Sure sounds like a pegged maf or dirty maf to me.:shrug:
Hits limiter at 4700-5500????
- Thread starter CanuckSnake
- Start date
I guess you didn't notice my post where i said i had the same problem, and it was the M.A.F.. (mass airflow sensor)
If you have a tuner that knows what hes doing it will be an easy fix, and it will be well worth the money to take your car to the top of the gears,
Good luck hope they figure it out.
Question, just going to throw this out thier. Those saying that it could be the MAF....Now, I had recently cleaned my MAF with CRC MAF cleaner, cleaned the filter too. I havent changed altitude, temps havent changed much, why would the settings or something with the tune change? How can the tuner fix it, nothing was changed? It just randomly has the problem. Some it is all the time, some is hit and miss. Could it be the MAF starting to go bad? What would cause that?
Here is another possible scenario....What about the boost valve in the blower? I believe it is located in the rear, could this be getting stuck? loosing vacume? I only suggest this as a possible prob becuase my car was doing this like clock work the whole day all day, floor it...get to 5,200 rpm and bam, falls flat. I pop the hood disconect the vacume line to the valve in the blower, apply some suction, then pressure, suction, then pressure again to free it up in case it may be sticking. Then I get in the car, take it for a spin and it is fine!!! Not sure how long it will last, but I have heard of them sticking and other probs with the Whipple valve. I am thinking that the next time it happens to me I am going to remove the Whipple and check it out.
James
Here is another possible scenario....What about the boost valve in the blower? I believe it is located in the rear, could this be getting stuck? loosing vacume? I only suggest this as a possible prob becuase my car was doing this like clock work the whole day all day, floor it...get to 5,200 rpm and bam, falls flat. I pop the hood disconect the vacume line to the valve in the blower, apply some suction, then pressure, suction, then pressure again to free it up in case it may be sticking. Then I get in the car, take it for a spin and it is fine!!! Not sure how long it will last, but I have heard of them sticking and other probs with the Whipple valve. I am thinking that the next time it happens to me I am going to remove the Whipple and check it out.
James
I don't think it has to do with boost becaue when it's on the so called limiter the boost stays right at 15-17, but thanks for the suggestions.
I put a fuel pressure gauge on it today and taped it to the wiper and went for a drive. 32-37 during cruise, aroung 40psi at WOT untill it hits the issue at around 5000rpm and goes up to 60psi. I'm guessing because the car is still telling the fuel pumps to giver but the injectors arn't opening. I get out of the fuel and it goes back to around 35. Does 40 psi at WOT sound right or should it be higher, question to those guys with fuel pressure gauges. I'm still thinking the issue is with the tune and the MASS sensor. It has a Diablo adjustable thingy inline with the MASS but I'm afraid to mess with it, its on 3 right now.
Mine was doing somthing similar at the track this weekend. At the top of third it would just fall flat on its face. Then on the next run it did it at the top of 2nd and third. I thought I hit the rev limiter but I noticed my shift light never came on. I also seen my fuel pump DC hit 100 through the aeroforce gauge trying to trouble shoot it on the way home.
I didnt think that with 580 RWHP and 15 PSI that I would be maxing out my fuel system with the stock pumps and a BAP. I also have a SCT BA2400 MAF. Maybe one of my pumps are bad.
I didnt think that with 580 RWHP and 15 PSI that I would be maxing out my fuel system with the stock pumps and a BAP. I also have a SCT BA2400 MAF. Maybe one of my pumps are bad.
40psi at WOT is correct with these cars so ive been told and noticed on the dyno
Well those of you who guessed fuel problem win! I dropped the tank today and found a small cut on one of the hoses coming off on of the pumps where it was rubbing on a sharp piece of metal. Put in a new piece of rubber hose and she's back to pulling like a rapped ape! I guess it was enough fuel pressure to keep the psi gauge high but just not enough volume.
My new Cobra does the EXACT same thing! I have only had her for 2 days. Super annoying to say the least. I am going to pull the PPRV thing soon and replace all the lines while I am there. Hope for the best.
I have a similar issue and almost exact symptoms and most agreed that I had a fuel problem. Mine I will solve with just going with a return fuel system like I had always planned.
Glad to hear you figured it out and once again I love this forum!!these guys are spot on!:bowdown:
http://www.svtperformance.com/forum...3-4-whipple-falls-its-face-tr6ix-plugs-2.html
Last week I did as I described...deleted the PPRV, added a -8 fuel line up to stock rails, added a new SCT 2600 MAF and retuned the car. Everything has been perfect till today. (roughly a week later)
Problem: 1st gear runs to 6500-7000rpm fine. 2nd and 3rd seem to just shut down (exactly like rev limiter) as described. Fuel pressure gauge shows strong PSI the whole time. Should I drop the tank and check the PPRV delete hoses? Maybe just add a set of pumps while I am there? What do you all think?
I have the same issue with my car. I dropped the tank today and checked the hoses and clamps to the pumps...they appeared fine. I R&R the FRPS...that didn't help. I swapped out the FPDM...no help there either. Dropped the MAF and filter for a cleaning...nothing. I'm at a total loss for ideas at this point. Currently I can't data log but will soon enough when my Aeroforce gauge gets here. Any other suggestions???
I will be datalogging this week then. Are you running an air/fuel gauge? I drove her to the gym today and noticed that the AF was in the 13's (wot) and if I remember the af all last week was in the 11's. Maybe I/we have a pump going bad?
IS there any way that a bad or faulty crank position sensor might cause all, or some of the above? When I got my car tuned for the last time, as I was pulling out of the bay my SES light came on. We pulled the code and it had something to do with a crank position signal (can't remember the exact code.) Anyhow, on the way home my motor would cut out intermitently as if the fuel pump was being turned off and on. It also acted like there was a wicked short in one of the wires. Anyhow, I just bought a new crank positon sensor to try. What all is involved in R&R it?
It's fixed!!
Turns out my SCT flip chip was not set in on the ECM board correctly:fm: Pulled it out, set it back in correctly, and she runs like a top again. Just to prove to myself this wasn't some fluke thing, I ran the piss out of it for about 1/4 tank of fuel.:beer:
Turns out my SCT flip chip was not set in on the ECM board correctly:fm: Pulled it out, set it back in correctly, and she runs like a top again. Just to prove to myself this wasn't some fluke thing, I ran the piss out of it for about 1/4 tank of fuel.:beer:
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