Root of problems? 2 Different part #s!! - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 07-08-2009, 04:08 PM   #1
Slowest Progress Ever
Thread Starter
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default Root of problems? 2 Different part #s!!

So you may have been reading about how my car goes crazy with AFR's and idles high, well I think I may have found the problem and this might help others. I thought the high idle was caused by a vacuum leak around the injectors because my vac/ boost gauge reads correctly, but the engine runs lean. As I previously mentioned, I had put new injector "isolators" in there. These are the little black washers that slip around the injector stem, and seal the injector to the intake manifold. The Miata part number is 13-257. I remember these not fitting perfectly snug on my injectors (RX-7 460's PN-195500-2010.) I called the Mazda dealer and they looked up the Miata part number, and then I told them I swapped my Miata injectors with RX-7's and are these isolators the same? They told me "No" and gave me this part number N350-13-257. I'm like 13-257? that's the same number. The guy said it's a reference that the computer uses to identify this as the "isolator" and that the RX-7 part is different than the Miata part. I didn't really believe him so I asked the price and he said $2.75 I think, the Miata ones were $3.90. So if the price is different, than the part must be different. I am picking these up on Friday, and I'm putting these in right away. I think this may very well be the root of all my AFR craziness, at least I am crossing my fingers...
thirdgen is offline   Reply With Quote
Old 07-08-2009, 04:16 PM   #2
Senior Member
iTrader: (1)
 
Join Date: Sep 2007
Location: Trenton, NJ
Posts: 1,125
Total Cats: 0
Default

Spray some Brakleen around each of the injectors individually. If the motor does something odd, then its the injector not seating right. If it doesn't do anything then your injectors are sitting fine. The brakleen is great for identifying vacuum leaks.
ArtieParty is offline   Reply With Quote
Old 07-08-2009, 04:21 PM   #3
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

large gobs of RTV goes a long way too :P


brake cleaner (highly flammable stuff is key) works wonders to find leaks.
Braineack is offline   Reply With Quote
Old 07-08-2009, 04:44 PM   #4
Slowest Progress Ever
Thread Starter
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default

I'm pretty sure they are seated right, I'm certain it's just incorrect seals. I guess I'll find out friday when I get em and throw em in.
thirdgen is offline   Reply With Quote
Old 07-08-2009, 05:48 PM   #5
Junior Member
iTrader: (7)
 
Join Date: Aug 2006
Location: Binghamton, NY
Posts: 448
Total Cats: 1
Default

I went through that when I swapped to RX-7 injectors. I had my original isolators RTVed in place and ad to swap them out 'cause the RX-7 injectors wouldn't fit. Had to use the RX-7 ones. Same OD as ours, but the ID is larger.
--Alex
AlexO35 is offline   Reply With Quote
Old 07-08-2009, 06:19 PM   #6
Slowest Progress Ever
Thread Starter
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default

When I put the miata isolators on the RX-7 injectors, they felt sloppy like they weren't near as tight as when they were on the stock miata injectors. If this fixes the problem and my car runs great, and my AFR's run smooth, I'll take back everything bad I ever said about MS. My friend's dad is in business with Bowling and Grippo and he actually told me about MS before I even was a member of this web site. He said that your engine has to be pretty much in perfect running order for the MS to work, just like any other ECU. He told me if the engine isn't up to par, I'll never get it to run right off of the MS and this is why a lot of people claim MS and EMS-Pro to be garbage. When in retrospect, it's simply a machanical flaw, or the user themselves.
thirdgen is offline   Reply With Quote
Old 07-08-2009, 07:23 PM   #7
Senior Member
iTrader: (1)
 
Join Date: Sep 2007
Location: Trenton, NJ
Posts: 1,125
Total Cats: 0
Default

Might be a silly question, but are you running the MS in parallel or are you actually piggybacking it? Does the stock ecu control any fuel or did you totally cut that wire in order for the MS to control it?
ArtieParty is offline   Reply With Quote
Old 07-09-2009, 09:15 PM   #8
Slowest Progress Ever
Thread Starter
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default

