Notices
DIY Turbo Discussion greddy on a 1.8? homebrew kit?

HELP. misfire? running rough

Thread Tools
 
Search this Thread
 
Old Oct 6, 2010 | 09:30 PM
  #1  
Miazda318's Avatar
Thread Starter
Newb
 
Joined: Nov 2006
Posts: 29
Total Cats: 0
From: Bossier City, LA
Default HELP. misfire? running rough

i have a 1990. with a sr t25. stock everything else.
ive had the set up on for about 3 months. stock ecu. havent got on my car past half throttle. retarded ignition timing some.

today, at lunch, it randomly started idling like it was a misfire. it still has the power its had. and not lag.
when i drive it, still has the rough sound, it sounds like an exhaust leak. so i replaced the the manifold gasket, and turbo gasket.
i smell a slight hint of oil. but its not constant.
i changed plug, wires, and ran a compression check (1-175psi. 2-140psi. 3-172psi. 4-170psi.)

im irritated with it....need some help.
Old Oct 6, 2010 | 10:03 PM
  #2  
Miazda318's Avatar
Thread Starter
Newb
 
Joined: Nov 2006
Posts: 29
Total Cats: 0
From: Bossier City, LA
Default

...and its not throwing any codes.
Old Oct 6, 2010 | 11:15 PM
  #3  
lordrigamus's Avatar
Senior Member
iTrader: (14)
 
Joined: Aug 2008
Posts: 1,482
Total Cats: 0
From: Tinley Park, IL
Default

How much boost were you running? Intercooled or not? That number 2 compression reading is screwed up. They shouldn't vary that much.

Did you pop the head gasket or crack a piston maybe?

Need a little more info on the setup.
Old Oct 6, 2010 | 11:24 PM
  #4  
Miazda318's Avatar
Thread Starter
Newb
 
Joined: Nov 2006
Posts: 29
Total Cats: 0
From: Bossier City, LA
Default

im running 7psi. non intercooled. basically slapped it on. ive been babying it the setup was put on.

im not sure if the headgasket is blown, no water in oil.
with out taking the head off, how do i check the piston. besides a scope.
Old Oct 6, 2010 | 11:32 PM
  #5  
lordrigamus's Avatar
Senior Member
iTrader: (14)
 
Joined: Aug 2008
Posts: 1,482
Total Cats: 0
From: Tinley Park, IL
Default

A leak down test might be able to pinpoint the cause of compression loss. To be honest, I'm not sure, I've never had to do one. Something is definitely amiss in your number 2 though.

You may have popped the headgasket and that could be the noise you're hearing.

I'm sure someone more knowledgeable in the leak down procedure will chime in or you can Google it.
Old Oct 6, 2010 | 11:36 PM
  #6  
lordrigamus's Avatar
Senior Member
iTrader: (14)
 
Joined: Aug 2008
Posts: 1,482
Total Cats: 0
From: Tinley Park, IL
Default

What did the spark plug look like when you pulled it? Was it wet? Was the inside of the cylinder wet?
Old Oct 6, 2010 | 11:43 PM
  #7  
Miazda318's Avatar
Thread Starter
Newb
 
Joined: Nov 2006
Posts: 29
Total Cats: 0
From: Bossier City, LA
Default

the spark plugs and cylinders were dry. the plugs had the look of being ran hot, and rich.

i'll research the leak down procedure.
Old Oct 6, 2010 | 11:46 PM
  #8  
lordrigamus's Avatar
Senior Member
iTrader: (14)
 
Joined: Aug 2008
Posts: 1,482
Total Cats: 0
From: Tinley Park, IL
Default

Let me get this straight you are running the stock ecu, stock injectors with no fuel supplementation and no intercooler at 7 psi?

I don't know if that's such a good idea. You might have messed something up.

Were the plugs white? I bet your running lean not rich. In boost anyway.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
Apr 12, 2021 04:21 PM
Frank_and_Beans
Supercharger Discussion
13
Sep 12, 2016 08:17 PM
90 Turbo
MEGAsquirt
19
Oct 19, 2015 03:23 PM
The Gleas
MEGAsquirt
3
Oct 1, 2015 09:30 AM
shooterschmidty
Engine Performance
8
Sep 30, 2015 10:28 PM




All times are GMT -4. The time now is 03:04 AM.