My mods are CAI, off road x, flowmasters, and a tune. When I shift (rather slowly - don't care to be banging gears) on WOT often my Cobra will hesitate for a split second and then nearly give me whiplash. I used to think this was it building boost again, but after looking around this seems like the fuel issue that many people talk about and do the PPRV delete for. Should I contact my tuner to help the problem or do the PPRV delete or is this something else? THe PPRV delete issue seems to happen when the fuel pumps are under heavy load and I find it hard to believe that mine are with it running at stock boost levels.
Basically Stock '03 Cobra Hesitating on Shifts
- Thread starter WireMesh
- Start date
it's going to be the pprv, replace the hat (which is what I did) or do the delete. good luck
With your mods a decent tune would fix it. I was able to get it under control self tuning by reading this thread and copying/modifying the tables posted on modford. I was running a BAP, 60's and a Whipple at 15psi at the time, I'd look for a new tuner if they can't get it right.
http://www.svtperformance.com/forum...ng-bogging-hesitation-between-high-rpm-shifts
http://www.modularfords.com/threads/24834-Dyno-graph-and-questions/page3?p=249341#post249341
http://www.svtperformance.com/forum...ng-bogging-hesitation-between-high-rpm-shifts
http://www.modularfords.com/threads/24834-Dyno-graph-and-questions/page3?p=249341#post249341
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Thanks! I will look into that. I thought it would be the tune because I'm not even pulliied...
concur with cj428mach...
With no pulley and minimal mods you can for sure get it tuned out like cj428mach says. PPRV delete's are kind of a hack because it's so difficult to get the hose bent and in there. You'll see plenty of threads of failed PPRV delete's with popped off hoses etc. and guys getting towed home. Some get lucky and it works for them. Aftermarket hats and pumps are expensive and you don't need that yet. Get your tuned adjusted and you'll be good to go.
Thanks for the info on the downsides of doing the PPRV delete! It did seem like a sort of hack with people saying you would have to leave the key partially turned to prime the car to start it.
Replacing the hat with an aftermarket unit and pumps essentially eliminates the PPRV as well. Honestly the starting issue wasn't that bad. It took an extra second or two of cranking to fire. Once in a while someone would notice and ask why the hard starts? Pretty easy explanation. The only time I ever had problems was when the car was fully warmed and heat soaked and I stopped somewhere for 20 min or so. Came back out to start it and it'd barely catch almost immediately as you cranked it and sort of stutter for a second and die. The second crank would do the normal long 1 to 2 second crank and then it'd start. Overall very minor and livable.
Once I switched a return style fuel system all that went away. Starts like OEM again.
Ive been stock...with about same mods...
more info about car....miles...any work done on engine..
how long have you owned. .
more info about car....miles...any work done on engine..
how long have you owned. .
usually the hesitation becomes an issue after you mod the fuel system, typically a BAP, then the cars actual fuel supply no longer matches what is in the tune... the pcm tries to anticipate fuel demand by load and then has a feedback process based on injector d/p to fine tune it... you let of the gas, fuel pressure spikes, the pcm dials back the fuel pumps, you grab the next gear, nail it, and because the tune is not adjusted properly, you live more on the feedback than on the front end, so pressure drops, car hesitates, before the pumps can spool back up and raise injector d/p again... bunch of stuff out there how to fix it in you tune, anybody who has been tuning these cars should be able to get it right...
Unless you had a BAP installed in anticipation of future mods, not sure why you would be having these problems, though there were some issues in the early stock tune, which people quickly fixed, even with the canned tunes... check the trunk, in the spare tire well, or driver's side, behind the panel near the trunk hinge... red box, boost-a-pump, or something similar... if not, need more data about the car....
Unless you had a BAP installed in anticipation of future mods, not sure why you would be having these problems, though there were some issues in the early stock tune, which people quickly fixed, even with the canned tunes... check the trunk, in the spare tire well, or driver's side, behind the panel near the trunk hinge... red box, boost-a-pump, or something similar... if not, need more data about the car....
I have had the car for nearly a year. I bought it from a guy who only had it 6 months right out of college then decided he couldn't pay for it because he was going to go back to get his masters. He bought it from the original owner who was an older man who traded it into the dealership for a mini van. The car currently has 77,xxx miles on it and is my daily driver (I got it with 67,xxx). No work has ever been done on the engine. The oil has always been changed when it is supposed to be with synthetic. A few months ago a friend of mine who used to own an 03 Cobra noticed that my intercooler pump was not pumping (beginning of the summer). He said this was a common issue and I had not had overheating issues because it had a stock pulley. I fiddled with the wire connecting the pump and it has been chugging along ever since (I check every time I get gas). Within the past weekend my ABS light has been on about half of the time and I am still waiting for it to be on when I pull in the garage so I can read the diagnostic code. Here is a complete list of everything I know of that has been done to the car:
- Bassani catted x pipe (guy before me) with the cats cut out (me)(they broke and were clogged)
- Flowmasters cat back exhaust & muffler (guy before me)
- MIL eliminators (me)
- Originally just had a K&N filter in the stock filter box (probably guy before me) but switched to the JLT next gen CAI (me)(in fender)
- Bama tune on XCal 3000 (me)
Mods that should not affect problem:
- 3 90mm Metco idlers to replace the stock ones (me)
- MGW shifter (guy before me)
- Raxiom blacked out taillights (me)
- Sequential tail light kit (me)
- Hub centric spacers on rear wheels (guy before me)
I had previously datalogged my car and it seemed to be running rich but I was fine with that since it's better to be safe than sorry. I recently emailed Bama that I would like to datalog the tune and told them I think it is running rich and it hesitates on shifts (attached the links mentioned previously). They were very nice and told me what params to datalog and to get back to them. So now I am just waiting until I get a good chance to datalog it.
