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zukiracer19
11-23-2008, 09:15 AM
ok I purchased a check valve for my map sensor(same one i have on my hvac) cuz the one i got from todd vaccum side doesnt leak but map side does.... cuz the hole is so small and 3 zip ties still dont cut it... i put a different check valve on it... car shuts off after like 10 mins of driving... than i put the old on back on(still leaks a little) drives but idles funny(due to vaccum leak). so i taped around it to make it thicker. than zip tied it... pretty sure it stopped most of leak if all of it... but now car shuts off again and will not idle... any suggestions?? i took tape off and put 3 zip ties on it again and it runs ??? i don't get it?

AaronGTR
11-23-2008, 09:57 AM
Why are you putting a check valve on the MAP sensor? There is no need for it. All you need is one piece of rubber tube between the UIM and the MAP sensor and a couple hose clamps, and that should be enough to not have any leaks.

fyi, the check valve is probably what is causing your problem. Air needs to be able to move freely back and forth in the tube as pressure changes in the UIM so that the MAP sensor can read it. If you put a check valve that stops air from moving in one direction, it is going to hold pressure and the MAP sensor will be sending a signal to the PCM that does not match what the engine is seeing. That's going to cause it to run poorly and eventually stall.

Shock24Z
11-23-2008, 10:18 AM
Why are you putting a check valve on the MAP sensor? There is no need for it.

X2


You have a Powrtuner. Scan for MAP values.

KhellendrosxS
11-23-2008, 10:21 AM
IIRC Todd was having problems with MAP sensors going bad when seeing high boost levels. He put in the check valve because it does no good once the car is boosting because it cant read the boost. I guess his rational was why bother subjecting it to those conditions when it wont read them.

The check valve as I understood his setup was to open as soon as boost dropped below atmospheric pressure (WOT, non boosted/ 0inhg) and was to close as soon as boost was detected thus allowing it to function in vaccum as normal while closing it off and preventing damage from high boost levels.

Id just try what Aaron suggests and just run a straigt tube to the UIM for now. You havent got the transmission Todd was working with when he was bashing it and Im betting your trans would go bad before the MAP sensor.

zukiracer19
11-23-2008, 10:28 AM
so just remove check valve, let it go ? idk he told me to check valve it... and my boost is spiking from 6 to 7... could it be because of the leak?? i tried turning it to 7 but it wants to stay at 6...

AleroB888
11-23-2008, 10:57 AM
so just remove check valve, let it go ? idk he told me to check valve it... and my boost is spiking from 6 to 7... could it be because of the leak?? i tried turning it to 7 but it wants to stay at 6...

I have not had a problem with a MAP sensor failing, going on 5 years now.

You need to be scanning this stuff....

zukiracer19
11-23-2008, 11:04 AM
i was scanning, my gf said she'll bring the laptop over again... it just STARTED doing this... i got another map sensor, but does it need to be check valved or not?

AleroB888
11-23-2008, 11:15 AM
i was scanning, my gf said she'll bring the laptop over again... it just STARTED doing this... i got another map sensor, but does it need to be check valved or not?

No, in my opinion. Keep in mind also that if the car runs for a length of time with a problem like a vacuum leak, the PCM will try to adjust for it, then when the problem is corrected, the car may still not run right for some time...

You should reset the fuel trims after the problem is corrected.

AaronGTR
11-24-2008, 09:31 PM
^I agree... no check valve. 5+ years for me with boost as well and no problems. And yeah, reset the fuel trims once you have the problem sorted out.