MR2ocnz 25th Turbo Preperation

[Benckj]

With boost controller turned off it will run at spring pressure unless I accelerate and then it overshoots to 18+ psi. Originally I had a 14.7 spring but installed a 12 and it became more controllable. Still couldn’t hold my target of 17.

[GDII]

Definitely sounds like a waste gate issue. Obviously you shouldn't be seeing more than waste gate pressure however how is the controller bringing it back down to 5psi? The spring would shut the gate at 12psi and that should be the lowest boost you can run at WOT.

[Benckj]

I’m not really sure why it drops so low unless by my theory, stalls the turbine flow or actuator arm is fouling on bracket. Something isn’t correct which is why using the external gate should eliminate these possibilities. Just wish the new hose arrived so I could take for test run. I’ve left myself plenty of time to sort out as long as no other surprises crop up.

[Benckj]

Made some good progress yesterday after finding a length of braided 4AN hose I had left over from initial install. Took me several hours to get new hose fitted but glad I did as the connection which failed was only holding on by a small piece of rubber inside. It would have failed at some point and caused me all sorts of grief along with possible engine- turbo damage.

Time for a warm up, bolt check and test run today. Might even get a chance to change oil and swap tyres over. Any luck I’ll be ready for Manfield trip by days end. Not terribly worried with completion of tuning adjustments as I can do while driving using my VEAL program.

[Benckj]

First run went well and holding boost now. Need to adjust EBC to get my response back and ensure protection settings are good. After viewing my data log I’m still concerned about my voltage levels after replacing voltage regulator & rectifier in alternator. Very low at idle and unstable through rev range. Not sure what to check next as grounds & other connections are fine. Might have another look at my battery to see if something strange is going on. Its quite a new high tech Exide battery but worth checking all the same.

[Benckj]

Everything is looking good now with car and getting packed up for long road trip. Haven’t had a decent test drive so will need to tune on the road. Leaving Tuesday to give myself enough time to sort out any issues and visit family & friends along the way. Happy trails ahead.

[Benckj]

Finially back after an epic journey. Had a number of ‘things’ go wrong over the course of a week but nothing that would kill the trip. Just to recap some of the issues I encountered;

1/ split WI accumulator tank
2/ partially cooked waste gate diaphragm
3/ A2W pump bearing noise
4/ on road program mods
5/ intermittent charging issues

Everything was either repaired or worked around on the road so wasn’t a big deal until the clincher. On my 1,000km return trip down the West Coast the engine suddenly died while passing a camper van following a 35km corner North of Fox Glacier. Before this point I had completed some post track programing and car had never run better. It was responding quickly, very fast and got excellent economy. All my life support monitoring showed the engine was going well.

So after an hour on the side of the road trying to figure out why engine would idle but after throttle applied it would run lean, buck and die. I hitched to town when darkness fell around 8:30pm and called the garage for recovery the next morning using Swann insurance. Unlike Charlie I had never done this before so it was a new experience.

After several hours working with a couple of ol' school mechanics we identified the issue was fuel starvation and it wasn’t the filter or pump. Once I plugged in lap top and they pinched the fuel return line to keep engine running I found out my MAP sensor was unresponsive and flat lining around 20kpa. This allowed a rough idle as I take atmospheric pressure as first reading and engine uses this as a reference. After idle the computer has no idea on what to supply fuel for.

What to do 5 hrs from home? I looked at ways to modify my program to accept the OEM sensor, reprogram my EMS to use TPS as primary reference or call the wife and get a tow home. As I had a couple of mountain passes to traverse with changing weather on the way and limited towns for help I took the safe option and called the wife for rescue response. She managed to borrow a car trailer and get the 4WD ready for the road she has only driven twice.

Home now with a list of repair work ahead of me. Still pleased with the last week and cars performance. Many of you didn’t know the dramas I was dealing with as I just dealt with the issues as required. Very pleased I didn’t blow the engine as I had hit 26psi on the track and it was only my water injection which saved my bacon.

More to come.......

[mickeyduck]

Unlike Charlie I had never done this before so it was a new experience.

Welcome to the brotherhood of the broken down...

Hey I'm so glad it didn't toast itself. But then you're too careful and wise for that to happen from what I've seen.

I hit better than 26 psi too a while back when trying to figure out the fuel system (pre rebuilding it). Oddly (and perhaps thankfully) mine over-fuelled at over-boost resulting in a miss and large back-fires.

Mine is definitely running way too rich, probably just needs the fuel pressure regulator dialled in properly while on a dyno with an air-fuel meter screwed into the exhaust. It's definitely too rich at the mo and I think that's half the reason the wastegate valve is getting eaten wherever smouldering lumps of carbon get baked onto it.... Must fix the wastegate valve then find a dyno...

Here's to the next MR2OCNZ Nationals Jim. Let's you and me get our SW's sorted right and proper for it mate. I might even manage to get some time in on twisty back roads to get the feel of an SW's handling so I have more confidence on track...

A year will whizz by about as fast as an MR2 on Manfield, methinks... Look forward to seeing you then mate!

[ClanFever]

Great write up and was good to finally meet you glad you got home safe, even with a few standard mr2 bumps in the road. I found it oddly satisfying reading a write up about your break down ordeal and making your way into an unknown town to diagnose an issue. Makes an unideal situation at least worth telling! Here's hoping you can fix it

[Benckj]

Thanks for your support guys. I’ll have a poke around a few things this weekend to see what I can come up with using a clear head. When encountering problems the Engineer in me likes to not only fix but improve the system. I have tried some new concepts with this car so a few speed bumps along the way is expected.

Maybe we could meet up again closer to my home......

[Benckj]

Well it looks like I can't get a replacement board mounted MAP sensor anymore. I gathered the datasheet and I'll tap off the PCB legs to run an external standard 3 bar sensor. This will allow me to swap it out should I have problems in the future.
Pic of existing for reference.

[Benckj]

Made some progress sourcing a few parts;
1/ bought a 1.5l stainless tank to replace accumulator.
2/ ordered a Prirus water pump for A2W.
3/ ordered new fuel filter & plugs.
4/ sourced an external GM 3bar MAP sensor and figured how to connect into my options port.
5/ ordered some vacuum hose to connect external gate upper port to boost controller. May solve intermittent issue.

Also to get car mobile I chucked in the stock ECU and drove car onto ramps. Runs fine although I’m not sure how well it would cope with the aftermarket turbo & fueling. Might take it for a burst and watch my AFR gauge.