Also, I am located in Texas where summers can get hot! The car has been autocrossed 3 times and never had issues. Aside from the occational 1st or 2nd gear pull, I am easy on the car and it never goes on top speed highway runs or anything like that.
- Bassani catted x pipe (guy before me) with the cats cut out (me)(they broke and were clogged)
- Flowmasters cat back exhaust & muffler (guy before me)
- MIL eliminators (me)
- Originally just had a K&N filter in the stock filter box (probably guy before me) but switched to the JLT next gen CAI (me)(in fender)
- Bama tune on XCal 3000 (me)
Mods that should not affect problem:
- 3 90mm Metco idlers to replace the stock ones (me)
- MGW shifter (guy before me)
- Raxiom blacked out taillights (me)
- Sequential tail light kit (me)
- Hub centric spacers on rear wheels (guy before me)
I had previously datalogged my car and it seemed to be running rich but I was fine with that since it's better to be safe than sorry. I recently emailed Bama that I would like to datalog the tune and told them I think it is running rich and it hesitates on shifts (attached the links mentioned previously). They were very nice and told me what params to datalog and to get back to them. So now I am just waiting until I get a good chance to datalog it.
Also, I am located in Texas where summers can get hot! The car has been autocrossed 3 times and never had issues. Aside from the occational 1st or 2nd gear pull, I am easy on the car and it never goes on top speed highway runs or anything like that.
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Delete the PPRV and call it a day. Never had a single problem ever since i deleted mine.
You dont "have" to turn the key to prime the pumps, you can crank the car as normal and it will start, it just takes a few more cranks to let the fuel work its way back up to start the car. I do how ever turn my key first to let the pumps prime, then start the car. This is what the PPRV does from the factory, it holds the fuel pressure between shutting the car off and starting it again so you dont have to let it sit there and crank. This is the only inconvience of doing the PPRV delete, but IMO it is well worth it.
You dont "have" to turn the key to prime the pumps, you can crank the car as normal and it will start, it just takes a few more cranks to let the fuel work its way back up to start the car. I do how ever turn my key first to let the pumps prime, then start the car. This is what the PPRV does from the factory, it holds the fuel pressure between shutting the car off and starting it again so you dont have to let it sit there and crank. This is the only inconvience of doing the PPRV delete, but IMO it is well worth it.
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My car does this as well. Stock fuel system and 2.79 pulley and tune with basic bolt ons. It pulls power hard between shifts. I emailed my tuner about it and will see what he says. Thanks for the info folks.
I see acouple things in your list of mods that could be cause..
I had nothing but issues with mil elimators..
I have all 4 o2s on with predator performance tune..
intercooler pump not working is major...this pulls timing...bad
I would do compression test to see if all 8 cylinders are good..leakdown test is better if you see issue..
ive had valve issues 2 times and 1 time crack in cyl..
these will run on 7 cylinders. ..
I valve issue will not give misfire code
What part of texas...im south of san antiono
all 3 times issue found on basic compression test..
abs light...could be anything from alt to dirty wheels .
mixed match wheels..
I had nothing but issues with mil elimators..
I have all 4 o2s on with predator performance tune..
intercooler pump not working is major...this pulls timing...bad
I would do compression test to see if all 8 cylinders are good..leakdown test is better if you see issue..
ive had valve issues 2 times and 1 time crack in cyl..
these will run on 7 cylinders. ..
I valve issue will not give misfire code
What part of texas...im south of san antiono
all 3 times issue found on basic compression test..
abs light...could be anything from alt to dirty wheels .
mixed match wheels..
The intercooler pump works fine now. It seems like it had wiggled its way unplugged. I do not really have a need for the MIL Eliminators as I put them on before the car got a tune. The car still pulls very hard and runs great so it does not seem like it would be running on 7 cylinders. I am in the Waco area.
All wheels are stock with 275 nitto motivos on them. From the reading I have done it seems that the ABS module is going out as it can be on at any speed, not just when the car is moving.
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Yeah. Just sent a datalog to Bama to get a new tune. It only has the issue if I don't get wheel spin in the top end of 1st gear and I couldn't get a solid pull for some reason today (tried 5-6 times). I think them refining the tune from the datalog will still fix the problem, although I may have to send another when it actually happens.
Have you tried with out spacers on rear wheels for abs?
There is a recent thread on jlt with maf location...
I got over a year seat time in mine...360,000 miles..
coils can be issue...finding a member close to swap out for testing is how I found my coil issue..they get weak..no code..
what plugs are in it....
I run oem fine wire#12s...
The spacers have been on since I got the car and I have never had the light come on until a few days ago so I really doubt that is the issue. And I will look more into coils or maf or whatever if the tune does not work! I honestly have no idea what plugs are in it... never checked lol
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