99 head swap backfires 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 08-25-2011, 07:08 PM   #1
Newb
Thread Starter
 
Join Date: Jan 2011
Location: Columbia SC
Posts: 26
Total Cats: 0
Default 99 head swap backfires won't start

I swapped out my warped 96 head for a 99 head. I had the 99 head taken to a machine shop and had them shave.008 off to make sure it was straight. Then put it on the car. everything went smoothly with the installation except that we had to take about a 1/4 inch off the bottom of the passenger side chain cover mounting bracket(the stamped steel one that sits behind the cam gears).

Now the car will not start. And is back firing through the intake when cranking.

I really think that it is the ignition timing but i'm not sure of a great way to verify that it is sparking at TDC of compression stroke.

Ive tried moving the cam sensor to see if it would help. and it can stop the backfire, or it can cause a flame to shoot out of the throttle body depending on where it's positioned.

The car is a 92 with 96 block, 99 head, 90-93 MSPNP.

any advice would be appreciated.
guestlive85 is offline   Reply With Quote
Old 08-25-2011, 07:15 PM   #2
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Flip the ignition wires. Sounds like you've got the 1/4 plugs connected to the 2/3 coils and vise-versa.

The relative positions of the two coils are reversed on the 1.6 engine as compared to all of 94-00 1.8s.

It actually doesn't matter which coil is which, so long as the correct path of ECU wire -> coil -> plugs is maintained.



EDIT: just noticed that this was only a head swap, not an engine swap. Are the ignition wires hooked up the same as when this was working with the '96 head?
Joe Perez is offline   Reply With Quote
Old 08-25-2011, 07:17 PM   #3
I'm a terrible person
iTrader: (19)
 
FRT_Fun's Avatar
 
Join Date: Apr 2009
Location: Arizona
Posts: 7,293
Total Cats: 180
Default

Did you install the timing belt correctly.?
FRT_Fun is offline   Reply With Quote
Old 08-25-2011, 07:25 PM   #4
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,775
Total Cats: 1,106
Default

I bet the cam gear on one of the cams is off. When crank is at tdc the front cam lobes on both cams should be pointed outwards.
shuiend is offline   Reply With Quote
Old 08-25-2011, 08:04 PM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,846
Total Cats: 1,787
Default

(zack morris's phone)

Sounds familiar doesn't it lars....
Braineack is offline   Reply With Quote
Old 08-25-2011, 08:42 PM   #6
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

I would check the cam timing.
Ben is offline   Reply With Quote
Old 08-25-2011, 09:30 PM   #7
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,236
Total Cats: 288
Default

Another vote for cam timing.
m2cupcar is offline   Reply With Quote
Old 08-25-2011, 11:07 PM   #8
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,362
Total Cats: 1,323
Default

Cam timing.
Savington is offline   Reply With Quote
Old 08-26-2011, 01:34 AM   #9
Junior Member
 
Join Date: May 2011
Location: Columbia, SC
Posts: 115
Total Cats: -1
Default

We checked it a few times. The cam timing seems spot on.
AredMiata is offline   Reply With Quote
Old 08-26-2011, 01:52 AM   #10
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 13,775
Total Cats: 1,106
Default

Quote:
Originally Posted by AredMiata View Post
We checked it a few times. The cam timing seems spot on.
How did you check it? Did you only check the belt for 19 teeth and E/I in the right place? Put it at TDC and take a picture of how the front cam lobes are pointed on both cams.
shuiend is offline   Reply With Quote
Old 08-26-2011, 03:42 AM   #11
IHI
Junior Member
 
Join Date: Oct 2009
Location: The Netherlands
Posts: 200
Total Cats: 1
Default

If you want to check ignition timing:

Disconnect the injector connectors.
Pull out the spark-plugs
Put the spark-plugs in the Spark-plug-connector and ground them to the engine block.
Now check timing with the timinglamp.

As for the cams: you can mount the cam-sprocket wrong. The wheel for the exhaust and intake are the same but they are mounted specificly for their function.
Check the manual.
IHI is offline   Reply With Quote
Old 08-26-2011, 05:11 AM   #12
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,362
Total Cats: 1,323
Default

Quote:
Originally Posted by AredMiata View Post
We checked it a few times. The cam timing seems spot on.
We all think you're lying. Photograph the cam gears with 19 teeth between the marks, photograph the cams with #1 lobes opposite facing at #1 TDC, and also confirm that #1 TDC is actually #1 TDC - don't use your balancer, use the crank pulley mark or stick a screwdriver in the #1 spark plug hole and rotate until it's at its peak.

The only other thing it could be is if you crossed the spark plug leads or the coil plugs (plugging the 1/4 coil harness into the 2/3 coil)
Savington is offline   Reply With Quote
Old 08-26-2011, 06:36 AM   #13
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

In for failed timing pics. Some one should figure out what it takes to time it to run the intake as exhaust and vise versa. I'm surprised some timing belt first timers havent stumbled upon it yet.
curly is offline   Reply With Quote
Old 08-26-2011, 09:14 AM   #14
Newb
Thread Starter
 
Join Date: Jan 2011
Location: Columbia SC
Posts: 26
Total Cats: 0
Default

Thanks for the lack of confidence fellas, lol. Seriously hope you guys are right! I will go check and take pics.
guestlive85 is offline   Reply With Quote
Old 08-26-2011, 09:17 AM   #15
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,846
Total Cats: 1,787
Default

we doubt because we care.
Braineack is offline   Reply With Quote
Old 08-26-2011, 09:24 AM   #16
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,236
Total Cats: 288
Default

Quote:
Originally Posted by AredMiata View Post
The cam timing seems spot on.
I doubt because of this. Seems?
m2cupcar is offline   Reply With Quote
Old 08-26-2011, 10:47 AM   #17
Newb
Thread Starter
 
Join Date: Jan 2011
Location: Columbia SC
Posts: 26
Total Cats: 0
Default


Crank

Cams

Cylinder # 1 Lobes
Attached Thumbnails
99 head swap backfires won't start-010.jpg   99 head swap backfires won't start-008.jpg  
guestlive85 is offline   Reply With Quote
Old 08-26-2011, 10:52 AM   #18
Newb
Thread Starter
 
Join Date: Jan 2011
Location: Columbia SC
Posts: 26
Total Cats: 0
Default

Thanks fellas, guess I decided that it would be good to line them up without reading the letter on the stamped steel plate. Yay For Miata Turbo And All Those Who Doubted! Thanks Everyone!

Last edited by guestlive85; 08-26-2011 at 11:12 AM.
guestlive85 is offline   Reply With Quote
Old 08-26-2011, 11:21 AM   #19
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,846
Total Cats: 1,787
Default

Quote:
Originally Posted by guestlive85 View Post
Crank

Cams

Well, you did it wrong as we thought. you have E lined up with I on the intake side, and I lined up with E on the exhaust side...

when you do it correctly, I and E will point veritcally and you should have 19 belt teeth between those two marks. the Cam lobes will also point away from each other.
Braineack is offline   Reply With Quote
Old 08-26-2011, 11:24 AM   #20
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Quote:
Originally Posted by guestlive85 View Post
Crank

Cams

Cylinder # 1 Lobes
Epicly wrong that...

E = Exhaust, I = Intake, both point to 12 O'Clock whan the crank points to 12.
richyvrlimited is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
Are my coils failing? viriiguy General Miata Chat 5 09-28-2015 08:39 PM
VR6 to Miata Swap ScrapinMX5 Meet and Greet 8 09-28-2015 02:04 PM


Tags
99 head, backfire, wont start

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 07:59 PM.