ok here are the readings
engine off for over 24 hours
iat 37
ect 37
map sensor reads 14.5
and I don't know if it makes a difference when the front o2 sensors are reading when engine off but here they are tooo


b1s1 .195
b2s1 .145

 

Gotta know what the ambient temp was, and trans fluid temp would be helpful too. What this test does is to prove ECT and IAT are the same, and equal to ambient temperature. Everybody needs to be on the same page

 

yes it was about 34F outside. and the truck was in the garage. so 37f on the sensors seems about right. thanks. just wanting to get this thing fixed.

sorry I forgot to mention outside temp. outside temp was about 34F


so whats next. what should I check next. I'm stumped right now. thanks again.

 

I can walk you through this but, "ball park" answers and guesses are not going to work.
Bring the engine up to operating temperature, (~200F). Connect the scan tool. All accessories off, trans in park or neutral, engine at idle, (throttle closed), PCM in closed loop operation. Post all live data, rpm, tps, maf, map, ect, iat, fuel trims, oxygen sensors, everything that the scan tool shows, post it.


Will also need all 4 readings for fuel pressure and leakdown: https://blazerforum.com/forum/2nd-ge...eakdown-88305/

 

ok will do... thanks man.

 

ok heres all the live data at idle.




I will try and get the fuel pressure readings tomorrow.

 

Where exactly is the exhaust leak(s)?

 

right in front of the cat. it was glowing red hot so I thought it was plugged up. so I cut it right in front of it. going to have a new cat put on after I fix it.

 

ok here are the new fuel pressure readings with new injectors.


fuel pump jumped to 12v is 60psi and as soon as I take 12v away it drops instantly to 50psi and holds for over 10 min


readings after the fuel filter are 92psi then 72 psi after 10 min


the new injectors are reading a bit lower than the old ones.
I might have to pop the plenum off again and adjust the regulator up to 65 psi or so after I take away voltage to the pump.
what do you guys think?
But wouldn't that cause a lean condition

 

The PCM can accurately compensate for fuel pressures anywhere from 60psi to 66psi. It keeps the fuel mixture correct by varying the pulse width to the injector, (the amount of time that the injector is open). The higher the fuel pressure is, the less time the injector needs to be open.


Your max output pressure and leakdown is fine, (pump is fine). When the pump shuts off, leakdown does not drop below 72psi, which means any drop detected at the service port below 72psi, is in the plenum. Very doubtful that it's an injector or a spider line, or leakdown would drop to zero. More likely would be the valve plate in the regulator is not sealing completely until the spring pressure forces the plate shut. Although your leakdown to 50psi is "technically" out of spec, it's not what is causing your overly rich condition.


Sorry, haven't had time to really study the scan tool data yet, but at a glance, it's running quite rich. I'll try to get to it tonight.