Dropping boost in mid climb last season.

[Tuesday]

Pulled things apart tonight.

Coils looked fine and did resistance test on primary and secondary and all tested within tolerance. Will try a different set though.

Fuel regulator. I have one of the orginal kits from mcx and things are plumbed a bit goofy. I need to move things around right now its routed.

Tank--filter---pump-----regulator---2 lines to to take fuel to rails and 1 return line to tank.

So basically the fuel system has 2 dead ends at rails. I will see if I can get a fitting put on end of rail and run a proper fuel loop. This set however has always worked but regardless I will put in a new fuel regulator and possible move some lines around.

Exhaust leak. Header and bellow look decent but my connecting pipe from turbo to muffler was hanging on by a thread. So this does not give me my current issue but something I need to fix.

Boys from sask that do mcx installs sent me a new muffler need to get in contact with them again to see if they have that connecting piece from turbo to muffler lying around. I think that was robertson yamaha??

Plan to check continuity along coil wires as well. Hopefully this shotgun approach will fix the problem. I know its nice to make 1 change at a time but its such a pain to tear everything down, things are not very accessible.


Will button this up hopefully on sunday and give it a test run.

 

[Tuesday]

Checked old coils all within spec. Put new coils in.

Bought a new fuel regulator from NM but have to do a bit of fuel line rerouting as I have one of the first kits and things where plumbed slightly different. Need a couple brass fittings but nothing was open this weekend. Everyone had plastic fittings.

Pulled the turbo and header. Things looked fine through exhaust system. Did some beefing up on header.

Cody from roberts yamaha will hopefully be sending the pipe from turbo to muffler next week.

Had some fun removing header and the other pipe....manage to break 3 of the 7 bolts. Had antisieze on them everytime I put them back on but this time they finally gave up. Had to tig weld end to get enough heat on them to get the bastards out. At least 2.5-3 hrs to wrestle the bolts out.

Looked through every wire I could find, all looked good.

Checked continuity on coil wires from ecu to coil plug in and jiggled the hell out of it.....everything looked good.

So I need a couple of parts before I can start testing again. Have a new af sensor and datalogger is finally talking to my computer (thanks to T-Bird).

After this if its still acting up must be a wire deep within wiring harness or my mcx ecu is failing. I really dont think its the ecu as everything worked fine on dyno, we did a number of runs and put a decent load on the motor.

Work in progress............

 

[Duke]

Coils can still be culpret. ?

 

[Tuesday]

Coils can still be culpret. ?

Roger that, put new coils on

 

[smwizzz]

Hmmm

Interesting problem. The elusive ghost that evades all.... I hate it when that happens. It is usually a simple thing once you find it. Trouble is finding it.

I had a boost problem and found the waste gate actuator had a leak. You can do a leak down test yourself. I have a Mac tool to preasure items like this up with a one way valve. You will need to have a guage on the preasure side. I do not recall the preasure used to test it. Mine was obvious... keep pumping and you had a bit of preasure.

NM's idea on the fuel preasure reg is a good one to follow up on also. If you have spark and fuel it should run especially if it did in the past. What has changed? Did you do any upgrades? I always look at the last things I did because unless you are all gummed up with varnish from sitting a long time, realistically it should still work the same.

Good luck...

 

[Tuesday]

Regulator and coils in, just waiting on exhaust piece then I can do some testing.

 

[Tuesday]

Put in the exhaust piece (thanks cody) tonight. Will do some testing tomorrow.

 

[Tuesday]

Went for a 2 hour test run today. Seems to be pulling very strong and no dropping out. Light was very flat and foggy so hard to give a full extended load test. So far looks optimistic though.

Put some local miles on this weekend and see how it holds up.

Always forget how strong a boosted sled pulls.........what a rush.

 

[Climbmax]

Bet it was the Regulator It takes fuel to make them strong
Cheers
RS

 

[Tuesday]

Bet it was the Regulator It takes fuel to make them strong
Cheers
RS

I agree, I always had the feeling that it was not getting fuel when it was sputtering.

Couple years ago I had a plugged up fuel filter and it acted very similar to this. Unfortunately this time it was not the filter.

Tired to taking it apart and putting it back together but eventually I will pull the tank off again and try my old coils and see if the problem comes back.

Thanks for the input CM.

 

[Tuesday]

2 tanks of fuel not 1 boggle so far....touch wood