My continuing misfire issue's, I think I figured it out...BUT

[Paps]

Updates man!

 

[bjtheman1]

Updates man!

Well, we are getting crappy weather here in the north texas right now so I haven't been able to drive and datalog for Justin.

I did just get my Camshaft Sensors in yesterday and I installed them, but without being able to do some driving not sure if anything has been changed.

 

[Eel Mit]

Ordered some new injectors, really hoping this solves my issues. I went ahead up upgraded from 38lb to 47lb injectors. Hope to get them anyway now.

When did this start? Out of the blue? or did the problem slowly develop?

I would hold off on the injectors, because they will require a retune. If the car has an issue that is not the current tune, then you will be unable to get it tuned anyway.

With a poorly running engine and lack of codes, I would suggest you look for AC (alternating current) causing the gremlins. Test the alternator. Bad diodes can wreak all sorts of havoc. I've seen it first hand.


If cam sensors are an issue, you can see that on a scope (signal drops out randomly) , but the PCM is smart enough to spot that (either CMP or CKP sesnors) and store a code. I hate to see you throw parts at an open pit, it gets expensive.

Good luck.

Tim @ Maximum Velocity

 

[Redfire_WNL]

I had very similar issue and I changed everything from the spark plugs, fuel filter, coils and checked vac leaks but the one thing that 100% fixed the issue was the injectors. Good Luck

 

[bjtheman1]

When did this start? Out of the blue? or did the problem slowly develop?

I would hold off on the injectors, because they will require a retune. If the car has an issue that is not the current tune, then you will be unable to get it tuned anyway.

With a poorly running engine and lack of codes, I would suggest you look for AC (alternating current) causing the gremlins. Test the alternator. Bad diodes can wreak all sorts of havoc. I've seen it first hand.


If cam sensors are an issue, you can see that on a scope (signal drops out randomly) , but the PCM is smart enough to spot that (either CMP or CKP sesnors) and store a code. I hate to see you throw parts at an open pit, it gets expensive.

Good luck.

Tim @ Maximum Velocity

I recieved the injectors already but I'm holding off on them until I can get those catalogs sent to Justin.

To be honest it's really hard to determine when this problem started. I had a battery/alternator/voltage issue that starting back in Sept. 2012, after so much crap finally got it fixed in April 2013. I had my car dynod last October and that's when I started to notice these issues more due to the lack of power.

I've tested the the battery and alternator multiple times, only thing I haven't checked is the alternator diodes. This is a PA performance alternator that I bought last March along with a new battery.

 

[eighty6gt]

Watching the forums for ages it's Ford alternators only. Mine went, in went a ford alt. My battery is getting a bit long in the tooth - new Ford battery.

 

[bjtheman1]

Still losing this battle.

Just the other day I put my car back to stock since I still have my stock pulley & cai. Still had the rough idle, etc.

I'll be taking it to a Ford Service Dept here soon, I'm just beaten from all this crap.

 

[AutoXRacer]

I recieved the injectors already but I'm holding off on them until I can get those catalogs sent to Justin.

To be honest it's really hard to determine when this problem started. I had a battery/alternator/voltage issue that starting back in Sept. 2012, after so much crap finally got it fixed in April 2013. I had my car dynod last October and that's when I started to notice these issues more due to the lack of power.

I've tested the the battery and alternator multiple times, only thing I haven't checked is the alternator diodes. This is a PA performance alternator that I bought last March along with a new battery.

I've had horrible experience with PA alternators...you know they are cheap Chinese units (from what I was told).

There is only one alternator I now use and its the Performance Distributors!! Its a tank!!

 

[Paps]

Did you replace injectors?

 

[RetroGT2006]

Man, I hope it gets taken care of.. I'm curious to hear what it is causing you all these problems.

 

[bumo]

Im having the same problem

 

[bumo]

I have an 08 Mustang GT with a Whipple 2.3L at 8psi.

