2000 blazer possible fuel pressure issues
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2000 blazer possible fuel pressure issues
hi all,
i seem to be having some possible fuel pressure related issues on my 2000 blazer, i have done some testing already but cant quite figure out for certain what the problem might be (i have already read the sticky post by captain hook regarding fuel pressure testing)
the only symptoms i have right now are a slightly longer crank time in the morning (about 3 seconds instead of instantly firing up) and possibly a slight decrease in power (runs and drives fine at normal speeds but if you stomp the pedal it seems to be missing some power. no stuttering or misfiring, just doenst feel like its running at full power) also, no check engine light or fault codes.
this is what i have already tried:
dead head fuel pump pressure test shows 108 psi at the fuel filter (this should rule out a clogged filter? also it is a brand new one) and drops to 64 after 10 minutes (this should be well within spec i suppose)
pressure test at schrader valve(key on engine off): on the first key cycle, pressure goes to 60psi and then over approx. 30 seconds it bleeds of to about 40, second key cycle: pressure goes to 60 and then proceed to hold 54 psi for quite some time, no bleed down (i should mention that cycling the key about 3 times eliminates the 'extended' crank issue, it starts instantly this way)
pressure when running seems to be around 52-54 psi (my haynes manual states anything within a 3-10 psi pressure drop from key off pressure is normal, dont know how valid that is though as the sticky post i read states all tests are done with key on engine of pressures)
i have taken off the airbox to check for fuel leaks inside the intake as i had seen someone suggest if your regulator leaks, you would be able to see 'wet spots' but it seemed dry
checked the fuel trims with my scanner, it is not running rich or lean, both banks show values within +/- 3%
only thing that also seems a bit out of the ordinary is that it seems to be idling at around 800rpm, just a tiny bit higher than what i would assume is normal (i guess 600-650 rpm?)
once it has ran, even if only for 5 seconds (so i know its not an issue with a warm engine), if you start it again within an hour or so it fires right up again so to me this points in the direction of a pressure leak but this contradicts my findings in testing. i can also rule out any ignition related issues as the plugs, wires, cap, rotor, and coil are new and confirmed to be in working condition
also as some background information, car has only 150k kms (90k miles) i bought this car about 6 months ago and before that it had sat for a very long time, it only drove 5k kms (3k miles) in the span of 10 years. it was a 200km trip home(about 125 miles) with no engine related issues, the very next day the coil gave out (hence why i decided to change all ignition parts along the way) all was fine after this, then it has sat stationary for a long time (i have changed every single steering and suspension component, all rubbers were worn out due to age) during this time it hasnt run so maybe by now the gas is also a bit old
the only engine related part i have changed is the egr line as for some reason the previous owner had done some sketchy welding to it (maybe it was broken or they tried to weld it shut for some reason)
sorry for the long read, im just trying to give you as much information as i can.
i would be happy to hear from you guys, im just thinking out loud here, any input would be appreciated. also sorry in advance for any spelling mistakes as english is not my first language.
i seem to be having some possible fuel pressure related issues on my 2000 blazer, i have done some testing already but cant quite figure out for certain what the problem might be (i have already read the sticky post by captain hook regarding fuel pressure testing)
the only symptoms i have right now are a slightly longer crank time in the morning (about 3 seconds instead of instantly firing up) and possibly a slight decrease in power (runs and drives fine at normal speeds but if you stomp the pedal it seems to be missing some power. no stuttering or misfiring, just doenst feel like its running at full power) also, no check engine light or fault codes.
this is what i have already tried:
dead head fuel pump pressure test shows 108 psi at the fuel filter (this should rule out a clogged filter? also it is a brand new one) and drops to 64 after 10 minutes (this should be well within spec i suppose)
pressure test at schrader valve(key on engine off): on the first key cycle, pressure goes to 60psi and then over approx. 30 seconds it bleeds of to about 40, second key cycle: pressure goes to 60 and then proceed to hold 54 psi for quite some time, no bleed down (i should mention that cycling the key about 3 times eliminates the 'extended' crank issue, it starts instantly this way)
pressure when running seems to be around 52-54 psi (my haynes manual states anything within a 3-10 psi pressure drop from key off pressure is normal, dont know how valid that is though as the sticky post i read states all tests are done with key on engine of pressures)
i have taken off the airbox to check for fuel leaks inside the intake as i had seen someone suggest if your regulator leaks, you would be able to see 'wet spots' but it seemed dry
checked the fuel trims with my scanner, it is not running rich or lean, both banks show values within +/- 3%
only thing that also seems a bit out of the ordinary is that it seems to be idling at around 800rpm, just a tiny bit higher than what i would assume is normal (i guess 600-650 rpm?)
once it has ran, even if only for 5 seconds (so i know its not an issue with a warm engine), if you start it again within an hour or so it fires right up again so to me this points in the direction of a pressure leak but this contradicts my findings in testing. i can also rule out any ignition related issues as the plugs, wires, cap, rotor, and coil are new and confirmed to be in working condition
also as some background information, car has only 150k kms (90k miles) i bought this car about 6 months ago and before that it had sat for a very long time, it only drove 5k kms (3k miles) in the span of 10 years. it was a 200km trip home(about 125 miles) with no engine related issues, the very next day the coil gave out (hence why i decided to change all ignition parts along the way) all was fine after this, then it has sat stationary for a long time (i have changed every single steering and suspension component, all rubbers were worn out due to age) during this time it hasnt run so maybe by now the gas is also a bit old
the only engine related part i have changed is the egr line as for some reason the previous owner had done some sketchy welding to it (maybe it was broken or they tried to weld it shut for some reason)
sorry for the long read, im just trying to give you as much information as i can.
i would be happy to hear from you guys, im just thinking out loud here, any input would be appreciated. also sorry in advance for any spelling mistakes as english is not my first language.
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