Cylinder 4 wont fire.

sharkbait · August 17th, 2010, 03:26 PM

Alright.

I just swapped my 4.6 out and put the 5.4 in.

The problem im having is cylinder 4 wont fire.

Things we checked-

Spark plug
Wire
Coil
Injector
Injector signal
We checked to see it was actually sparking
I took it apart and check the gasket
No obstruction of air
Compression test
Leak down test
Vacum check
Checked the followers and the cam and both are in good condition
No smoke and its no coolants getting in there.

Any ideas?

roybrown45 · August 17th, 2010, 03:39 PM

is the gap correct on the plug?

limited · August 17th, 2010, 03:47 PM

need more info for people to get a better idea, Like what was the compression? what % of leak?, did you check for cracked runner or other sort of vaccum leak?( overall vacuum reading not good enough to rule one out) how did you check spark and injector? swapped with another cyl? plug wires in correct spot on coil? correct KV to plug? etc

bbrewer03 · August 17th, 2010, 03:54 PM

Is the injector actually getting gas? Are for sure your getting a good consistant spark? I ask the same things above, how did you determine the plug, wires, and injector was good?

sharkbait · August 17th, 2010, 03:59 PM

Compression was 170

Idk what leak down was but it was "good" on the gauge.

We pulled the plug and sat it on the motor and cranked it and spark was good.
We checked injector signal with some diodes they have for that flash when the injecot gets power
We swapped injecotrs to and from that cylinder

Vacum is 21-26hg

We swapped out the coil pack
Wire
and plug
We made sure the plug is at .56

Intakes is a brand new HPS intake
Gaskets have been re checked

limited · August 17th, 2010, 04:11 PM

got the stock manifold? if so put it on and see results. I am thinking you might have a vacuum leak at that cyl. is the miss just at idle or thru out the rpm range? does it set a p0304 code?

I never seen a Good range(which is what?) on a leakdown tester, would have been nice to know % and where the leak was going( all motors have some sort of leak)

bbrewer03 · August 17th, 2010, 04:13 PM

And fuel to the injector? I'm stumped........

Is the tune for a 7 cyclinder?

sharkbait · August 17th, 2010, 04:27 PM

Originally Posted by limited

got the stock manifold? if so put it on and see results. I am thinking you might have a vacuum leak at that cyl. is the miss just at idle or thru out the rpm range? does it set a p0304 code?

I never seen a Good range(which is what?) on a leakdown tester, would have been nice to know % and where the leak was going( all motors have some sort of leak)

Cant use the stock 5.4 intake.

Also we thought that but its an aluminum intake manifold so it cant crack and i inspected it and there wasnt an holes.

Its not really like a miss. More of a cylinder death lol. Like it wont fire at all. It dosnt fire at idle or under load.

86er · August 17th, 2010, 06:03 PM

Originally Posted by sharkbait

Cant use the stock 5.4 intake.

Also we thought that but its an aluminum intake manifold so it cant crack and i inspected it and there wasnt an holes.

Its not really like a miss. More of a cylinder death lol. Like it wont fire at all. It dosnt fire at idle or under load.

aluminum can and will crack. Have you sprayed the motor with soapy water yet?

somehow you are not getting fuel. The injectors are a ground side circuit, go back and make sure nothings wrong with the harness

mrsinister2424 · August 17th, 2010, 06:12 PM

You said you made sure it sparks right? Did you take a screw driver and put it in the ignition plug and hold it close to a ground to see if its firing? Did you test the injectors? Take the rails off the motor, with the fuel line and injectors connected, then rest the injectors in the top of a water bottle, make sure your fuel pump is on, and then turn the key to the on position, see if it pressurizes and shoots fuel out of each injector. If you have fuel, and you have spark, there is literally no reason it won't fire. If all other cylinders on that side are firing it can't be that your timing is that far off.

0949er · August 17th, 2010, 06:17 PM

yeah how sure are you that you are getting fuel? Because you are sure you are getting spark?Any of the valves stuck open?

August 17th, 2010, 03:26 PM	#1
sharkbait Hooo Ha Ha 1997 Mustang GT 11.65 @ 115 Join Date: Apr 2009 Location: Pasadena MD Posts: 9,743 iTrader: 10 reviews	Cylinder 4 wont fire. Alright. I just swapped my 4.6 out and put the 5.4 in. The problem im having is cylinder 4 wont fire. Things we checked- Spark plug Wire Coil Injector Injector signal We checked to see it was actually sparking I took it apart and check the gasket No obstruction of air Compression test Leak down test Vacum check Checked the followers and the cam and both are in good condition No smoke and its no coolants getting in there. Any ideas? __________________ 410rwhp 520rwtq @ 12.9 psi

August 17th, 2010, 03:39 PM	#2
roybrown45 Regular 2001 Mustang GT Join Date: May 2010 Location: Tullahoma, TN Posts: 495 iTrader: 0 reviews	is the gap correct on the plug? __________________ Car is for sale: http://nashville.craigslist.org/cto/2510060805.html http://www.autotrader.com/fyc/vdp.js...id=AT-121bdd21

August 17th, 2010, 03:47 PM	#3
limited Premium Member 99 limited edition vert Join Date: Mar 2007 Location: Tacoma,Washington Posts: 3,297 iTrader: 0 reviews	need more info for people to get a better idea, Like what was the compression? what % of leak?, did you check for cracked runner or other sort of vaccum leak?( overall vacuum reading not good enough to rule one out) how did you check spark and injector? swapped with another cyl? plug wires in correct spot on coil? correct KV to plug? etc __________________ KB'd 446rwhp/451rwtq, Mustang Dyno http://www.youtube.com/watch?v=3ZDpQ0EEm1M Tuned by Joe at http://www.tricktuners.com

