MAP sensor problems and more

[der affe]

so here is the chain of events........

2 weeks ago, my fuel pump died on the way home, on the freeway. i jumped off and limped it the short distance home and did a fuel pressure test as it would idle and not let it rev without stalling out. tests showed that the fuel pump was on it's last legs. not bad for 300km on a 1991 as i am pretty sure it was orginal.

i ordered a 255lph pump from TRE performance and installed it the following Saturday. it fired up and ran great! 2 days later i took it out for a drive late at night. i drove it about 5 miles and just as i was turning onto my street i got pulled over for my licence plate lights being too dim . that took about 10 min. for him to let me go without a ticket. then the car would not stay running under load.

the next day, i started digging into it and found out the #1 and #6 coil pack was weak or non existent. i swapped it out for an extra coil pack i had and #1 cyl came back, but #6 was still dead.

i did an ohm check on the wires and found out that #6 wire had 30.74 ohms of resistance. next, i made a new replacement and #6 came back online.

i also removed and cleaned the LC-1 wide band o2 sensor with oven cleaner and flushed it with brake cleaner and recalibrated it.

when i restarted the car, it would not stay running and just pressurize and and fire then die.

i eventually got it to fire and run with a lot of cranking and feathering. next i started chaising that problem. i was getting a huge MAP reading of 85 kpa (normally i get around 65 kpa). i reached up and checked the MAP sensor vacuume line and when i moved it to check the line, the idle suddenly smoothed out and i was getting a MAP signal of 68 kpa. it was getting late so i will deal with it tomarrow.

my questions is: if i was getting a weak MAP signal by the line not being connected correctly, why was i getting MAP readings in the 80-100 kpa range. shoudn't i get a low reading froma bad connection???? the collar that goes over the MAP sensor at the ECU was slightly loose, but the vacuume line was completely seated.

so far it starts up and runs fine, but i have not done a test drive yet as it was getting late.

just tring to get some insite so i can be sure that it is fixed.

[nando]

maybe it'd come partially disconnected? normally MS isn't really that sensitive to vac leaks, but in an odd circumstance it could have been something like that.

otherwise check the calibration of the sensor. I think it's the MPXH6400 (4 bar sensor).

to be honest, I never really loved that sensor. if it turns out it's gone bad, I've got a couple spare 2 bar sensors, I'd give you one to replace the 4 bar. I wouldn't expect it to go bad, but you never know. with it calibrated you should see ambient pressure with the engine not running - about 100kpa depending on your altitude.

[der affe]

so, with the ignition on, but not running i should be seeing around 100 kpa?

eight now with the ignition on, but not running, i am seeing between 22 and 27 kpa. it then jumps to around 70 kpa with it running normally.

in this one instance, it was getting a reading from 80 to 100 kpa with it running and 30 to 32 kpa with it off after running.

does that sound out of range?

how do i set the range of the sensor in the ms? i don't remember seeing that in the sensors table.

•The elevation of Scottsdale, AZ is 1,248 feet, measured at the Civic Center

•The elevation of Paradise Valley, AZ is 1,343 feet, measured at the Town Manager Office

i am inbetween both, but there is not a huge difference in elevation between the 2

[nando]

yeah, that's not right.

even if you were at a high elevation, and you're really not, it wouldn't really go much lower than ~80kpa ambient. I'd expect at ~1200 feet to see pretty close to 100kpa. you're only 900 feet higher than me!

you can recalibrate it under the tools menu. If that doesn't work I can mail you one asap.

[der affe]

I tightened down the collar and that seemed to fix it, but i think i will go ahead and replace it.

As far as the MAP reading goes, when i got it running, everyone seemed to think that a reading of 70 was pretty good for having ITBs and a 292° cam.

What do you think?

AND........they are putting a new roof on my house and i backed up over a roofing nail they missed and i now have a hole in my tyre.




FUCK!