cobra is bogging down after WOT pulls

[redfire03 svt]

cobra is bogging/hesitating down after WOT pulls

The cobra is bogging/hesitating down after WOT bursts. The WOT pull is fine, it is when I get out of the throttle and back in it, that’s when it occurs. It happens just for a few seconds then it gets back to normal. What could I check, or do you recommend I should be looking at to try and pin point the culprit. It’s almost like the motor is flooding, that type of feel.

Thx fellas

 

[R.D.P.]

Research PPRV Delete. Doesn't sound exactly like what I've heard of as far as symptoms, but it could be what you need to do.

 

[cj428mach]

What is your fuel system? It does sound like a returnless issue.

Got a wideband?

 

[redfire03 svt]

I do have a wideband, and my fuel pumps and 60lb injectors are at 85% duty cycle during WOT blasts. Fuel system is stock other than the boost a pump and 60lb injectors.

 

[cj428mach]

I agree, sounds like a tune/pprv issue.

 

[03' White Snake]

How is your BAP wired?

Had a similar issue with mine and it turned out to be how the BAP was wired. KB instructions tell you to wire the BAP post FPDM when in fact it is easier to tune with the BAP hooked up before the FPDM.

With the BAP hooked up after the FPDM, the computer cannot monitor the voltage going to the pumps, it was causing my pumps to go into over load protection. As soon as I changed the wiring it was fine for 2-3 years before updating the fuel system.

 

[redfire03 svt]

I have had two different tuners tune the cobra, and it still bogs after WOT blasts on both tunes. I don't think it is in the tune. I will check the boost a pump wiring. How exactly are you saying it should be wired?

 

[Bdubbs]

I have had two different tuners tune the cobra, and it still bogs after WOT blasts on both tunes. I don't think it is in the tune. I will check the boost a pump wiring. How exactly are you saying it should be wired?

Wire upgrade a "pre" FPDM.

 

[cj428mach]

I have had two different tuners tune the cobra, and it still bogs after WOT blasts on both tunes. I don't think it is in the tune. I will check the boost a pump wiring. How exactly are you saying it should be wired?

Its real easy to see if its a fueling problem by logging Fuel Pressure Drop Across injectors. If its a fueling/tune problem your pressure will drop almost if not all the way down to zero for a split second.

 

[speeddemon2000]

I would wire pre FPDM like others have said. You may also be experiencing thermal shutdown from your FPDM.

Check Fuel Pressure Drop Across injectors like said before.

Good luck! Let us know what fixes it.

 

[furious465]

The cobra is bogging/hesitating down after WOT bursts. The WOT pull is fine, it is when I get out of the throttle and back in it, that’s when it occurs. It happens just for a few seconds then it gets back to normal. What could I check, or do you recommend I should be looking at to try and pin point the culprit. It’s almost like the motor is flooding, that type of feel.

Thx fellas

I bought my car back in November and I had the same exact problem you are describing. If I nailed it in 1st gear it would pull all the way through, I would let off the gas, switch to 2nd gear and hit the gas and it would hesitate for a second and then start pulling hard again all the way through, let off the gas, shift to 3rd, hit the gas and it would hesitate once again. It was pissing me off, here I have this 500hp car and it sucks I cant drive through the dam gears under WOT. It did not do it just normal driving, only when I revved out the gears under WOT. So I did some research and decided to give the PPRV delete mod a try. Well it fixed my problem and the car doesn't hesitate at all now. It was the fix for my hesitation and sounds to me like you have the same problem I had.

 

[redfire03 svt]

Looks like I will try the delete first since it seems easiest. If that does not fix it I will rewire the BAP.

 

[01yellercobra]

Rewiring the BAP would be easier. In order to do the PPRV delete you have to drop the tank. If it is a shift hesitation it can also be tuned out.

 

[redfire03 svt]

My cobra has a built auto tranny, the shifting is perfect. Issue is right after WOT blasts and I tip back into the throttle it bogs.

 

[cj428mach]

My cobra has a built auto tranny, the shifting is perfect. Issue is right after WOT blasts and I tip back into the throttle it bogs.

Its all just a guess unless you datalog. The reason it hesitates on shifting with manual cars is because people let off on shifting. When you let off on a returnless system after a wot blast fuel pressure spikes so the ecm reduces fuel pump output. Then when you accelerate again there is no fuel.

 

[R.D.P.]

If your still in ATL, there should be only one person ever tuning your car - Bob Kurgan. Also - just because your not hesitating at the top of the rpm range, doesn't mean it's not leaning out more than it should. BAP wiring isn't the most likely cause IMO, but it's something easy to check and eliminate. Just pull apart the driver side of your trunk.

 

[redfire03 svt]

How is your BAP wired?

Had a similar issue with mine and it turned out to be how the BAP was wired. KB instructions tell you to wire the BAP post FPDM when in fact it is easier to tune with the BAP hooked up before the FPDM.

With the BAP hooked up after the FPDM, the computer cannot monitor the voltage going to the pumps, it was causing my pumps to go into over load protection. As soon as I changed the wiring it was fine for 2-3 years before updating the fuel system.

Did you touch the tune after you rewired?

 

[cj428mach]

Did you touch the tune after you rewired?

No you don't have to mess with the tune on a BAP.

 

[whitedevil95]

The hesitation between shifts can be tuned out. Mine doesnt really have that at all. But If I get on the throttle and got WOT let off then try and hammer it again. I will also get that hesitation. Its the PPRV. I could do a delete but if im droping the tank im gonna just do a full fuel system.

 

[MS03DSG]

How is your BAP wired?

Had a similar issue with mine and it turned out to be how the BAP was wired. KB instructions tell you to wire the BAP post FPDM when in fact it is easier to tune with the BAP hooked up before the FPDM.

With the BAP hooked up after the FPDM, the computer cannot monitor the voltage going to the pumps, it was causing my pumps to go into over load protection. As soon as I changed the wiring it was fine for 2-3 years before updating the fuel system.

^^ THIS. Same thing here