August 17th, 2010, 03:54 PM	#4
bbrewer03 Regular 1997 Mustang GT Join Date: Aug 2006 Location: Kentucky Posts: 178 iTrader: 0 reviews	Is the injector actually getting gas? Are for sure your getting a good consistant spark? I ask the same things above, how did you determine the plug, wires, and injector was good? __________________ 1997 GT Cobra R Hood, Cobra Front bumper, MSD plug wires, Tailights, Projector headlights, 18x9 chrome bullet wheels in front and 18x10s in back, Tunable Induction Cold air intake, flowmaster mufflers. 4.10 Gears.

August 17th, 2010, 03:59 PM	#5
sharkbait Hooo Ha Ha 1997 Mustang GT 11.65 @ 115 Join Date: Apr 2009 Location: Pasadena MD Posts: 9,743 iTrader: 10 reviews	Compression was 170 Idk what leak down was but it was "good" on the gauge. We pulled the plug and sat it on the motor and cranked it and spark was good. We checked injector signal with some diodes they have for that flash when the injecot gets power We swapped injecotrs to and from that cylinder Vacum is 21-26hg We swapped out the coil pack Wire and plug We made sure the plug is at .56 Intakes is a brand new HPS intake Gaskets have been re checked __________________ 410rwhp 520rwtq @ 12.9 psi

August 17th, 2010, 04:11 PM	#6
limited Premium Member 99 limited edition vert Join Date: Mar 2007 Location: Tacoma,Washington Posts: 3,297 iTrader: 0 reviews	got the stock manifold? if so put it on and see results. I am thinking you might have a vacuum leak at that cyl. is the miss just at idle or thru out the rpm range? does it set a p0304 code? I never seen a Good range(which is what?) on a leakdown tester, would have been nice to know % and where the leak was going( all motors have some sort of leak) __________________ KB'd 446rwhp/451rwtq, Mustang Dyno http://www.youtube.com/watch?v=3ZDpQ0EEm1M Tuned by Joe at http://www.tricktuners.com Last edited by limited; August 17th, 2010 at 04:14 PM.

August 17th, 2010, 04:13 PM	#7
bbrewer03 Regular 1997 Mustang GT Join Date: Aug 2006 Location: Kentucky Posts: 178 iTrader: 0 reviews	And fuel to the injector? I'm stumped........ Is the tune for a 7 cyclinder? __________________ 1997 GT Cobra R Hood, Cobra Front bumper, MSD plug wires, Tailights, Projector headlights, 18x9 chrome bullet wheels in front and 18x10s in back, Tunable Induction Cold air intake, flowmaster mufflers. 4.10 Gears. Last edited by bbrewer03; August 17th, 2010 at 04:13 PM. Reason: SP FUEL*

August 17th, 2010, 06:12 PM	#10
mrsinister2424 Hardcore Enthusiast 99' Mustang GT 3214@OVER 9000!!! Join Date: Dec 2008 Location: Redlands, CA Posts: 2,629 iTrader: 0 reviews	You said you made sure it sparks right? Did you take a screw driver and put it in the ignition plug and hold it close to a ground to see if its firing? Did you test the injectors? Take the rails off the motor, with the fuel line and injectors connected, then rest the injectors in the top of a water bottle, make sure your fuel pump is on, and then turn the key to the on position, see if it pressurizes and shoots fuel out of each injector. If you have fuel, and you have spark, there is literally no reason it won't fire. If all other cylinders on that side are firing it can't be that your timing is that far off. __________________ 99' Rio Red Mustang GT: --My Garage-- Check garage. Vortech V-1 intercooled running 9lbs of boost Life= eat, lift, eat, eat, eat, sleep, repeat

August 17th, 2010, 06:17 PM	#11
0949er MM Fanatic 2004 Mustang GT 12.85 @ 114 Join Date: Apr 2010 Location: Charlotte Posts: 3,224 iTrader: 0 reviews	yeah how sure are you that you are getting fuel? Because you are sure you are getting spark?Any of the valves stuck open? __________________ MODS: Vortech V1 T-Trim @ 7.5 PSI (tuned down) Comp Cam Stage 2's + more 432 rwhp / 396 rwtq 02/27/2011 NEW VIDEOS! It takes ~$60 a rwhp (over stock) for a 99-04 Mustang GT. Do the Math C2H5OH on the horizon

Remove Advertisements Sponsored Links
Ford Mustang Forum Advertisement

Threads Similar to: Cylinder 4 wont fire.
Thread	Thread Starter	Forum	Replies	Last Post
help, two miss fire codes wont go away	02gtvortech	99-04	7	July 5th, 2010 02:28 PM
Cylinder 1 Miss Fire	scxc15	99-04	19	February 21st, 2009 06:14 PM
86 GT wont fire	alabamastanger	5.0 Mustangs	3	March 15th, 2008 06:17 PM
MY FORD LASER JUST STOPPED FOR NO REASON - WONT FIRE -HELP	molly	New Members Introductions	3	September 6th, 2007 10:56 AM

All times are GMT -4. The time now is 12:47 PM.
Contact Us - Modded Mustangs : Ford Mustang Forums - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.