Sorry,I don't know how I did this.This is from a different thread
Fuel Pressure under boost
- Thread starter Sinisturbo
- Start date
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Sorry,I don't know how I did this.This is from a different thread
I wouldn't just go out and buy one. I'd remove the one you have and blow through it first. Then decide
.
Here's what you said.
How did you determine that his regulator and fuel pump were bad?
He already has a gauge.
He has a fuel pressure problem that he needs help with and you offered that he might need a chip and injectors.
How did his observed fuel pressure lead you to think his MAF might be bad?
He's definitely got an old pump. Let's look at some other things first. He's definitely got an old pump.
Buying a scanmaster won't do crap to diagnose this condition. The update is too slow. Visually seeing a gauge that confirms the pressure isn't rising 1:1 will lead you to a voltage problem, bad pump, leakage in the tank, or kinked/clogged lines or filter. From there you can create your own flow chart and check the easiest things first. My guess is the pump is the problem. Idc if it was replaced yesterday. Its obviously not a pressure problem but a pressure/volume problem
So from chatting with you the word " Upgrade " means "bad" and the statement "could be" means deffently. Now I see what I am dealing with. For the third and final time I was giving him an example of how important a ScanMaster is, that's all. I know the MAF has nothing to do with fuel pressure. Do you understand now what I was trying to say. As I stated before low fuel pressure = low voltage, restriction or old parts going out. Let me ask you a question when someone buys a stock TB and wants to mod or upgrade what's the first area you would concentrate on, for me it's the fuel system. This is where the pump, adjustable FP regulator, hot wire kit and injectors come in.
Brian so I understand this right if the FP doesn't go up 1:1 with boost, replacing the filter doesn't fix the problem and no restrictions are found then the next step would be to check to see if there is a voltage drop,correct ? So why would a ScanMaster be useless in this situation. I am not doubting you I just want to understand why. Also if there was a vacuum leak couldnt that be a cause of this issue and wouldnt that show up in the form of high BLM. Again I am not doubting you I just want to learn why.Thanks, Kyle.
scanmaster doesnt see the alternator output voltage unless the wiring to the ECM has been upgraded. Small leak might show up as a slight increase in blm but verifying 1:1 increase is most important since wot fueling will be less if not a 1:1 increase. I'd check for alternator voltage at the pump. Even 12-13v would be fine for this nearly stock car. I've seen cars with 10v at the pump when the alt was charging at 14v and scanmaster showing 12.8. The important ones are the alt output and the voltage the pump sees. Notikle said:
What the scanmaster displays.
The bottom line is that the only voltage we need to know about is the voltage at the pump. As you say,because this car is stock,a voltage of 10-11 would probably be good enough. This car has a serious pressure rise problem. At its stock level,a couple of volts wouldn't have this much effect. Besides,they all have lower than system voltage if they're not hotwired. If his filter checks out,he probably has a bad pump. Heck,because his pump is original it's probably bad.
Ok, thanks for your explanation, I thought whatever voltage the Scanmaster was reading is what the voltage at the alternator was, makes sense. Learning more and more every day. Thanks, Kyle
I agree 100%, Sorry for getting so defensive. Kyle
We all do it. You're forgiven.
Sinisturbo
Maximum Entropy
- Joined
- Jun 10, 2011
- Messages
- 31
Well replaced the fuel filter that helped some, I hot wired the pump and now I am right at 50 with 10 lbs of boost.
I have the scan master hooked up and my numbers at idle are see below, i replaced the o2 sensor but still have mal code 44 and low O2 numbers.
If I turn the car off and wait 5 minutes, start the car the O2 reads 400 and the int and bl are 128. But the O2 goes down and the int and bl go up to 150.
I am going to look for vacum and exhaust leaks tonight.
AF 05
L8 24
BAT 13.6
INT 150
LB 150
CLT 198
ATS 125
R 875
TPS .44
IAC 00
MAL CODE 44
O2 100
I have the scan master hooked up and my numbers at idle are see below, i replaced the o2 sensor but still have mal code 44 and low O2 numbers.
If I turn the car off and wait 5 minutes, start the car the O2 reads 400 and the int and bl are 128. But the O2 goes down and the int and bl go up to 150.
I am going to look for vacum and exhaust leaks tonight.
AF 05
L8 24
BAT 13.6
INT 150
LB 150
CLT 198
ATS 125
R 875
TPS .44
IAC 00
MAL CODE 44
O2 100
Did you check the voltage at the pump,before you installed the hot wire?
Your high BL and your low IAC tell me you have a vacuum leak.
You don't have to look for exhaust leaks,you listen for them.
You have a substantial vacuum leak.
Sinisturbo
Maximum Entropy
- Joined
- Jun 10, 2011
- Messages
- 31
You have a substantial vacuum leak.[/quote]
TType hit it on the head, My vacum booster is defective. I blocked off the vacum line to the booster and all is good.
O2 480 Idle
Af 05
L8 35
Batt 13.7
Int 133
Bl 140
clt 203
Ats 93
R 675
Tps .41
Iac 21
no codes
TType hit it on the head, My vacum booster is defective. I blocked off the vacum line to the booster and all is good.
O2 480 Idle
Af 05
L8 35
Batt 13.7
Int 133
Bl 140
clt 203
Ats 93
R 675
Tps .41
Iac 21
no codes
TType hit it on the head, My vacum booster is defective. I blocked off the vacum line to the booster and all is good.
O2 480 Idle
Af 05
L8 35
Batt 13.7
Int 133
Bl 140
clt 203
Ats 93
R 675
Tps .41
Iac 21
no codes[/quote]
Holy cow,now you have to contend with a car that runs right. I'll have to see if they sell a sympathy card for that predicament.
I'm assuming that you checked all lines.
