pontious

Just finished removing my emission junk. ACV, EGR, Smog pump, Rats nest. Rerouted fuel lines (since the hard lines are gone now.

1) NOW I have 2 questions. On the secondary fuel rail there is a nipple that used to hook into the rats nest, it is close to where the fuel line connects. Does this just receive a vacuum cap? (Plus what is it for??)

2) On the drivers side, there is some device (I have not figure out what it is). Has a air hose connection to the Dynamic Chamber, and a T off to the bac and the air pipe that comes around from behind. It also has a (i htink 3 prong connector. I can't for life life of me figure out what it is. In fact there is some sort of metal plug in on of the air hoses so I can't figure what it is even connected up for. I can send a picture if I am beign too vague.


Any help with either or both questiosn is much appreciated.

NZConvertible

No offence, but these are the things you're supposed to know before you even start. A bit of prior research helps avoid expensive mistakes.

The fuel pressure regulator on the secondary fuel rail must be connected to a vac source, or the engine will run like crap due to excessive fuel pressure. Do not cap it!

I think the other thing you're describing is the AWS solenoid valve (causes the 3000rpm start), which can be removed and capped.

Are you reading the FSM while doing this? All the answers are in there. You should not be attemping this without the FSM to guide you.

RylAssassin

You should have kept it simple and just removed the airpump, ACV, and catalytic converter. Those are the main emissions parts.
Why did you reroute the fuel lines?

pontious

Non taken.

I did not see a clear description in the write ups I have read. And looking in the FSM all I could see/remember was that vac line going to one of the hard lines. So the forum was my next place to look.

So, a good question would be where in the FSM is this information? I must be looking in the worng places.

Thanks for your help NZConvertible.

pontious

In removing all the hard line you lose 2 metal lines that carry fuel. replacing them is thus a must

The reason I removed it all was becasue I want a cleaner engine to work on/look at. If you are removing the ACV and air pump then the rest is just sittign there doign nothing, so I removed it

hugues

I can only concur with NZ ... If you understand what you're doing, things will be much easier on you. The s4 FSM is cryptic at times so, it's not a bad idea to also read the s5 FSM since it is a little more reader/troubleshooter friendly.

For the FPR:

http://www.geocities.com/huguesdc1/fuel.html

You may want to peruse the rest of my page. I think there's some good info on it if you don't always understand what the FSM is saying (you would not be the only one).

For general how stuff works on cars, I strongly recommend the 'technical articles' in:

www.autoshop101.com

it's toyota stuff but it's good.

Hugues -

pontious

So, looking at the FSM again, I see that what I am talking about is a Fuel Pressure Regulator right? Looking at my tats nest it looks liek it origionally hooked into the EGR solenoid valve. (Well the 2nd solenoid starting from the left). You say I need to hook this into a vac source. I assume one of the three nipples on the dynamic chamber will work ok then?

pontious

I think if everyone understood the inner workings of their car there would be no need for the forum at all. I have done *most* of my homework and I am just to the point where I have questions.

I do appreciate the link (huges) , it does seem to be helpful.

hugues

What follows is the "stock" vacuum/fuel diagram ...

http://www.geocities.com/huguesdc1/faqvacuum.html

The fuel pressure regulator solenoid valve get its vacuum signal from a nipple under the BAC valve ... You can bypass the solenoid by connecting you FPR to that nipple ... I would assume any other nipple that sees vacuum is good too.

Hugues -

pontious

Shoot after reading the section on the FPR I am at even more of a lose. Since I have removed the emmisions equiq. the the pressure regulator control solenoid valve (not the EGR solenoid valve as I described earlier) is gone.

So, my understanding of what the FPR does is clearer, but myunderstanding of why I just hook it to a vac. source is a little fuzzy (as mentionded before I assuem that any of the nipples on the front of th dynamic chamber will work here for a source).

pontious

Ahh, yes, I see now. It is SO much better colorized. So, I have that nipple behind the BAC capped off and I am using a nipple in the front of the dynamic chamber as my vac source.

BTW your website is VERY helpful. I will have to go through the rest of it later. thanks for the help.

hugues

The FPR solenoid is there for "hot start" ... Under hot start, the FPR will allow for max fuel pressure for 90s ... Some pple shoose to remove the solenoid and connect the FPR to a vacuum source directly ... It's all fine and dandy maybe except for hot starts (but I don't see pple complaining about that after they removed their FPR solenoid).

Maybe NZ has more insight on this matter

Hugues-

NZConvertible

That's about right. The FPR normally alters fuel pressure to keep it the same "height" above manifold pressure, but by opening the solenoid in the vac line the FPR sees atmospheric pressure (like it would at WOT) so the fuel pressure is increased. This is only done if both the intake and coolant temps are high (i.e. hot start); meaning heat soak in the fuel rails is likely. This heat soak can cause hard starting and rough idling due to fuel vapour in the rails, so by increasing the fuel pressure the vapour is purged and the rails cooled. At the same time the ASV is opened to increase idle speed.

If you want to retain this function, you can remove the solenoid from the rack and plumb it back in with rubber lines.

pontious

Thanks NZ. So far I have not had a problem with hot starts (or otherwise) . Knowing I can put it back in if I have problems later on is a plus though...