine's fuel consumption . Hopefully the LQ4 's canister is still around and maybe the EVAP purge solenoid valve is mounted to it like ours is (at least on my 1989 , it's right on top of the canister) . Since your using the LQ4 's ECM it would be best to use the LQ4 's valve because that's the valve designed to work with that ECM . I have no data either way , they could be electrically identical or not , but if a third gen valve has different electrical requirements than the LQ4 valve , playing mix and match by hooking the LQ4 ECM to a third gen EVAP valve may not work .
Unfortunately I dont have the engines canister and all I have of the firebird is the EVAP line. I dont think I have the vale or solenoid for it either
Unfortunately I dont have the engines canister and all I have of the firebird is the EVAP line. I dont think I have the vale or solenoid for it either
Oops , I'm sorry if I wasn't clear , the valve and solenoid are the same unit . If you don't have the canister from the LQ4 maybe a local junkyard has the same kind of truck and you can check to see exactly what's involved in an LQ4 evap and buy those parts .
Oops , I'm sorry if I wasn't clear , the valve and solenoid are the same unit . If you don't have the canister from the LQ4 maybe a local junkyard has the same kind of truck and you can check to see exactly what's involved in an LQ4 evap and buy those parts .
Oh ok. Its weird because summit racing has them listed separately but I also know nothing about all of this. Ill text the guy I bought the engine from but I believe that it was a 2005 silverado HD. And ill probably go find one at a junkyard because they are $80-$100 online
Oh ok. Its weird because summit racing has them listed separately but I also know nothing about all of this. Ill text the guy I bought the engine from but I believe that it was a 2005 silverado HD. And ill probably go find one at a junkyard because they are $80-$100 online
I can see where buying a new one would run $80 to $100 , especially if the valve is mounted to it . That's why I suggested the local "pick & pull" , you can grab the connector for the valve and anything else you may need of the EVAP system to adapt into your car .
If I may offer a suggestion , obtaining the service manual for the truck your taking the engine from would go a long way toward showing you what the engine (and ECM) need to be happy in it's new environment . Which , BTW , I've never taken a truck engine and put it in a third gen , you DID verify first that this does in fact work , fit wise , yes ? I only ask because I've read of certain truck front engine brackets (the ones for the alternator , power steering and such) being too tall (or otherwise dimensionally incorrect) to fit in a third gen .
Last edited by OrangeBird; 07-24-2019 at 11:36 AM.
I can see where buying a new one would run $80 to $100 , especially if the valve is mounted to it . That's why I suggested the local "pick & pull" , you can grab the connector for the valve and anything else you may need of the EVAP system to adapt into your car .
If I may offer a suggestion , obtaining the service manual for the truck your taking the engine from would go a long way toward showing you what the engine (and ECM) need to be happy in it's new environment . Which , BTW , I've never taken a truck engine and put it in a third gen , you DID verify first that this does in fact work , fit wise , yes ? I only ask because I've read of certain truck front engine brackets (the ones for the alternator , power steering and such) being too tall (or otherwise dimensionally incorrect) to fit in a third gen .
I know in its stock form it wont fit, the alternator is too high and I believe the intake is too. The LS 1, 6 and i think 2 intakes will fit and 2 of them need new injectors but I knew that coming in. http://www.dirtydingo.com/shop/index.php This company has a bunch of LS swap stuff and I've checked some other sources and I know what I need. Im probably just going to get everything set up without a hood for a bit so I have as many stock components as possible to make sure everything works and then change over to clear the hood.
The LQ4 engine block is exactly the same as an LS1/LS6. The difference is the intake manifold, front accessories and oil pan. If you use LS1 front accessories from a 4th gen f-body on the LQ4, everything will clear the stock k-member... or at least they did in my swap. I am using UMI solid motor mounts and LS swap mounts though. I know every company's mounts are different. The truck oil pan will not work. You need an LS1 f-body pan. I have about 1/2" - 3/4" of clearance between the back of my stock k-member and LS1 f-body oil pan. I'm pretty sure I've seen some pics from members here using the stock LQ4 intake. I don't know if they had stock or cowl hoods though.
The LQ4 AC compressor will not fit without significant work. It's down low on the right, and it requires a major chunk of the K-member to be notched out. The F body one is similar.
People use Vette accessories if they want the whole enchilada to fit... they're a better fit than the F body ones, in that one respect. Otherwise the F car ones are fine, as said above.
There are 3 basic LS accessory setups, with minor variations on each of course; truck, F, and Vette. Each of the 3 spaces the pulleys out differently. Note also that the short car intakes such as LS1 (which you wouldn't really want anyway) won't fit with the truck water pump because the upper rad hose outlet hits the TB.
The LQ4 engine block is exactly the same as an LS1/LS6. The difference is the intake manifold, front accessories and oil pan. If you use LS1 front accessories from a 4th gen f-body on the LQ4, everything will clear the stock k-member... or at least they did in my swap. I am using UMI solid motor mounts and LS swap mounts though. I know every company's mounts are different. The truck oil pan will not work. You need an LS1 f-body pan. I have about 1/2" - 3/4" of clearance between the back of my stock k-member and LS1 f-body oil pan. I'm pretty sure I've seen some pics from members here using the stock LQ4 intake. I don't know if they had stock or cowl hoods though.
I have the holley LS swap mounts and inserts, the engine is already in. I have the holley 302-2 oil pan with the 4th gen windage tray and everything checks out there.
Originally Posted by sofakingdom
The LQ4 AC compressor will not fit without significant work. It's down low on the right, and it requires a major chunk of the K-member to be notched out. The F body one is similar.
People use Vette accessories if they want the whole enchilada to fit... they're a better fit than the F body ones, in that one respect. Otherwise the F car ones are fine, as said above.
There are 3 basic LS accessory setups, with minor variations on each of course; truck, F, and Vette. Each of the 3 spaces the pulleys out differently. Note also that the short car intakes such as LS1 (which you wouldn't really want anyway) won't fit with the truck water pump because the upper rad hose outlet hits the TB.
I'm only going to run waterpump, alternator and power steering and everything but the alternator is clearing right now. I found a great deal on a LS2 intake with injectors and fuel rail (no throttle body, yes im aware its a bigger throttle body) that I might get but you guys know a lot more than me so id like your opinion. Here is the link and I attached pictures of the conversation we had. https://www.facebook.com/marketplace...8133336100341/
07-23-2019, 07:07 PM
