1.8-t ran yesterday and today won't start - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 11-04-2011, 11:39 PM   #1
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default 1.8-t ran yesterday and today won't start

I started my car for the first time yesterday since a recent rebuild. I replaced the pistons and rings, honed the cylinders, and decked the head. Yesterday it was running, though not idling, and revving crappy below 2500rpm, above that and when cruising it was fine. So I assumed it was just that the rings needed to seat. Today I went to start it and it would crank and crank and it I gave it any gas it would backfire extremely loudly. any ideas on where to start with this?

mods are 95 block, weisco pistons, eagle rods, arp hardware, 99 head, ms pnp, gt2871 turbo, 550cc injectors.
Zapp is offline   Reply With Quote
Old 11-04-2011, 11:55 PM   #2
Junior Member
 
Join Date: May 2011
Location: Columbia, SC
Posts: 115
Total Cats: -1
Default

Check timing. Take off valve cover and take pictures of your cam gears when they are in line.
AredMiata is offline   Reply With Quote
Old 11-05-2011, 12:09 AM   #3
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

Quote:
Originally Posted by AredMiata View Post
Check timing. Take off valve cover and take pictures of your cam gears when they are in line.
ok I will do that tomorrow evening when I get off work.
Zapp is offline   Reply With Quote
Old 11-07-2011, 10:34 AM   #4
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

After running several tests I have concluded that the timing is good, compression is 170 across the board, both coils are good, the cas is good, and all 4 injectors are working. Is it possible that this is a problem with the megasquirt or the tune?
Zapp is offline   Reply With Quote
Old 11-07-2011, 11:00 AM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

it's getting too much fuel....why? what did you change?
Braineack is offline   Reply With Quote
Old 11-07-2011, 12:43 PM   #6
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
it's getting too much fuel....why? what did you change?
I don't think I changed anything that would cause it to get too much fuel.
Zapp is offline   Reply With Quote
Old 11-07-2011, 12:52 PM   #7
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

and you're certain of your cam timing?
Braineack is offline   Reply With Quote
Old 11-07-2011, 01:18 PM   #8
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

Here are some pictures...

Intake cam lobes with cyl one at tdc


Exhaust cam lobes with cyl one at tdc


intake cam gear


exhaust cam gear


crank pully


There are 19 teeth on the timing belt between the notch on the intake cam and the notch on the exhaust cam.

As you might notice the crank pully isnt reading that it is at tdc, which confused me because I used the screwdriver in the spark plug hole method to find tdc, so it's perfectly at tdc if I'm not mistaken.
Attached Thumbnails
1.8-t ran yesterday and today won't start-2011-11-07_12-06-32_2.jpg   1.8-t ran yesterday and today won't start-2011-11-07_12-06-27_264.jpg   1.8-t ran yesterday and today won't start-2011-11-07_12-07-26_499.jpg   1.8-t ran yesterday and today won't start-2011-11-07_12-07-19_971.jpg   1.8-t ran yesterday and today won't start-2011-11-07_12-07-43_381.jpg  

Zapp is offline   Reply With Quote
Old 11-08-2011, 09:43 AM   #9
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

Does anyone have any ideas on what I can try or test to get this thing going again?
Zapp is offline   Reply With Quote
Old 11-08-2011, 04:35 PM   #10
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

Also I just remembered that I replaced the plugs with ones that were 2 stages colder. From a bkr5e to a bkr7e. I wasn't sure of this could be a problem. But im grasping for ideas
Zapp is offline   Reply With Quote
Old 11-09-2011, 07:32 PM   #11
Junior Member
 
Join Date: Mar 2011
Location: Guildford, UK
Posts: 164
Total Cats: 0
Default

Could your valve timing be out?

If you've skimmed the head then you might need to use verniers to correct the timing.
Freaky Roadster is offline   Reply With Quote
Old 11-10-2011, 09:33 AM   #12
Newb
Thread Starter
iTrader: (1)
 
Join Date: Sep 2011
Posts: 25
Total Cats: 0
Default

Thanks everyone one for the ideas. The cam timing was a little off, but it still was able to run with it like that. The problem was that my tune went bad on ms, I reflashed the firmware and reburned the tune and it fired right up. Then I just had to change the timing a little bit and now it runs like a champ!
Zapp 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
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 08:31 AM.