Rev limiter issues

[99 Stangbanger]

What will cause my car to shut down just like a rev limiter will do?

The rev limiter is set and confirmed through my Diablo programmer at 7200 RPM.

Car is falling on its face /shutting down at 6800.

Any clues as to what may be the issue on my 99 cobra? Been this way since last tune but cant see anything in the tune that would casue this.

Mods...
V2 SQ with AFM power pipe.
9.7 lbs of boost at 6800 rpm
Snow Stage 2 Meth. 50 / 50
430 gears. 410's on order and going back in asap!

Other bolts on crap that dont matter here.


Thanks for any advice:biggthump

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[qwik01cobra]

So the car has a handheld tuner and has never been professionally tuned?

 

[[email protected]]

Fuel pressure could be dropping, MAF could be pegging, etc. Definetly don't go WOT again. We're giving out free dyno coupons at our open house this weekend. Drop by and pick one up then on Monday we can dyno your car for free and see what the issue is. :headbang:

 

[99 Stangbanger]

Fuel pressure could be dropping, MAF could be pegging, etc. Definetly don't go WOT again. We're giving out free dyno coupons at our open house this weekend. Drop by and pick one up then on Monday we can dyno your car for free and see what the issue is. :headbang:

I have a mafia and its set at 2 and confirmed in the tune as well. Would this even cause my issue?

FP at WOT was 52 -54 and A/F was 11.4 at WOT, 440 RWHP and 9.7 lbs of boost shutting down just like a rev limiter or speed limiter at about 118 MPH or 6800 rpm. Looked at tune and there seems to be no speed limiter set either.

TR 6's gapped at 32.

Q.. I was still making power and TQ at 6700 rpm and it hit what seems to be the rev limiter, wouldnt if there was a the spark issues( blowout) cause me to loose power not keep gaining?

Thanks for the free offer on the run. I'm currently in FL but will be back in IL next week but not by Monday:-(

 

[99 Stangbanger]

So the car has a handheld tuner and has never been professionally tuned?

Yea its a Diablo but was tuned professionally. I'm at a loss here I have no idea whats the issue

 

[[email protected]]

Thanks for the free offer on the run. I'm currently in FL but will be back in IL next week but not by Monday:-(

Give us a call when you're back in town. I should still be able to set you up with a free run. :biggthump

 

[Dana]

Does it shut down in every gear at the same 6800?

 

[99 Stangbanger]

Does it shut down in every gear at the same 6800?

I think it did from the 1st -3rd hit I did on the way home from the last tune in IL.

I have only put on about 100 miles since its last tune in May and now I just added meth and a 3.12 pullie and a power pipe so I went back in for more pulls and tuning here in FL. As far as I know all pulls were only in 3rd and each one shut down@ 6800 each and every time.


What I can say is that back in May when I left the shop after my tune in IL I came accoss a Car that I messed with or tried:-( on 355 from a toll booth and my car broke up 1 -3 and fell on its face. I was so surprized as was my passenger. I never had the chance to look down at my Tach (PRIOR TO THE RAPTOR SHITLIGHT). But I know it felt way short of the 7200 that the rev was set at the day I was going to move on that car next to me. I knew right then that there was something really wrong. I have hit rev before so I know what it feels and sounds like.This is the same feeling and sounds the same as well.

Right now I have the raptor set at 6700 RPM. I never really rev past 7100 anyways.

I called the tuner on the way home and expained the issue, guessed it might be plugs since I didnt do what he asked in the 1st place and swap them out prior to my time at the shop with him. So when I got home that day I went and picked up new plugs and swapped the Motorcrafts to NGKTR6's gapped at .032 but never had the time to get the car back on the road except to go around the corner a few times and I never got into the revs. My full intentions were to get back to the original tuner cuz I had a meth kit already on order and the other stuff so once I installed that stuff I was going to have him look into it agin. He agreed as well. Well, time fell way short and I left before ever seeing the tuner in IL and installed the stuff here in FL. Found a Shop 3 miles away that tunes mostly Stangs.

I installed the Meth Injection Kit, New pullie and AFM Power Pipe. Went to the speedshop here in Melboure and ran the car with and without Meth and tuned, also with it on and sparying at 3- 4 lbs of boost but set to shut off at 7200. Each time she still hit the rev or whatever and fell on its face.

I just went out tonight and bought new Autolites 103's and will gap them to .025 per the last tuners request. I have a slot with the speedshop at 10:30 AM here on Friday so I'm gping to run it as is with the new plugs and see what she does.

Some have said, Knock sensor, Blowout, fatten the fuel on top, Timming, Valve Float, Faulty Foucs FP or one that is maxed out, MAF Pegged, MAFIA issue, remove timming, Bad tune, corrupt Computer ect...

I Trust the tuner in IL who last tuned my car @100%. I just wish I could have found the time to get it back to him. I'm comming back next week so hopefully he can fit me in asap to fix or help figure out what is wrong here.

BTW.. The car runs flawless and clean with plenty of power untill she hits 6800. Onthe dyno she was still making power and TQ till it fell on its face at 6800.

What gives?

 

[99 Stangbanger]

Give us a call when you're back in town. I should still be able to set you up with a free run. :biggthump

Thanks Dave:biggthump

 

[Bob_Kurgan]

tom.. i appreciate you trying to protect my reputation, but its no problem if you say its me.. we are on great terms... there is nothing wrong in the tune, i feel 99.9% comfortable saying that.. here was my reply from cmc..

"someone was me.. i think the knock sensors are possibly pulling timing??

The car pulls beautifully to 67-6800 and power,torque, and a/f were solid.. I originally though it was spark blowout as well and recommended you to put in new plugs and gap them down to .025.. you said you did that so i am stumped. Maybe it is spark blowout still as shane is saying? All i know is that i tuned it up here without meth and someone else tuned it in Florida with meth and the issue is still there.. so, i would have to rule out that its in the tune. 2 guys tuning on it with the same issue at the same RPM means most likely mechanical."

last thing id like to note.. i dont feel comfortable with you spinning the motor any higher then 6800...

 

[99 Stangbanger]

Spinning the motor any higher then 6800 She wont go over 6800 even with a tail wind and luck. Or do you mean till we get it worked out?


I will just pick up my parts from the speedshop, skip the next pull and be on my way.

As always, look forward to talking soon.


edit:

Should be back home by between the 20th and the 25th forsure. Have to load my BOBCAT and haul it back 1st then come back and gather convoy of toys, tools and dogs

BTW.. what about this..."torque based (?) and injector limiters" all turned off ? Never looked into that

Ah hell, Seeya in a few man:lmao: