Ford Mustang Forums banner

1 - 20 of 20 Posts

·
Registered
Joined
·
4,628 Posts
Discussion Starter #1
I just ran a [email protected] on my new NX plate for the Windsor\RPMII intake combo; letting out at the 1,000ft mark & coasting through the finish line. My only problem; the car will not RPM to 6,200rpm like it used too. Typical DA being 5,500-6,000ft with high moisture(spring wet weather). It'll pull fine to 5,800 & it feels like everything just cuts off in second gear; I shift quickly to again deal with it shutting off right at 5,800rpm in third gear. this happens in all gears; I just short shift 1st due to anxiety\ being over anxious... Keep in mind; I've been fighting this problem since last year with my Zex wet nozzle system; before I installed the plate.I have fresh & more than enough spring rate valve springs. Comp XE274 cam, 75mm Accufab T.B, 4" Anderson air intake setup, 255lph pump, new filter, etc. I solder all my wiring, run premium gas, pull 4 degrees out for N2O passes.... I'm kinda at my wit's end. Dyno the car on a Dynojet & it pulls all the way to 6K plus; N2O on or n\a. I'm narrowing the plug gap to .028 from .032 in the hopes that helps in case I'm blowing out the spark. Any other experienced thoughts?

https://www.youtube.com/watch?list=PLq_5ull3kUe8AHTJHH6RApe1C2VBU902v&v=WARPAprdEhA
 

·
Registered
Joined
·
7,019 Posts
I just ran a [email protected] on my new NX plate for the Windsor\RPMII intake combo; letting out at the 1,000ft mark & coasting through the finish line. My only problem; the car will not RPM to 6,200rpm like it used too. Typical DA being 5,500-6,000ft with high moisture(spring wet weather). It'll pull fine to 5,800 & it feels like everything just cuts off in second gear; I shift quickly to again deal with it shutting off right at 5,800rpm in third gear. this happens in all gears; I just short shift 1st due to anxiety\ being over anxious... Keep in mind; I've been fighting this problem since last year with my Zex wet nozzle system; before I installed the plate.I have fresh & more than enough spring rate valve springs. Comp XE274 cam, 75mm Accufab T.B, 4" Anderson air intake setup, 255lph pump, new filter, etc. I solder all my wiring, run premium gas, pull 4 degrees out for N2O passes.... I'm kinda at my wit's end. Dyno the car on a Dynojet & it pulls all the way to 6K plus; N2O on or n\a. I'm narrowing the plug gap to .028 from .032 in the hopes that helps in case I'm blowing out the spark. Any other experienced thoughts?

https://www.youtube.com/watch?list=PLq_5ull3kUe8AHTJHH6RApe1C2VBU902v&v=WARPAprdEhA
what is the jetting? what does the rest of the fuel system consist of?
 

·
Registered
Joined
·
4,628 Posts
Discussion Starter #3
Sorry, been working on friend's cars for a while now & spent little time on my own. The fuel pressure regulator failed & i replaced it. 45 PSI unplugged & 36-38 with vacuum attached. Stock fuel system with the exception of a 255lph pump. Jetting as recommended by NX for a 150 shot; 70 N2O jet & 39 fuel jetting on the plate. I've made a few more passes with the same end result; short shift below 5,750rpm & run 11.90's every time. Try to run & shift at 5,800 rpm or more; the car acts like it cuts off completely. Quickly shift; it's back on. This leads me to believe it's a fuel starvation issue. I think the best thinking for me to do is dyno it with an O2 sensor stuck up her as & see if if she is going lean. If so; Aeromotive 340lph pump time. If not; unlikely but valve spring check time...
 

·
Registered
Joined
·
7,019 Posts
Sorry, been working on friend's cars for a while now & spent little time on my own. The fuel pressure regulator failed & i replaced it. 45 PSI unplugged & 36-38 with vacuum attached. Stock fuel system with the exception of a 255lph pump. Jetting as recommended by NX for a 150 shot; 70 N2O jet & 39 fuel jetting on the plate. I've made a few more passes with the same end result; short shift below 5,750rpm & run 11.90's every time. Try to run & shift at 5,800 rpm or more; the car acts like it cuts off completely. Quickly shift; it's back on. This leads me to believe it's a fuel starvation issue. I think the best thinking for me to do is dyno it with an O2 sensor stuck up her as & see if if she is going lean. If so; Aeromotive 340lph pump time. If not; unlikely but valve spring check time...
good idea with the WB, i would look into the HFP 320lph pump (better price, better warranty and it wont overpower the regulator like the 340 has), besides... the stock fuel lines are probably the choke point anyhow. if you dont have a "hot wire kit" you should consider that too.
 

