Welcome Darkryd

[Scoobum]

Mike is from Ottawa Ontario...and has a few issues with his car. Steve and the boys will sort it out.

[Steve Wood]

Hell...you are the go to guy around here!

Don't let him fool you, Mike!  Brad knows his stuff

[Scoobum]

I'll need some help on this one.

[darkryd]

Hi everyone.  As Scooby (can I call you Brad?) said, I'm from Ottawa (Barrhaven). Scooby thanks for inviting me to the club. My 87 GN, the "darkryd" has been in the family since it was bought in 87.  Never seen the winter. I took it over from my brother in 2011 who took it over from my Dad in 2001. 


I've been exercising a hesitation demon. Scooby Doo has been generous to provide advice/direction.  Where I'm at now is swapping in known good parts.  Starting with MAF and ECM.  Also replacing the O2 with a Denso.  Powerlogger files are posted on turbobuick.com .  parts are being shipped from a few members of turbobuick from the US. [size=78%]http://turbobuick.com/threads/hesitation-stumble-at-various-throttle-positions.443100/page-2#post-3690547[/size]


Looking forward to learning and contribute where I can.


Cheers,
Mike

[Scoobum]

Steve...have a look at the thread...and download the PL files. MAF is spikey. Anything that it would correlate with?

[Steve Wood]

did he load the files....what was it?  wheel spin that used to make spikes on launch?

[darkryd]

Hey Steve - the thread referred to is here: http://turbobuick.com/threads/hesitation-stumble-at-various-throttle-positions.443100/


let me know if you'd like me to post files here as well.

[Steve Wood]

What maf are you running?  Factory or Translator? And what chip  Not knowing what I should set the chip/maf selection toin PL makes it hard for me to know what numbers I am really looking at

the car is adding a lot of fuel at idle, then the maf spikes, the injector pulses go way up, the blm looks more normal at that time....then it comes down a sample or two later, and goes way back.

No matter what maf it is, what happens when you tap on it with the handle of a screw driver?  I am guessing either the maf is flaky or there is a bad electrical connection that is causing all these spikes to the various parameters

[Scoobum]

Steve...it's a KB chip...stock MAF.

[darkryd]

Factory MAF. I've heard of the LT1 MAF and translator.  I'll likely evolve to that in the future once this is resolved.  I have two Known Good MAFs ordered from some good guys on tubobuicks.  Coming from the US. I also have a Known Good ECM coming soon.


The chip is old.  Kenne-Bell KB9007PR chip.


As you say in your vortexbuick site, "what changed" before the issue happened.  I took the car to a garage to have an exhaust leak inspected.  The exhaust leak was sealed at the manifold and turbo.  The turbo was removed to fix the seal. Then the hesitation started.  So... something may have been knocked or broken during that work.  Since it looks like something electrical, I asked the garage to look at the grounds as well (as pointed out on vortexbuicks site).  Update on that is pending.


The garage removed the MAF but the symptoms persisted. 


I also asked them to perform the Trouble Code 45 procedure to see if it leads to a bad ECM.


We are ordering the Denso O2 as well.  We recently installed the NGK O2 but everyone says Denso is the way to go.


The only other thing that I can think of is I replaced the fuel tank and pump last year.  Its a Holley 12-900.  After it was installed in 2015 I had some fuel leaks but they were fixed.  Too much pressure on the old lines.  Then this year when we started investigating the hesitation, the garage checked the fuel pressure and it was at 80 psi. A new fuel pressure regulator was installed and that resolved that problem... <edit> resolved the problem related to the high fuel pressure.

[Steve Wood]

As I said, tap on the maf and see if anything changes.

Check the ground cable going to the turbo support cable and see if it is tightly connected with the bolt to the bracket/engine.


For a stock maf, I would wonder why the maf is reading 23 at idle instead of the correct 4-6.  I am guessing that that is why the blms are so low.  And when the maf spikes, then the injector pulses should up as one would expect and the blms go to a more normal reading.  Also, it pulls timing out of the ecm just like it thinks the pedal has been mashed even tho the tps has not changed.

And go ahead and do yourself a favor.  Order a modern TT chip.  I think I finally threw my bag of KB chips away.  The high timing they used blew many a hg and they were really crude by today's standards

[larrym]

Check the wiring to the MAF I had to repin my connector wire looked intact but was broken. 

[Steve Wood]

Check the wiring to the MAF I had to repin my connector wire looked intact but was broken.

that sounds like the best idea! 

[motorhead]

Mike,

I have a bunch of OEM parts I'd bought for my Buick (demod) before I (luckily) sold it this Spring; you are welcome to borrow/buy what you need.  I am not overly free these days what with getting ready for Drag Week - but, I am sure I can offer you some help/guidance.  I will shoot you a PM with my number/address.

Cheers,

Michael

[darkryd]

Hey Michael - its great to meet you.  Glad that you're local.  Currently the GN is at Wicked Garage out in Greely.  They've been doing the work.  I don't think its driveable though. 


Anyways, i'll call you either later today or tomorrow to discuss further. 



Cheers,
Mike