1G Aftermarket FPR & stock FPR solenoid

[dwb]

I'm installing a FueLab 515 fuel pressure regulator in my 1g and I'm reading some conflicting information about what to do with the stock FPR solenoid. Do I keep the solenoid in-line with the vacuum/boost source or eliminate it?

Some say to leave it in-line for better startup conditions, others say to eliminate it due to potential failure. Is there a general consensus which way to go? If not, is there a better list of pros and cons? I'm running ECMLink if it matters.

 

[1990TSIAWDTALON]

Go straight from the intake manifold to the AFPR and forget about the solenoid. I have never used mine and I haven't had any issues at all.

 

[Bud92gsx]

Yes straight to intake manifold.
When I did mine, I got a end of fuel rail adapter to thr fpr. And just ran that line to intake manifold

 

[dwb]

I wanted to follow up on this thread for continuity sake. I went with the advice to bypass the FPS and daily drove it like this for several months. I discovered a few things in the process:

• I was having some issues of near-stalling when coming to a stop and some cold start-stalling issues so I decided to see how it would behave if I re-hooked up the FPS. Unfortunately it didn't seem to do anything.
• Poking around ECMLink, I discovered this:
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• A "stock" 1g ECMLink configuration has the FPS turned off by default. So when I installed ECMLink previously in a stock configuration, I (unknowingly) turned off the FPS. So bypassing the FPS didn't do anything at all.
  • I definitely noticed a difference between the stock ECU and ECMLink in regards to how it idled in some circumstances (pre-AFPR).
• "Enable normal (factory) settings" on the FPS tab of ECMLink was disabled, so I enabled it.

Catching idle at a stop no longer feels as though it will stall and I have not noticed anymore cold start stalling issues. I call that a WIN! (where's that dancing banana emoji when you need one? )

 

[evil_eagletalon]

I bandaided my starting issues related to temp by adjusting cranking fuel tables.

 

[Stapl3]

I wanted to follow up on this thread for continuity sake. I went with the advice to bypass the FPS and daily drove it like this for several months. I discovered a few things in the process:

• I was having some issues of near-stalling when coming to a stop and some cold start-stalling issues so I decided to see how it would behave if I re-hooked up the FPS. Unfortunately it didn't seem to do anything.
• Poking around ECMLink, I discovered this:
  You must be logged in to view this image or video.
• A "stock" 1g ECMLink configuration has the FPS turned off by default. So when I installed ECMLink previously in a stock configuration, I (unknowingly) turned off the FPS. So bypassing the FPS didn't do anything at all.
  • I definitely noticed a difference between the stock ECU and ECMLink in regards to how it idled in some circumstances (pre-AFPR).
• "Enable normal (factory) settings" on the FPS tab of ECMLink was disabled, so I enabled it.

Catching idle at a stop no longer feels as though it will stall and I have not noticed anymore cold start stalling issues. I call that a WIN! (where's that dancing banana emoji when you need one? )

This is great. We delete that solenoid for simplicity, as we should, but a team of engineers put it there and it's ECU controlled to do something and we ignore all of that. Pretty rad that you thought to use it as it should and put the ECU settings to do so with positive results.

My gripe with the solenoid was it wasn't barbed nipples on it and there was simply more connections. If there is a failure of your FPR getting a boost reference, your FPR isn't going up 1:1 and your shit will blow. Everyone is getting AN fittings for their valve cover yet using a rubber line from the AFPR to manifold like that is fine. And it's weird to me the factory is using rubber lines to a plastic solenoid with no barbs on it, that should all be beefed up. Amazing shit to see really.

It would be interesting to play with the values, meaning check the box above instead, and see how the engine behaves.

 

[dwb]

My gripe with the solenoid was it wasn't barbed nipples on it and there was simply more connections. If there is a failure of your FPR getting a boost reference, your FPR isn't going up 1:1 and your shit will blow. Everyone is getting AN fittings for their valve cover yet using a rubber line from the AFPR to manifold like that is fine. And it's weird to me the factory is using rubber lines to a plastic solenoid with no barbs on it, that should all be beefed up. Amazing shit to see really.

It would be interesting to play with the values, meaning check the box above instead, and see how the engine behaves.

I agree regarding the plastic and non-barbed nipples on the FPS. But to that point, a lot of the OEM vacuum line connectors and splitters didn't have barbs and were plastic, same with the EGR solenoid. Not quite as critical as the FPR boost source, but the engineers still thought it was sufficient. Granted they were only running a little more than 10psi boost.

The other settings on the FPS tab in ECMLink are for aftermarket systems. "Such systems include nitrous oxide systems and water or alcohol injection systems."

 

[1990TSIAWDTALON]

If you have issues with the car trying to die when you come to a stop, look at your coasting offset value in link. I think most set it to 100 or 200 and leave it alone. Just pointing that out is all.

 

[Stapl3]

I agree regarding the plastic and non-barbed nipples on the FPS. But to that point, a lot of the OEM vacuum line connectors and splitters didn't have barbs and were plastic, same with the EGR solenoid. Not quite as critical as the FPR boost source, but the engineers still thought it was sufficient. Granted they were only running a little more than 10psi boost.

The other settings on the FPS tab in ECMLink are for aftermarket systems. "Such systems include nitrous oxide systems and water or alcohol injection systems."

I was suggesting to tweak the values a little from stock to see what happens.

But yeah you're just controlling when the solenoid clicks over then you can use that to a relay then the world is your oyster. I use it to activate the secondary tables. I use those to have different timing during cold start, so pretty much the opposite as intended use. I love being able to switch to the other tables and wish there were many more to use. It's one of my favorite features in Link.