·
Registered
Joined
·
4,628 Posts
Discussion Starter #5
good idea with the WB, i would look into the HFP 320lph pump (better price, better warranty and it wont overpower the regulator like the 340 has), besides... the stock fuel lines are probably the choke point anyhow. if you dont have a "hot wire kit" you should consider that too.
Sorry, what does "WB" stand for? HFP is not pulling anything on my internet searches; full name? Also, what is a hot wire kit? Damn, I feel like a newbie! ;)

Do you really think the stock fuel lines are a restriction while only making about 435rwhp, corrected for elevation dyno, on the juice? In reality, I'm really only making an at best 400rwhp on the juice...
 

·
Registered
Joined
·
7,019 Posts
Sorry, what does "WB" stand for? HFP is not pulling anything on my internet searches; full name? Also, what is a hot wire kit? Damn, I feel like a newbie! ;)

Do you really think the stock fuel lines are a restriction while only making about 435rwhp, corrected for elevation dyno, on the juice? In reality, I'm really only making an at best 400rwhp on the juice...
sorry WB=wideband. HFP=high flow pumps, they are now quantum fuels, [email protected] is a member here and he is a GREAT guy! shoot him a PM, customer service second to NONE! he also has hot wire kits, the hot wire kit is basically a relay and large feedwire that runs directly to your battery (fused of course), it uses the OEM fuel pump power wire to trigger the relay, but power for the pump comes directly from the battery thru the dedicated wire... this can extend the life of your pump and lessens voltage drop which can cause the pump to loose efficiency.

im not saying the stock lines are definitely the issue, but they arent helping. ive had issues before with the flexable lines that lead from the hard lines on the chassis to the fuel rail supply lines kinking and cutting off fuel flow (again, not saying its a problem but i could see the car running fine on the dyno-stationary, and acting up while actually in motion and the lines kinking), its just something i would look at. while your at it, inspect the flexable lines at the tank as well.
 

·
Registered
Joined
·
7,019 Posts
i just remembered, i actually have one of the HFP 320lph pumps left from the three i was using with my on3 fuel hat. it barely had any idle time on that setup before i parted the car, i also have a complete new install kit... if your interested i will make you a good deal on it. not pushing anything, i wont mention it again, if interested PM me.
 

·
Registered
Joined
·
7,019 Posts
could be blowing out the spark. I have mine gapped at 25.what are you running for ignition? what plug?
i was curious as well, he said he tightened the gap to 28 but never said what plug. a recessed tip plug might help, but it shouldnt be necessary at his power level. i believe its a fuel issue.

I may have missed something but, will the car do this on just motor or is it only when the nitrous is on?
the strange thing is he said it ran fine on the dyno both N/A and on the jug, only has this problem on a pass, he didnt say, but im assuming on the bottle only.

i wouldnt think its a kit issue since he said hes been fighting it since last year with a different kit.
 

·
Registered
Joined
·
734 Posts
You're only pulling 4 degrees for a 150 shot? If the 150 shot maintains fuel pressure and works fine on the dyno, then I don't think fuel is the issue. I could be wrong though. I feel that the fuel supply should be roughly the same whether it be on dyno or on a track. The load simulated by the dyno may not be as much load as you are experiencing on the track. There may be a timing issue?

Tightening up the gap and getting an ignition box isn't a bad idea, neither is running a cut back ground strap plug like the Autolite race series.

You can do a quick run on the spray to the 5800 power loss, but instead of shifting and continuing maybe you should just kill the engine, pull over and read your plugs. They will tell a lot about fuel vs spark issues, help you determine if you have detonation or spark blow out.

If it were my car, I would try the simple change of dropping another 2 degrees base timing and giving it another go. See if she cuts out at 5800 again. You aren't going to do any harm by that and if she keeps pulling past 5800 then maybe you are getting detonation at your current timing setting - which stops your power production?

Just my quick thoughts on it. I hope you get things sorted quickly.
 

·
Registered
Joined
·
4,628 Posts
Discussion Starter #12
UPDATE: okay, after password change hell & back; I can finally post my findings! Sorry to all whom were following, wondering, & your helpful posts.
I became frustrated, talked to the engine builder, & we came to the conclusion that more than likely I killed something in the valve train. I tore into it & sure enough there was damage.
2 broken inner valve springs, 2 dead valve stem seals, & one collapsed lifter(maybe 2). Engine builder swears I "over rev'ed it"; but it's not possible with my rev limiter set low(6K)that I happen to never bounce off of. But, I believe I did the damage revving the engine hard when it was still cold during last winter. Happens to be the same time a roller rocker just happened to mysteriously fall to the wayside off the valve after a quick show off rev. All the springs were down to 95-105lbs seat pressure; I'm just replacing them all along with the viton seals. I'll report back when i hit the track; hopefully on August 11th during our Mustang vs Mopar vs GM night... ;)

As to questions: Yes, I only pull four degrees timing. Track elevation is 4,4xxft elevation. Add in our typically miserable DA & you have pretty thin air; I.E. we don't have to pull as much timing as you guys at lower elevations do. Yes, what had me thinking fuel was the fact that the motor rev'ed all the way to 6K & didn't have the lower rpm "cut-off" issue. I believe that one inner spring died last October & why it ran a couple tenths slower at the very last event before winter hit. The other I killed last while racing in late May & why she ran poorly in June. I'm just amazed I didn't burn a valve or piston; let alone dropping a valve & wasting a motor....
 

