ECUs and Tuning Discuss Engine Management, Tuning, & Programming
Sponsored by:
Sponsored by:

Need help, won't rev

 
Old 01-08-2018, 01:52 PM
  #1  
Newb
Thread Starter
 
Join Date: Jan 2018
Location: 10-9-Oh!
Posts: 17
Total Cats: 1
Default Need help, won't rev

Hello, all.
First off, I'm not new to turbos, wrenching, or tuning. I have an issue with my miata that has me scratching my head, though.
The car is a '90 that had been sitting for a number of years and basically fell in my lap. After draining the fuel, changing the oil, and replacing the dry-rotted tires, she ran great... for a couple of weeks. Then it started limiting itself to approx. 2200rpm once fully warmed up.
I checked the AFM and TPS signals. The TPS seemed fine and the AFM seems a little off through the door's range of travel. So I replace it with a used unit from ebay. The problem remained. So I bit the bullet and ordered a replacement TPS from rockauto. Getting that bugger adjusted was a PITA, but I was finally able to. And the problem remained. The carpet was damp from the top leaking, so I pulled it up and checked the ECU. There was no corrosion present on the connector (or the TPS and AFM connectors, either), but there was just a bit on the board itself, where the connector is soldered to it. So I cleaned that off with rubbing alcohol. The problem remains.
Where do I go from here? I don't want to keep throwing money at it, but I do want it to run properly before I megasquirt it.
It does give a code for the O2s. Does anyone know if that would set an artificial redline in the ECU?
Thanks in advance for any help.

TL: DR car won't rev past 2200rpm, replaced AFM and TPS. What next?
smote is offline  
Old 01-08-2018, 02:20 PM
  #2  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,267
Total Cats: 201
Default

Megasquirt that thing and tune from there. Especially if you are already having ecu problems.


i have lots of spart 1.6 parts too if you need anything.
matrussell122 is offline  
Old 01-08-2018, 02:39 PM
  #3  
Senior Member
 
Join Date: May 2007
Location: Atlanta
Posts: 656
Total Cats: 104
Default

Fuel pressure? I'd pull the pump and look for varnish. I snagged a truck that had sat, did your basics and fuel filter, ran great for a few weeks. Then wouldn't rev. Yada yada, tank was corroded and clogged my new filter. Had to drop the tank and get it cleaned and sealed, been a great truck since.
gooflophaze is offline  
Old 01-08-2018, 03:02 PM
  #4  
Newb
Thread Starter
 
Join Date: Jan 2018
Location: 10-9-Oh!
Posts: 17
Total Cats: 1
Default

Originally Posted by gooflophaze View Post
Fuel pressure? I'd pull the pump and look for varnish. I snagged a truck that had sat, did your basics and fuel filter, ran great for a few weeks. Then wouldn't rev. Yada yada, tank was corroded and clogged my new filter. Had to drop the tank and get it cleaned and sealed, been a great truck since.
That had occurred to me, and I need to do those things as well. But the fact that it runs great until fully warmed up leads me to believe it's ECU related. It doesn't act like its starving for fuel or low(er than normal) on power. It just hits a hard 2200rpm redline.
smote is offline  
Old 01-08-2018, 03:28 PM
  #5  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,267
Total Cats: 201
Default

When i got my 90 miata it sat for 3 years and all i did was dump 5 gallons of fresh premium in and called it a day. It sounds like an electrical issue causing a limp mode to enable. And really a Megasquirt would be able to solve any ecu issue since you are the one setting all the limp mode safety features.
matrussell122 is offline  
Old 01-08-2018, 03:29 PM
  #6  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,267
Total Cats: 201
Default

i might have a spare 1.6 stock ecu if you want to try it one day. I work in Kent and at the Snoqualimie fire station a few days a month
matrussell122 is offline  
Old 01-08-2018, 06:51 PM
  #7  
Newb
Thread Starter
 
Join Date: Jan 2018
Location: 10-9-Oh!
Posts: 17
Total Cats: 1
Default

Originally Posted by matrussell122 View Post
i might have a spare 1.6 stock ecu if you want to try it one day. I work in Kent and at the Snoqualimie fire station a few days a month
I might take you up on that offer. I live in Tenino, but my parents are in the Fairwood area and I get out there sometimes. The car is not my daily, so I'm not in a huge rush to get it fixed. In fact, I might just skip it and do the MS.
smote is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
10100111001
General Miata Chat
0
08-02-2016 08:08 PM
vtluu
Hydra
12
06-15-2010 01:23 AM
linuxbox
General Miata Chat
1
10-25-2009 03:50 PM
UrbanSoot
MEGAsquirt
4
01-31-2008 05:03 PM
Mach929
MEGAsquirt
3
05-28-2007 09:07 AM


Thread Tools
Search this Thread
Quick Reply: Need help, won't rev


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.