Silicon Prairie 818s Build

[frankc5r]

Most oem systems report 85% as maximum. In other words, the ecm will use 85% as wot. Its all relative. Not sure about steady 0% at idle end. Use ohmmeter
and check resistance of tps sensor from the slider to one side. It should be a smooth transistion. An analog meter can see jumps showing errors better.

[mrbiglar]

TPS reading error was a fluke. It went away after I reset the ECU. Shows full range now, with no glitches in the range. Outside of the slight hesitation on initial throttle, I actually don't sense any performance issues with the P1507

Fuel pressure shows as 38 psi at idle with vacuum attached

Throttle body is brand new. Out of ideas other than installing the OEM throttle body to see if issues goes away?..... Crazy.

[UnhipPopano]

What is the fuel pressure when you open up the throttle? and does the pressure follow the hesitation or the throttle?

[mrbiglar]

Pressure follows transition of throttle. Went up to 40 at ~3000 rpm

[mrbiglar]

Going to check wiring today just to confirm 5V and continuity. After that, going to put OEM throttle back in and see what happens. Only thing to go on I have left is when I did a smoke test it showed a little leak around the TPS.

[mrbiglar]

Wiring checks out good. Going to leave the P1507 until I get tuned...has to be either tune or throttle body. Thanks all for advice\help above.

As a quick aside, I hooked the original gauge cluster, and no check engine light, like on STI :-) Definitely still there as COBB sees it, but thought interesting.

Doing parts inventory and clean up today, then on to install e brake, tunnel and seats.

[mrbiglar]

Drivers seat and 5 Point Harness in. Still trying to decide how to handle cable for my ebrake solution

[mrbiglar]

Ok...so Lean Condition fixed for sure. Now, I really have trouble getting it to start. Fuel pump primes, turns over, and feel I have spark since sometimes starts.

Read a post about not keeping enough fuel going during crank. I didn't reinstall the Subaru fuel damper on the return line. Any chance this is the cause?? Read a post that said you don't need this if running an after market fuel pressure regulator.

[Bob_n_Cincy]

Ok...so Lean Condition fixed for sure. Now, I really have trouble getting it to start. Fuel pump primes, turns over, and feel I have spark since sometimes starts.

Read a post about not keeping enough fuel going during crank. I didn't reinstall the Subaru fuel damper on the return line. Any chance this is the cause?? Read a post that said you don't need this if running an after market fuel pressure regulator.

Not having the fuel damper, is not going to cause the car not to start. (triple negative)

Fuel damper not that important during start. (better)

Is it possible you don't have enough gas in the tank to keep the fuel sock covered?
A fuel pressure gauge would be great. About 43 psi during starting.

Bob

[Frank818]

It takes 4 things to crank an engine:

1- Enough cranking power to spin the crank (battery, starter)
2- Enough good (not bad) fuel (43psi at 3bar, 60psi at 4bar)
3- Enough spark in the correct firing order
4- Enough piston compression (air)

[mrbiglar]

Have not posted for awhile, so thought i would catch the build thread up. Lean Condition was corrected. See the thread below if curious what we discovered.

http://thefactoryfiveforum.com/showt...Condition-HELP

I mentioned I was still having trouble getting it to start (see last couple posts above). After working through the "normal 4's" (Frank818's list above), I was getting some weird compression numbers on 1 and 2, so decided to pull the oil pan and heads to check gaskets, etc, Found the below...

https://imgur.com/MgLJnol
https://imgur.com/3A5Q5Kc
https://imgur.com/oUwCyTP

Needless to say, I found the issue. Best guess is I overheated (given spot of damage to piston). It's possible foreign matter got in, but didn't find anything. I also had a spun bearing on 2 (hence my noise from early on in my build thread. Lesson learned here is I should have thoroughly inspected the engine when I purchased with the donor.

So....keeping a glass half full mentality, I have the opportunity to do an engine rebuild:-) Been at it for the last couple of months, and most of the way done. Decided to do some upgrades while in the process.

Short Block:
- STI hardened crank and and EJ257 crankcase
- JE Hybrid Pistons
- Manley H Tough Rods
- King XPG Bearings

Heads:
- New EJ20 Heads
- GSC Performance Valves, Springs and seals

Other
-Morosso Oil Pan and Pickup
- Oil Cooler

Oil and Water Pumps were fine after a good cleaning to get all the metal fragments out. Both were new before.

https://imgur.com/GhHOpEL
https://imgur.com/fpyfLhn
https://imgur.com/EhLFTSK
https://imgur.com/ZjigAya
https://imgur.com/XK3ZfLF
https://imgur.com/9G4uWIt
https://imgur.com/1S1Y6c2
https://imgur.com/zgxFo96
https://imgur.com/MiU0IFu

[Frank818]

Oh crap, those pistons are really dead. I'm glad I could help guide you finding the issue!

But yes, in these situations we need to be opportunist and not just replace by a standard rebuild, but improve as well! It's worth it on the long run.

[mrbiglar]

A little more work complete on the engine build. Ready to re-mount in the car, and put the top end and exhaust back on. Hope to start it up next weekend!

https://i.imgur.com/rKmRvHP.jpg
https://i.imgur.com/Ro4cu4S.jpg
https://i.imgur.com/bHiGcdQ.jpg
https://i.imgur.com/Is3P6TO.jpg

[turbomacncheese]

I received the same fuel hose. You cut that hose up and really just use the straight sections, one on the bottom to the tank and one on the top to the filler cap.

Looking good.

Skip

Thanks from over here, too!! I spent a lot of time today trying to figure this out!

[mrbiglar]

Top end finished this evening. Finished re-mounting the AWIC, and primed the system with Driven Break in Oil and Coolant. Plan to start for the first time this weekend.

https://imgur.com/yIrOaar
https://imgur.com/rGSna9A
https://imgur.com/Ww9FTGx

[mrbiglar]

Family priorities took me away from the build for awhile....

Did initial start a few weekends ago, and completed my initial two 30 min runs at 2500 rpm and then oil filter change with Driven conventional break in oil.

https://i.imgur.com/yIrOaar.jpg

…..so far so good. Sounds and runs great. It is idling a little rough...likely tune related. Compression on all 4 cylinders is 170 or better. Smoke test shows no vacuum leaks. Exhaust side smoke test was good as well. Fuel pressure right where it should be both at startup and at 3k RPM.

I did switch from the Wahlbro to the DW300…much quieter. I also switched to a Cobb Turbo, and I don’t have a hose running from BOV back to Pre Turbo. I.e. Intake is capped and BOV is Vent to Atmo.

Ready to start sealing the cabin back up, and finish the interior body work. Once I have things broken in a little farther, will head to the dyno.