·
Registered
Joined
·
7,019 Posts
good to see ya back, i was beginning to wonder. check back in when its fixed...
 

·
Registered
Joined
·
4,628 Posts
Discussion Starter #14
Well, I finally made it out to the track and...... No bueno. Launch & then the car would immediately fall on it's face:
I checked timing & a dozen other things to just do it again. I decided to disconnect the nitrous & ran 13.004 to 12.91 on motor all night; which are new N/A bests for my car up here at this elevation in N/A form:
Sooo, this is something new too me; never had a nitrous issue. It feels like the system is shutting off a millisecond after firing or the fuel is working & the nitrous is not. I verified power to the Zex control box, purge function, etc. I then decide to see if it might be an issue with the car & pulled KOEO codes. Boy, were there allot of them. But only two stuck out; #29 & #87. I suspected the VSS was going away since the car's idle while coming to stops or throwing it into neutral & coasting; the car would die. So that will get replaced immediately. The fuel pump circuit fault(check inertia switch) has me scratching my head. But should be easy to test by simply wiring in a switched bypass for testing purposes. If the system fires & stays on after adding the bypass; it would explain why the Zex system was shutting off... Surprisingly, i was unable to get the car to perform the KOER test; via testing unit or by the old school ground out methods that have always worked in the past. Maybe i simply need to fix a bunch of these codes first?
 

·
Registered
Joined
·
734 Posts
No matter what you do, fixing those codes isn't going to hurt.

The launch and stall in your first video is so obvious. The car simply isn't making the power that it is off the bottle, when it should be making a ton more. Your suspension is unloaded up front for the first gear in NA form, but on the spray the front end lifts and then sloshes back down like dead weight.

I don't know that a simple four degrees of timing retard would make you bog so drastically (compared to the NA run), unless maybe she went pig rich and left you way down on power. That would make me want to check the nitrous lines for solenoid function and obvious nitrous venting when you hit the button.

You mentioned that you checked the purge for power, but I'm not sure if you meant that you checked for visible spray upon activation. Does the purge vent visible nitrous? Even if it does, if the purge solenoid is plumbed in before the ZEX nitrous solenoid, then it may not be related to your issue. If your purge wrks fine and you see visible nitrous release... then that only means fresh nitrous is in the line leading to the ZEX solenoid. If the ZEX solenoid has failed inside the box, then nitrous will not pass through it, even if it is powering on correctly. That would mean you could get fuel side solenoid activation (ZEX box has two solenoids in it) and no nitrous pass through (because of a faulty nitrous side solenoid, or clogged line perhaps)?

I imagine a simple way to test the nitrous output from the ZEX box would be to disconnect the AN fitting from the outlet port on the box and then fire the system up with WOT pedal and key in the on position. You may have to bypass the fuel pressure safety switch unless you do this with the car running. If you can get the box to activate, but no nitrous sprays through, then you should know the solenoid is dead. If it does spray nitrous, then I'm way off base in my remote assessment ability.

I'm just reaching for possible explanations, trying to help think of things you may not have yet covered.

Too bad I can't see the exhaust color from the video angle. That may give a clue, as would pulling your plugs to check for wetness... or getting a wideband oxygen sensor onboard.

Keep us updated. Glad the spring issue got fixed, but it sucks to hear you have continued issues on the spray.
 

·
Registered
Joined
·
4,628 Posts
Discussion Starter #17 (Edited)
UPDATE: It was the rear end fuel cutoff thingy. The hard launches & probably the age of the inertia switch was the problem. I bypassed it & was able to confirm the solenoids were functioning. So, I took it out on the street for a couple test hits way out in the middle of nowhere... ;) Let's just say I'm rather anxious for Sept 9th Midnight Drag Bash to get here real quick!
 

·
Registered
Joined
·
7,019 Posts
UPDATE: It was the rear end fuel cutoff thingy. The hard launches & probably the age of the inertia switch was the problem. I bypassed it & was able to confirm the solenoids were functioning. So, I took it out on the street for a couple test hits way out in the middle of nowhere... ;) Let's just say I'm rather anxious for Sept 9th Midnight Drag Bash to get here real quick!
this makes sense, since you mentioned it worked fine on the dyno (no G forces from a launch).
 

·
Registered
Joined
·
4,628 Posts
Discussion Starter #20
Well, good news. Made it back out to the track & ran [email protected] I'll run it again here on Oct. 14th & try to get everything out of her i can. 11.6 is a definite reality; 11.5 would make me happier. The hard part is that we are in fall full swing. Trying to get a 1.5 60th on my teeny 8.5" slicks will be tough due to the ambient temps likely being in the 60 degree range. Stay tuned.... ;)
 
1 - 20 of 20 Posts
Top