I just had a shop put in an engine in and I am in need of some verification on the boost/vacuum lines.

I've driven the car right out of the shop as is for awhile now and today I've decided to do a boost leak test. As I am pumping air in I found air coming out of this nipple/pipe on this solenoid. Is there supposed to be something hooked up to this? (picture with one arrow)

Also please verify the shop has installed my boost lines correctly(picture with three arrows). The line to the boost pressure sensor is also connected to this line(no arrow indicated).

Any help would be appreciated. I cannot find a close up shot of this area and sorry if this is a newbie question.

 

What is your rpm at idle?

 

So the Idle after the engine install was super high at around 2K. I thought they had just adjusted the throttle cable for an proper engine burn in. Because of that I adjusted the throttle cable and was able to get around 800-900 RPM at idle.

The reason I wanted to do a boost leak test was because at full boost I can hear some kind of clicking going on.

Anyways, doing more research on this topic I "think" I may have found my answer by piecing things together. The diagrams found online are super difficult to tell which of the nipple goes where on that fuel pressure solenoid. EVOMOTO's tutorial on boost gauge install has real images that helped a lot. The nipple that is currently not connected on the fuel pressure solenoid needs to be connected to the fuel pressure regulator along with the line going to the gauge pressure sensor. The other nipple goes to directly to the intake manifold.

I hope this is correct. I now probably have to re-adjust the throttle cable.

Thanks

 

thats the fuel pressure regulator solenoid, at cold starts it cuts vacuum to to the fpr so the engine can warm up quicker with the added fuel,

take the vacuum line away and you will have all sorts of starting issues, because your intake manifold has a vacuum leak too now,

some people (including myself) remove this solenoid along with the egr solenoid, but you still need to connect the intake manifold vacuum line to the fpr, this is where I tapped for my boost gauge. Hope it helps, easy fix

 

Seems like I am back with some boost issues. The shop apparently found a way to have the car boosting at 19 psi. I found the boost/vacuum line connected incorrectly as mentioned above. Now I found my boost control solenoid is stuck open during the boost leak test(no matter if the solenoid is energize or not air passes through the nipples).

I had issues with boost previously and have another boost control solenoid on hand. Putting this tested good solenoid(allows air to pass through the nipples only when powered and solenoid clicks) on and the new vacuum connections as I described above and my car is now only boosted to max at ~10PSI . I am about done with this car. Might take it to the dealer for repair? Suggestions? I am from Sacramento, CA. Any shop around here you guys can recommend?

 

19psi is the factory boost on these cars

 

Yes I am aware of that. It is what I want but cannot seems to properly get it with the proper vacuum/boost connection and a good boost control solenoid.

Here is a summary of what was said above: The shop was able to have the car boosting at 19PSI but when I checked the vacuum/boost lines it was wrong. Also found the boost control solenoid was not working as intended. I fixed the vacuum/boost lines and replaced the boost control solenoid and now I am at 10PSI max.

 

I put back the vacuum/boost line as the shop did and still not boosting past 10-11 PSI.

I re-installed the bad boost solenoid and was able to get it to boost higher than 10 PSI but seems like its over boosting (23 or 24+ PSI).

With the bad boost control solenoid I can blow air through the nipple no matter if I apply 12V to the solenoid or not. Will something like this cause over boost if installed?

BTW my car is stock.

 

https://www.evolutionm.net/forums/ev...m-diagram.html

As you can see on the diagram there's no connection between what controls boost and the fuel pressure solenoid. But since messing with the solenoid causes a boost change you must have a connection.

Having the fuel pressure solenoid venting increases fuel pressure. Leaving it venting will cause you to run rich. My understanding of the purpose of the fuel pressure solenoid is that it vents at hot start not cold start to vent any fuel vapor in the fuel line that may have been produced by heat soak.

 

Right now I have the vacuum/boost connection hooked up correctly(Stock) according to EVOMOTO and the Manual's diagram.

My next step is to check the electrical connection of the harness for the boost control solenoid. Not sure but I am guessing the wires from this harness is straight from the ECU? I will be tapping wires from this harness to a voltmeter to see if there is a change in voltage when driving the car.

I am starting to think I have a electrical connection problem from the ECU (or whatever is sending the signal) to the the boost control solenoid.

 

Will be starting a new thread on troubleshooting the electrical connection of the boost control solenoid.

 

My fail at reading comprehension. I failed to catch your switch from discussing the fuel pressure solenoid to the boost solenoid.

 

19psi is the factory boost on these cars