Cel P0170&P0172 coming on & off

[Rohan]

Originally Posted By: Vikas
Remove the fuse and start the car until it dies.


Thanks.

 

[Rohan]

Before I'm taking of the FPR i first took of the vacuum line that's on the FPR. It turned out to be crack vacuum hose so I put in new vacuum hose and see if it holding the pressure and it did hold the pressure. After this I crank up the car and clear the code. Let see if it come back or not.

 

[Vikas]

I hope you did not pre-order the FPR :-( Most likely the cracked vacuum hose was your problem.

 

[Rohan]

Am I supposed to test the FPR when engine is cold or after engine is warm? When I did the cold test result came out no pressure lost, but after I shut off the engine then do the FPR pressures test again then the result came out pressures is leaking. Again this is after I turn off the engine.

 

[Rohan]

Originally Posted By: Vikas
I hope you did not pre-order the FPR :-( Most likely the cracked vacuum hose was your problem.


I have new FPR with me.

 

[Vikas]

Well, replace the hose and see if the problem goes away.

I am not understanding where exactly you are measuring the vacuum. Do you have a vacuum gauge which also has vacuum pump?

If you are hooking up the pump to the FPR, it should hold vacuum regardless of the engine temperature.

 

[Rohan]

Yes, I have vacuum guage that came with the vacuum pump and I already replaced the hose. I'm saying after I shutdown the engine from idling for 10 minutes then do the test again I'm loosing the pressure. If I do the test again when the engine is completely cold (not running or crank) then I'm not loosing any pressure.

So you are saying with the engine off after idling it supposed hold the pressure. Correct?

 

[Vikas]

Assuming you are talking about FPR and assuming it has single vacuum hose and rest are metal pipe carrying fuel, then the vacuum hose ends at the diaphragm inside FPR, it should hold vacuum regardless of the temperature of the FPR.

After putting the new vacuum hose, have you got the code back again? Drive the van for few days before deciding to put the new shiny FPR in.

Also let us keep the nomenclature correct to avoid confusion. You are measuring if the vacuum can be kept by FPR when you "pump" vacuum in to it.

Conversely, one can also measure "pressure" of the fuel rail. It should hold the pressure after you turn off the car, at least for a while. If the fuel pressure bleeds off, you might have hard starting problem on cold start. As far as I know you don't have fuel pressure gauge.

 

[Rohan]

Okay here's what i got. Cel came back on today P0170&P0172 after I did put the new vacuum hose. I did look at the ob2 showing that short tirm fuel moving up and down all the time and the number I was getting it was -15.00 between-22.00. The long tirm fuel stay in one place as while engine temperature changing then long trim fuel change but it stay at 1 number not moving up & down like short fuel trim doing.

I did take off the vacuum hose on the FPR while engine is idling and I did not see any fuel coming out from the FPR hole.

I do not have fuel pressure gauge. Even that don't I need to buy special fitting for guage fitting on this Honda?

 

[Rohan]

Yes I'm pumping the vacuum pump into the FPR with the hose on and it barely leaking not fast after I turn off the engine then I do this test. I don't know why I don't have cold start problems.

 

[Rohan]

I forgot to add that long trim fuel is also reading higher number like -16.00 or so.

 

[Vikas]

Looks like you should replace the FPR then.

What is the freeze frame data when you get P0172?

When you look at fuel trim data, you should add LT and ST in your head. It is the total that matters. If the total goes under -25 or over +25 (around that numbers) computer throws the code.

I do not know if the Honda need special gauge fitting

 

[Rohan]

Originally Posted By: Vikas
Looks like you should replace the FPR then.

What is the freeze frame data when you get P0172?

When you look at fuel trim data, you should add LT and ST in your head. It is the total that matters. If the total goes under -25 or over +25 (around that numbers) computer throws the code.

I do not know if the Honda need special gauge fitting


I'm going to go ahead replace the FPR, clean the throttle body, and replace the air filter.

I know this might be stupid to ask how can I get freeze frame data?

I didn't know that I need to added LT and ST number together if that's the case then by adding up them together come up to -25 as far I remember.

Im sorry I was talking about Honda adapted fuel gauge.

I'm going to change it on next Tuesday which is my day off.

@Vikas I really really appreciate that you are helping me out.

 

[Vikas]

If you give me URL of your code reader, I might be able to find if it reports freeze frame data. Not all code reader do that. You keep on saying "ob2" but I need user manual for your hardware/software/app combo.

 

[Rohan]

If you give me URL of your code reader, I might be able to find if it reports freeze frame data. Not all code reader do that. You keep on saying "ob2" but I need user manual for your hardware/software/app combo. [/quote

Let me look.

 

[Rohan]

okay need your help on where can I find the URL?

 

[Rohan]

Okay this is where I got it from.

http://www.amazon.com/gp/aw/d/B00W0SDLRY...&ref=plSrch

 

[Vikas]

That is the hardware device aka ELM via WiFi. What app do you run? Do you have URL for that app? I wond4er if you are supposed to buy another app to get all the functionality.

 

[Rohan]

Originally Posted By: Vikas
That is the hardware device aka ELM via WiFi. What app do you run? Do you have URL for that app? I wond4er if you are supposed to buy another app to get all the functionality.


I have obdcardoctor app. The other app that might work with my device is dash command app.

 

[Vikas]

Register at their website and ask in their forum on how to get "freeze frame data" using their app. While there ask if there is a way to get Mode $6 data too.