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A friend called me to have me help him try and figure out what is going on with his car, he has APS TT running around 10psi (~400whp), he has had no issues until recently he drove into a rather large puddle and then his car started acting up. Also, to cloud the issue he was also rear-ended shortly after the issue started but he assures me that the issue started before the collision.
The car is driving 100% fine under vaccuum (starts and idles fine and has solid fuel pressure of 40lbs on 650cc injectors) but as soon as boost starts to come in the car bogs and dies, after connecting the laptop you can clearly see that as soon as 1psi of boost is hit (3000ish rpm) his injector pulse rises to 22ms and his duty cycle is hitting 64% ... there is a very strong smell of gas if he doesn't lift.
Anyone have a clue?
Could this just be a simple boost leak ???
__________________ Proud developer of Forza Motorsport 4 --- IP G35 Coupe [557rwhp 563rwtq 17.5psi]
What is the utec crossover? If it is 1psi then it cant be the MAF because Utec should be in Open Loop. If it is the MAF then your problem should be in vacuum. Are you using the manifold as a boost reference for the utec map sensor? If so then it may not be a boost leak because you are reading from the manifold already. Make sure you are in the right switch/map in utec. Hitting that puddle might have cause the Utec to switch to a different map. Please post some logs since you have a utec. what load/cell in the map are you hitting at 1psi?
the car sputtered once right before the accident, but at the same time I had low oil and the vehicle tripped a cam sensor light because of it. Therefore, I'm not positive if it was due to the hit or due to the puddle that I am having the issues that I am now. It goes into the shop tomorrow, but I was hoping to have some answers for them. Learned my lesson about the oil, and changed it the next day...but this issue still remains
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not the fastest on the streets, not the prettiest in the shows, but still a nice car
Long shot but I have heard the crimped rubber tubes can collapse sometimes on the intake portion of the aps kit. Prolly not the issue if it starts happening at 1psi though...
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Stock Block DE Vortech 418RWHP 355RWTQ
What is the utec crossover? If it is 1psi then it cant be the MAF because Utec should be in Open Loop. If it is the MAF then your problem should be in vacuum. Are you using the manifold as a boost reference for the utec map sensor? If so then it may not be a boost leak because you are reading from the manifold already. Make sure you are in the right switch/map in utec. Hitting that puddle might have cause the Utec to switch to a different map. Please post some logs since you have a utec. what load/cell in the map are you hitting at 1psi?
I'd have go to round his house and do some logging but this is what I remember. Crossover is 3psi, boost is from manifold, utec was definately using map 1, sorry about the brevety of this reply, sent from iPhone.
__________________ Proud developer of Forza Motorsport 4 --- IP G35 Coupe [557rwhp 563rwtq 17.5psi]
Based on the hp level I assumed he was using a stock MAF sensor. Would he by chance using a MAP sensor with an EMS? If so, which EMS?
UTEC supports external MAP sensor. He can use this as reference load value. I believe that he has already a MAP sensor installed, that's why he can use switching based on Manifold Pressure.
As for the problem, I believe that it is a UTEC problem. Impact could damage an EPROM inside the CPU. Casing can short circuit some of the contacts inside the CPU. I had a similar case my self. Just take out UTEC, lie it on the floor of the car with the ground in place, and see what happens.
If you are throwing cam sensor codes that is most likely your issue. I've seen it sometimes when these sensors go everything seems fine until boost. I highly doubt the UTEC spontaneously changed maps.
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2004 G35 | Stock Block | Twin GT25R | Best ET 11.8@120
cam light hasn't came back since oil change...was just low on oil for that to trip. It goes to a local shop today to see if they can figure it out. The other drivers insurance will be picking up the tab for it too as long as they can prove (or at least argue the point well) that it was accident related.
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not the fastest on the streets, not the prettiest in the shows, but still a nice car
I'm assuming that the MAP sensor is reading OK, is this correct? Make sure it is and that the Utech is getting the signal. Also, make sure all of the connectors are dry. Water will conduct electricity (unless is distilled water), and could be throwing off some of the sensor readings the Utech is relying on.
cam light hasn't came back since oil change...was just low on oil for that to trip. It goes to a local shop today to see if they can figure it out. The other drivers insurance will be picking up the tab for it too as long as they can prove (or at least argue the point well) that it was accident related.
Why would a cam sensor trip a CEL if you were low on oil? The cam sensor has no idea how much oil you have in the car and it doesn't care, all it does is monitor cam position.
I'm assuming that the MAP sensor is reading OK, is this correct? Make sure it is and that the Utech is getting the signal. Also, make sure all of the connectors are dry. Water will conduct electricity (unless is distilled water), and could be throwing off some of the sensor readings the Utech is relying on.
The MAP was reading fine, -9lbs at idle and progressed to 1lb at which point fuel would be dumped ...
My gut feeling is that something got wet somewhere ...
__________________ Proud developer of Forza Motorsport 4 --- IP G35 Coupe [557rwhp 563rwtq 17.5psi]
Need help virtually diagnosing ...