I had a rough idle, random misfires, and significant power loss, i checked it out with a local shop and it came back clean but cylinder 5 was low on power so we preformed a compression test and it came out pretty much perfect. I changed all the spark plugs with HT0 gapped at 0.32 and the problem was still there so i replaced Coil #5 and the problem didnt go away. My tuner was adamant that the cats were clogged so i had them removed, he was right, they were absolutely toasted and would barely flow anything but the problem did not go away.

Now hes suggesting the next few steps in this order assuming the problem doesnt go away:

• 1. replace all the coils
  2. get the injectors cleaned,
  3. replace the gt500 fuel pumps,
  4. replace the fuel hat,

Does anyone agree with this? I hate having to just throw money onto a problem especially when we cant pinpoint what the actual problem is!

Any advice would be great...

 

[skwerl]

I had the same issue on cylinder #5 and began messing with the wiring harness. While inspecting the injector plug the little clip broke off in my hand. I ended up having to use a zip tie to hold the plug tight on the injector. After that the miss pretty much went away and I haven't had any misfiring since. We also checked continuity on the wire running from the coil back to the computer and it checked out fine.

 

[AutoXRacer]

I doubt this would cause all your issues, but how old is your fuel filter?
You mentioned replacing a bunch of parts, but no a word on the fuel filter.

 

[bjtheman1]

I have an 08 Mustang GT with a Whipple 2.3L at 8psi.

I had a rough idle, random misfires, and significant power loss, i checked it out with a local shop and it came back clean but cylinder 5 was low on power so we preformed a compression test and it came out pretty much perfect. I changed all the spark plugs with HT0 gapped at 0.32 and the problem was still there so i replaced Coil #5 and the problem didnt go away. My tuner was adamant that the cats were clogged so i had them removed, he was right, they were absolutely toasted and would barely flow anything but the problem did not go away.

Now hes suggesting the next few steps in this order assuming the problem doesnt go away:

• 1. replace all the coils
  2. get the injectors cleaned,
  3. replace the gt500 fuel pumps,
  4. replace the fuel hat,

Does anyone agree with this? I hate having to just throw money onto a problem especially when we cant pinpoint what the actual problem is!

Any advice would be great...

I feel ya man, this is the worst. Have you checked the 02 sensors?

 

[bumo]

While inspecting the injector plug the little clip broke off in my hand. I ended up having to use a zip tie to hold the plug tight on the injector.

This might actually be an issue... the harness is insanely difficult to clip in... i really have to push hard for it to clip into place.

I doubt this would cause all your issues, but how old is your fuel filter?
You mentioned replacing a bunch of parts, but no a word on the fuel filter.

I think its about 15000 miles old or 2 years?

I feel ya man, this is the worst. Have you checked the 02 sensors?

I preformed a full computer diagnostics test at a local shop and everything came back clean except the power loss at cylinder #5.

I think my next steps should be getting a new fuel filter and cleaning the injectors before anything else. I'm considering changing spark plug #5 before doing anything else to at least make sure that the plug is not the culprit.

 

[skwerl]

bumo, just swap plug #5 with plug #1. If the misfire follows the plug then you have your answer.

 

[bumo]

bumo, just swap plug #5 with plug #1. If the misfire follows the plug then you have your answer.

Thanks! I'll try that first

 

[bjtheman1]

This might actually be an issue... the harness is insanely difficult to clip in... i really have to push hard for it to clip into place.



I think its about 15000 miles old or 2 years?



I preformed a full computer diagnostics test at a local shop and everything came back clean except the power loss at cylinder #5.

I think my next steps should be getting a new fuel filter and cleaning the injectors before anything else. I'm considering changing spark plug #5 before doing anything else to at least make sure that the plug is not the culprit.

Good luck man, I finally bit the bullet and have an appt with Ford tomorrow morning. Love my car but if I can't get this shit fixed I'm trading it in!

 

[bjtheman1]

I guess I'm crazy b/c Ford found nothing wrong. I had them smoke test and diagnostic test everything and also had to get my yearly inspection done.

Might as well install those new 47lb injectors I've still got and get a new dyno tune. Also, going to get the Aeroforce Interceptor A/F Sensor Kit.