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Intermittent Power Loss

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JakeSixx

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Discussion starter · #1 · (Edited)
Hey all,

It's been a while. Been pretty busy with life and training. But anyway, been having an issue as of late.

SYMPTOMS:
-Intermittent power loss. Can not figure out when or how to cause it, it just happens. It almost feels like a switch is saying 'Okay, full power' or 'Nah, just some right now.'
-Check Fuel Cap light is also intermittent but not always connected. However, it usually does come on right after a hard acceleration.
-No codes.

TESTS:
-Scanned via Torque and could not find anything. Fuel trim seemed normal, O2 checked out. Again, no codes, and double checked with Autozone.
-Going to go for a drive and bypass the purge valve to check that out.

SUSPECTED?
-Purge valve sticking
-Fuel system...Somewhere...Filter was replaced roughly 20k ago.
-Possible filter/MAF sensor? Haven't cleaned it since I got it.

MODS THAT MAY BE IMPORTANT:
-Tune
-Cold Air
-Flowmasters


Please let me know what you guys think. Been talking with my dad who is a huge ford guy and couldn't wrap his head around the fuel cap with no code. Really don't want to worry about this right now -.-


Different issue: Torque only registers 93% throttle when I have the peddle on the floor. Normal or no?
 
#3 ·
Fuel cap light???

I don't remember my 99 gt having a check fuel cap light..
 
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Discussion starter · #4 ·
New fuel cap, sorry forgot to mention! And no, I don't smell any gas. Engine sounds normal. It seems to be pretty well normal with the PVC disconnected from the system, and it's now idling like my tune told it to.

Freaks, I heard 99/00 had it as an option, but I'm not to sure on that.
 
#5 ·
Nice!! I've had 2 99 gt's and none of both came with that option :(
 
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#6 ·
how many miles does the car have? My buddies having the same kinda issues with his car, only when its warm tho. It's a possibility if your car has a lot of miles one or more of your coil on plugs are starting to go. How has your MPG been latley? My buddy has a 98gt but we're suspecting its a ignition problem, so it might be the same story on your car.
 
#7 ·
Funny you say look back on my last post, it was about this exact same thing... Never figured it out EXACTLY WHAT YOUR TALKING ABOUT, I unplugged my maf check connections hooked it back up and it hasn't happen since, however it had never done it until I out my aem pump in, whether that's related idk but I'm waiting for it to start hapening again lol best of luck to you
 
Discussion starter · #8 ·
Only running about 92k right now so low miles, and did a pretty extensive check and replace when we got it at 72k. I already have replaced one of the COPs, and it does not feel like there is any miss...Maybe one of the cylinders just aren't fully firing? But that would make it more of a rough run?

Trick, I'll have to check out the MAF and reconnect it. I really hope it's NOT a fuel pump...
 
#9 ·
I dont think its the fuel pump mainly cause mine is brand new and runs strong reads correct preussre, voltage ect.. in my other thread we almost narrowed it down the the computer having an error, cant remember who told me this but thery said, They parted one car out and used the ECM out of that one in another car and the problem transferred thus making me think its the ECM but Idk for sure, which ECM do you have, ill go back on that thread and ask him the same thing if we all happen to have the same ECM than im going to start thinking diff..
 
Discussion starter · #10 ·
I have FTL3. Think I should reflash the tune, see if that changes anything?

---------- Post added at 12:21 PM ---------- Previous post was at 12:10 PM ----------

Also, different issue, I only register 93% throttle according to Torque with the peddle on the floor. Is this normal?
 
#11 ·
as far as the pedal thing Im not sure, for the tune I say why not, maybe itll work maybe not? cant hurt I dont imagine

---------- Post added at 12:55 PM ---------- Previous post was at 12:54 PM ----------

I would think with the peddle on the flor you should see 100% or maybe like 98-99 but could be a common thing
 
Discussion starter · #12 ·
Well I'll run the check valve bypass for a bit longer and see. And for the throttle, it is fully open, I had some one step on the peddle and went to the TB and it was full. Just wondering if the computer is holding back, ya know?

Thanks!
 
Discussion starter · #13 ·
It is not the Check valve. Still doing it with it bypassed. However, it seems to only happen when the A/C is on. Being a Texas summer, I didn't even think about it.
 
#14 ·
Idk but when my car was N/A it felt like it lost a ton of with the A/C on, it could just be normal, and the 93% throttle might be an issue, tell ya what though, do you have the gas pedal mod? I bet whats happened is your throttle cables stretched a bit and its not making it completely WOT sometimes, if you use the mod to raise your gas pedal you can hit it and be sure its at a 100% everytime
 
Discussion starter · #15 ·
See I'd be more focused on the A/C except it was recent that it started doing this. And if it is, then it's not disengaging all the time.

I have not tried the mod yet because I had somebody step on the pedal and I went outside to check and it was full open, to the stop.
 
#16 ·
My car drives sooo different with the AC on it makes me sick lol I feel yea on the texas heat but if its under 95 I wont even turn it on cause its so lame and eats so much gas. Blows ice but still isnt worth it
 
Discussion starter · #17 ·
Ha I may start doing that. But not until it stops being over 104! Leave work and step in a suana, wearing a full body, dark green suit, and then into an oven!
 
Discussion starter · #18 ·
Just as an update it does seem to only happen when the AC is running. My question is why would it all of a sudden cause a power draw? It never did before. But we did replace the AC pump when we first got it...Not sure that would make a difference though.
 
#19 ·
It's normal to feel a little drop in power when the compressor cycles, and if you're clutch/compressor is functioning it should cycle every minute or so. My compressor is short cycling right now so I feel a sudden dip in power every 5 seconds. Have you checked to see if your system is cycling properly?
 
#20 ·
JakeSixx said:
Just as an update it does seem to only happen when the AC is running. My question is why would it all of a sudden cause a power draw? It never did before. But we did replace the AC pump when we first got it...Not sure that would make a difference though.
Click to expand...
If our cars are doing the same thing that im talking about Its not the A/C its so hard and sudden, mine also was doing it with the A/C off
 
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JakeSixx
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