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-   -   Issues - Help? (https://www.miataturbo.net/diy-turbo-discussion-14/issues-help-31443/)

Newbsauce 02-12-2009 09:21 AM

Issues - Help?
 
2 Attachment(s)
So.. the car has been pretty much been parked since my dyno/tuning day (2 months of real sitting though). It's been started and run once in awhile, but the important thing to know is that nothing on the .MSQ has changed.

Anyway here's the scenario:

I gave it an oil change, and decided to drive it this week. The car is stumbling hard into boost and misfiring. Pulled the plugs, changed them. Pulled some MS logs, but it does not appear to be a tuning issue, as my map was just tuned.

Here's what's noticeable:
1> The car starts and idles fine with perfect AFR, will run fine through a normal out of boost 1st gear pull.

2> The biggest change: The car seems to go crazy lean when I punch it (transition to boost), but runs fine under normal load (out of boost). It also seems to be a bit leaner across the board in general, but specifically in boost. (13.1 when it was 11.8-12ish during tuning)

3> The RPM pickup is going a bit nuts (log attached), but can't tell if that is recent.

Some things to know:
1> The fuel filter and pump were changed at the same time (about a year and a half ago)

Setup:
1.6
MSq
550s (rx7)
gt2871
Toyota COPS
Walbro 190.

I'm pretty much open to anything at this point... fire away.

m2cupcar 02-12-2009 09:31 AM


Originally Posted by Newbsauce (Post 367422)
...will run fine through a normal out of boost 1st gear pull....

As in a full rpm range out of boost run to see if it's boost related or rpm related?

Newbsauce 02-12-2009 09:34 AM

yes....not sure if I logged it but I was able to pull 1-6.5k in first with no bogging/hesitation.

m2cupcar 02-12-2009 09:41 AM

I had the same problem with a misfire under boost. It would run fine up the rpm band w/o boost. Swapped out the newish no-name autozone wires for some used NGK blues and it solved the problem. Maybe the similar problem with RPM issues might indicate something in the ignition - like the cops or wiring. :dunno: There are loads of toyotas/lexus that use those cops. You could swap out a know good one for each cylinder. That's how I found a bad cop on my RX300.

Newbsauce 02-12-2009 09:48 AM

1 Attachment(s)

Originally Posted by m2cupcar (Post 367434)
I had the same problem with a misfire under boost. It would run fine up the rpm band w/o boost. Swapped out the newish no-name autozone wires for some used NGK blues and it solved the problem. Maybe the similar problem with RPM issues might indicate something in the ignition - like the cops or wiring. :dunno: There are loads of toyotas/lexus that use those cops. You could swap out a know good one for each cylinder. That's how I found a bad cop on my RX300.

What has me confused is this:

This is a log from my dyno day....
Look at the RPM vs RPM100 on this versus the log I took yesterday.

y8s 02-12-2009 10:45 AM

what's that you say about water getting into your hood and corroding your spark plug??

Newbsauce 02-12-2009 10:51 AM

That was pre-dyno day had a coolant bursting issue, as well as the rain issue... should not really be a factor here. Either way, here's the picture of the plugs ;) 1-4 from left to right. Cyl 3 ftw.

http://i40.tinypic.com/689coj.jpg

m2cupcar 02-12-2009 11:20 AM

can u post up a screen cap of the above logs? can't look at 'em right now.

Saml01 02-12-2009 11:32 AM

Fuel pump maybe?
COP's are fried?
Update the resistor on the spark mod, maybe that will help.

Newbsauce 02-12-2009 11:37 AM


Originally Posted by m2cupcar (Post 367474)
can u post up a screen cap of the above logs? can't look at 'em right now.

No software here on the work computer :(


Originally Posted by Saml01 (Post 367482)
Fuel pump maybe?
COP's are fried?
Update the resistor on the spark mod, maybe that will help.

Well the pump is fairly new.. can't be more then a year and a half or so and is just as loud as ever (Walbro 190hp). Would the car idle as well as it is with bad cops?

y8s 02-12-2009 12:06 PM

1 Attachment(s)
datalog updated for AFR.

Newbsauce 02-12-2009 12:20 PM

Wideband is AEM UEGO. Should be "non-linear" I believe. As for TPS.. nope.

y8s 02-12-2009 12:40 PM


Originally Posted by Newbsauce (Post 367506)
Wideband is AEM UEGO. Should be "non-linear" I believe. As for TPS.. nope.

fixed afr--aem linear. it was showing down into the 9:1 range with non-linear for AFR holmes.

Braineack 02-12-2009 12:46 PM

I best I can think of is: Bad gas from sitting, boost leak, bad coils, or bad injector.

Saml01 02-12-2009 01:48 PM


Originally Posted by Newbsauce (Post 367485)

Well the pump is fairly new.. can't be more then a year and a half or so and is just as loud as ever (Walbro 190hp). Would the car idle as well as it is with bad cops?

Mine idled well with bad cops but would cause the MS to reset and the car to die momentarily as soon as I get into boost. So thats a possibility, but why would they just die all of the sudden. What Dwell are you running?

Vashthestampede 02-12-2009 02:20 PM


Originally Posted by Newbsauce (Post 367462)
That was pre-dyno day had a coolant bursting issue, as well as the rain issue... should not really be a factor here. Either way, here's the picture of the plugs ;) 1-4 from left to right. Cyl 3 ftw.

http://i40.tinypic.com/689coj.jpg

lol.....think again. Any chance you have the FM hood? Thats why I sold mine. Water resting on the valve cover soaking the plugs and wires, corroding the contacts. I had similar issues and changed to regular NGK wires with new plugs, that solved my misfire. Then once I replaced my fuel pump I was back in business.

Vash-

Newbsauce 02-12-2009 02:22 PM


Originally Posted by Vashthestampede (Post 367562)
lol.....think again. Any chance you have the FM hood? Thats why I sold mine. Water resting on the valve cover soaking the plugs and wires, corroding the contacts. I had similar issues and changed to regular NGK wires with new plugs, that solved my misfire. Then once I replaced my fuel pump I was back in business.

Vash-

Worse.. Erebuni hood. Have it sealed to prevent leaks. The majority of the water came when my thermo failed to open and it burst every single little hose in the coolant system :) Flooded the valley. Either way, the plugs I'm posting are the ones I ran on the dyno (247 rhwp). They have since been changed to spanking new BKR7E -11.


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