In parallel. The stock ECU has no control over spark or fuel.
thirdgen is offline   Reply With Quote
Old 07-10-2009, 08:27 PM   #9
Slowest Progress Ever
Thread Starter
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default swapped insulators again

So I picked up my RX-7 insulators today, threw em on, started the car up, and same thing. Actually it seemed to idle a little lower, like 1300 RPM. The miata insulators had like a taper on them, while the RX-7 ones were just like fat washers with no tapers. They slipped over the pintle caps and onto the injector stems and felt like the same ID as the Miata ones, which fit loosely around the stems. When I pushed the injectors into the intake and put the rail on, the rail seemed to fit tighter like it was putting more pressure on the injectors. I attached a log and my .msq again. I drove it for like 20 minutes or more and I got 2 resets very close together. I did not have ECO correction turned on, but I did have overrun turned on. If I start the car when it's hot (heat soaked) it idles high and AFR is really lean. If I drive it awile and come to a stop sign, it'll idle high and AFR's are really rich. Possibly a Coolant-Related Air Density issue?
loaded.msq

log1.xls
thirdgen is offline   Reply With Quote
Old 07-20-2009, 09:31 PM   #10
Slowest Progress Ever
Thread Starter
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default

That little pop that happens when I turn the key on sometimes...
The other night it blew off my boost gauge line. Is it possible that this coulda blew out a seal or something worse to cause my high idle crap?
thirdgen is offline   Reply With Quote
Old 07-20-2009, 09:49 PM   #11
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,578
Total Cats: 40
Default

Quote:
Originally Posted by thirdgen View Post
If I start the car when it's hot (heat soaked) it idles high and AFR is really lean. If I drive it awile and come to a stop sign, it'll idle high and AFR's are really rich. Possibly a Coolant-Related Air Density issue?
Attachment 12600

Attachment 12601
Sounds more like a heat-soaked IAT. I moved mine out of the engine bay (read: away from the radiator's heat) and no longer get those sort of issues.
kotomile is offline   Reply With Quote
Old 07-21-2009, 08:37 AM   #12
Junior Member
 
Join Date: Sep 2008
Location: Davie, Florida
Posts: 66
Total Cats: 3
Default

Isn't the point of an IAT sender to measure the temperature of the air entering the engine? If it's moved to outside the engine bay, I would think it would give artificially low readings to the ECU.
CoralDoc is offline   Reply With Quote
Old 07-21-2009, 08:45 AM   #13
Elite Member
iTrader: (12)
 
Join Date: Aug 2006
Location: Central-ish VA
Posts: 4,449
Total Cats: 16
Default

It can be anywhere on the cold side pipe and give accurate readings. What koto is talking about is the affect that radiant heat has on the sensor after sitting when hot. The temp will be artificially hot until the motor gets running again.
neogenesis2004 is offline   Reply With Quote
Old 07-21-2009, 08:51 AM   #14
Junior Member
 
Join Date: Sep 2008
Location: Davie, Florida
Posts: 66
Total Cats: 3
Default

Got it - all of my intake tubing is inside the engine bay, so I got confused.
I mounted the IAT sensor just before the throttle body, so it isn't near the radiator. I've also noticed that it doesn't heat soak much while sitting, but that could be partly due to the tubing being plastic.
CoralDoc is offline   Reply With Quote
Old 07-21-2009, 08:55 AM   #15
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,578
Total Cats: 40
Default

I'd still consider just before the TB = near the radiator, that's where mine was. I am using Al pipes though.

Now the sensor is post intercooler inside of the wheel well and all is good (except for some AFR wackiness but that's another thread and not due to the IAT).
kotomile is offline   Reply With Quote
Old 07-21-2009, 09:27 AM   #16
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

Quote:
Originally Posted by thirdgen View Post
That little pop that happens when I turn the key on sometimes...
The other night it blew off my boost gauge line. Is it possible that this coulda blew out a seal or something worse to cause my high idle crap?

search "better spark output circuit"
Braineack is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 57 07-19-2017 05:11 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
Need For Speed (2015) Girz0r Gaming 12 03-28-2016 04:15 PM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 04:20 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:43 AM.