2003 Cobra 73,000 miles. Car starts and runs fine, but at WOT the car falls on its face then goes faster after 3-4 seconds. Air Fuel gauge also goes in the red (lean) side. Where do i start? I have a Diablo Predator. Can i diagnois my issue with the handheld tuner?
Air Fuel Gauge going to Lean @ WOT!
- Thread starter CoBl2aKi/\/g
- Start date
Check your batt. / charging voltage. When was the last time you changed your fuel filter?
w
just replaced my fuel filter like 2,000 miles ago
just replaced my fuel filter like 2,000 miles ago
Take it to a dyno to confirm your suspicions.
dont have one around here. i know there is definitly a problem because it goes to lean and the car lacks power under wot
can i use the predator to see my fuel pressure from the pump is dropping? if my fuel pump pressure is dropping then it is the fuel pump correct?
Could be a few things really. Maybe start by checking all your plugs. I have similar mods as you and my FPDC was maxed out, so I added a BAP. Did you check your predator for any codes? Have you hit the rev limiter lately? Maybe a FRPS blown or going bad. Mine was going bad and still drove and started. Also what WB are you running? Just trying to throw ideas out there.
EDIT: Yes you can datalog with your predator. Check the manual for the abbrevitations for fuel pump duty cycle and fuel pressure.
EDIT: Yes you can datalog with your predator. Check the manual for the abbrevitations for fuel pump duty cycle and fuel pressure.
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I dont think my fpdc is maxed because i been running this setup for over 5 years with no issues. i will check my plugs, but would spark plugs cause it to run lean? also like i said the car runs fine at idle and normal driving. No Check Engine light on neither. Never hit the rev limiter lately. Its not a wideband. its just a air/fuel autometer gauge. The autometer gauge is always pegged in green when at WOT, now, just recently at high rpms it goes to the red. Never ever has my gauge gone to red untill the delay at WOT now
if it isnt a wideband gauge is isn't worth looking at. the narrow band gauges don't help you at all, and i wouldn't know why anyone would buy one.
either get a real wideband, or get it to a dyno, or learn to read plugs like a pro. plain and simple.
either get a real wideband, or get it to a dyno, or learn to read plugs like a pro. plain and simple.
+1 those gauges are only good for one thing.....a light show.
well guys im sorry like i said when i bought the car i was only 18 years old. didnt know anything about cars and didnt know of svtperformance at that time sorry. i just know i got an issue and like i said the gauge at wot would always be pegged in the green, not it goes to the red at wot and the car falls on its face. "Mustanginky" instead of beating me up, why dont you give me some good information. Should i just replace my FRPS and take a shot at that? it looks like those go out alot! and i have 73,000k miles on my car with the original one.
is the FRPS easy to change?
should be pretty easy to change.
how am i beating up on you? i gave you advice, and helpful advice at that. those narrowband 02's are worthless and do nothing. your assuming it's going lean (and it very well could be) because it's running rough. but your basing your assumption it's lean off of a light show gauge which isn't accurate.
how am i beating up on you? i gave you advice, and helpful advice at that. those narrowband 02's are worthless and do nothing. your assuming it's going lean (and it very well could be) because it's running rough. but your basing your assumption it's lean off of a light show gauge which isn't accurate.
The FRPS is 2 bolts on the Fuel rail.. pull the vac line off of it and smell it.. if it smells like gas it could have popped but usually you will have more issue with it than just at WOT.
-FRPS
-Pump going south
-IAT is bad
-MAF could be dirty ( when was the last time you changed your air filter )
-FPDM could be going out
I would start with the Maff and FRPS. When you go WOT how long does it take for the problem to pop up. Is it instant or does the car ramp up like 10 pounds of boost then go lean?
-FRPS
-Pump going south
-IAT is bad
-MAF could be dirty ( when was the last time you changed your air filter )
-FPDM could be going out
I would start with the Maff and FRPS. When you go WOT how long does it take for the problem to pop up. Is it instant or does the car ramp up like 10 pounds of boost then go lean?
the hesitation is instant but it takes 2-3 seconds to go to the lean side
I would datalog first like I mentioned above. Check to see what your fuel pressure, fpdc, and voltage. Also make sure you release the fuel pressure by pushing down the schrader valve on the pass side fuel rail before you take the frps off! If not you'll have gas go everwhere, trust me I know!
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ok np. i think im going to replace the frps anyway. its only 100 dollars and its a good shot that it is bad because its the original one and i read countless threads of people replacing them. going to pick it up now and ill let yall know tonight what happens. I will also look at my maff meter to make sure it is clean and not dirty. The symtoms i am having does that sound like a frps?
dont waste your money throwing parts at it. look at it this way, spend the money for someone to properly diag it. usually the cost is 65-100 bucks. then try and fix the car from that diag that you paid for.
first id scan it for codes that may not trip the check engine lamp.
next data log it
lastly manually test components
Ok the FRPS didnt do anything. Here is the datalogging data.
Gas acceleration wot
0.2V MAF V
39psi FRP
10DEG SPARKADV
79.6% LOAD
-41% SHORT TERM F
-41% SHORT TERM F
0.94V THROT POS BE
GAS FUEL
39PSI FRP
2.76V FRP V
2.61V FTP
127.92H20 FTP
76F IAT
Gas acceleration wot
0.2V MAF V
39psi FRP
10DEG SPARKADV
79.6% LOAD
-41% SHORT TERM F
-41% SHORT TERM F
0.94V THROT POS BE
GAS FUEL
39PSI FRP
2.76V FRP V
2.61V FTP
127.92H20 FTP
76F IAT
this might sound stupid, but all i did was plug the predator in a open data logging. i never started the car at all when i wrote this information down. Is that correct?
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