its not the egr

[blktyphoon]

the mechanics couldnt find anything wrong with the car. they ran diagnostics and nothing unusual. they test drove it and sure enough it didnt die out. so i went to pick it up and it ran fine all day. the next day too. today it started again, it dies out i wait a few minutes then it starts. i drive a block it dies out again and blows a code, a 34. its something with the mapsensor does any one know how to troouble shoot this. would a bad map sensor do this. would the car even start and run with a bad map sensor. i need help i want to help my truck i love it soo much.

 

[ViciousV6]

Re: its not the egr

the mechanics couldnt find anything wrong with the car. they ran diagnostics and nothing unusual. they test drove it and sure enough it didnt die out. so i went to pick it up and it ran fine all day. the next day too. today it started again, it dies out i wait a few minutes then it starts. i drive a block it dies out again and blows a code, a 34. its something with the mapsensor does any one know how to troouble shoot this. would a bad map sensor do this. would the car even start and run with a bad map sensor. i need help i want to help my truck i love it soo much.

Have you checked the fuel filter, and if you have a adj fuel press regulator check to make sure your not sucking some fuel up in the vac lines from the regulator. The rubbers go bad in regulator and leak into the vac lines causing the map to malfuction.

Of course if you have vac leak will cause the map to get false readings.

What is done to the truck, stock, modified.

Ralph
ViciousV6

 

[blktyphoon]

Re: its not the egr

Have you checked the fuel filter, and if you have a adj fuel press regulator check to make sure your not sucking some fuel up in the vac lines from the regulator. The rubbers go bad in regulator and leak into the vac lines causing the map to malfuction.

Of course if you have vac leak will cause the map to get false readings.

What is done to the truck, stock, modified.

Ralph
ViciousV6

its got a walbro thats about it.i have an adjustable fuel press reg but i havent put it in yet. the car still runs when i let it sit for a while

 

[91blazins10]

Re: its not the egr

code 34-This will set when the signal voltage from the MAP sensor is too low. Instead the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery. Replace the MAP sensor.

id just get a new one.

 

[blktyphoon]

Re: its not the egr

code 34-This will set when the signal voltage from the MAP sensor is too low. Instead the ECM will substitute a fixed MAP value and use the TPS to control fuel delivery. Replace the MAP sensor.

id just get a new one.

would this cause the car to die out though, what would cause the car to not start for a couple mins thats what it doin, the car will stay runnin if i keep the rpms up let me pick your brain

 

[91blazins10]

Re: its not the egr

would this cause the car to die out though, what would cause the car to not start for a couple mins thats what it doin, the car will stay runnin if i keep the rpms up let me pick your brain

if the ecm is using the tps to control fuel delivery then yea it prob might make it die, because when your keeping those rpms up it sees that and is adding fuel and that keeps it running.

 

[ViciousV6]

Re: its not the egr

would this cause the car to die out though, what would cause the car to not start for a couple mins thats what it doin, the car will stay runnin if i keep the rpms up let me pick your brain

Well if your stepping on the gas right it is changing the computer calibration and keeping it running. Yea alot of our sensor use each other to stay running correctly. When was the gas filtered changed and if you don't have a fuel pres gauge i would strongly reccommend to get one. If the walbro is old it shouldn't be over looked. Keep an open mind what the computer is saying may just be a result of something else having a problem.

When does it do it after driving, short, long distances, Sitting idling, only intermittent evey couple days. I have a few 2 and 3 bar maps laying around if you wanna try that out or see if you can get from your local GM dealer.

Ralph
ViciousV6

 

[blktyphoon]

Re: its not the egr

if the ecm is using the tps to control fuel delivery then yea it prob might make it die, because when your keeping those rpms up it sees that and is adding fuel and that keeps it running.

but after it dies it wont start for 15 or 30 mins why do you think that is? wouldnt it still start at least

 

[ViciousV6]

Re: its not the egr

but after it dies it wont start for 15 or 30 mins why do you think that is? wouldnt it still start at least

That was one of the problems this guy had in my area the truck wouldn't start and then it would start because the pump was going in and out. I figured it out by putting a fuel pres gauge on the rail and saw the pres drop after the truck started and then listened in the tank and heard the pump press or sound drop off. Now you are popping up a code so if the computer is not clearing that code it may take 15-20 mins for the volts to correct and then it will start. You could always pull the ecmb fuse right after it happens clears ecm and then see if it will start right up. Then untill it trips it again you will be fine. Like i said i have seen issue while runnning with my silverado with the fuel filter gets clogged and cuts off the fuel press too, of course is why i have fuel press gauge so i can see any press drops.

Hope this helps
Ralph
ViciousV6

 

[TYTILIDIE]

Re: its not the egr

Did you get htat FP gauge like I said? Youre really putting yourself in a bad situation here. You probably couldve had it figured out by now. When hte CEL comes on, and its the code 34, the truck start to running all messed when you can keep it running? And is this while the CEL is on?

 

[dgoodhue]

Re: its not the egr

I haven't followed these thread's, sorry if this has been brought up before.

How are the vacuum lines going to the MAP & FPR?