Fuel hold pressure checks ok = not leaking injectors?
08-01-06, 09:21 AM
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Fuel hold pressure checks ok = not leaking injectors?
quick, and self explanatory question:
is it sound logic to assume that if my hold pressure is at 30 psi after 5 minutes (the manual states 18psi or above is good), then my injectors are not leaking?
is it sound logic to assume that if my hold pressure is at 30 psi after 5 minutes (the manual states 18psi or above is good), then my injectors are not leaking?
08-01-06, 01:54 PM
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thanks for the reply. the problem is hard starting, just like everyone else on the board, so it seems.
i've done a little bit of checking here and there. the water thermosensor seems fine, i put it in a cup of room temp water, checked resistance, ice water, checked again, and finally boiling water. the resistances seemed to be in line with what the manual says. i checked the fuel pressure, as i already stated. all the plugs seem to be plugged in, and there appears to be no vacuum leaks.
the problem arose suddenly, as in i hadn't done any work on the car for some time prior to the hard starting started. so i'm inclined to think its not something like a vacuum leak or unplugged sensor. i couldn't start the car for the longest time, until i poured some atf in the chambers, and de-flooded it by cranking and cranking with the plugs out, and the EGI fuse out. then i put in brand new plugs, and it fired right away. it smoked like crazy for a good 10 minutes. i smelled the smoke, it smelled like a campfire. i looked under the car, and the cat was glowing red hot, and pieces of red hot catalyst would come out the exhaust if i revved it. i'm thinking it got drenched in fuel. so i shut it down.
it will start, but the only way i can get it to fire is by opening the throttle a little bit while cranking. all the way to the floor (cutting the fuel) does not help. barely open seems to be the best.
just before the hard starting happened, i noticed the coolant level in the overflow came up quite a bit. i immediately thought it was a blown coolant seal. upon further inspection, i noticed my radiator cap's rubber ring was deformed, so i bought a new one, and so far the coolant level has remained constant.
i have yet to check compression.
other symptoms, may or may not be related:
- occasionally, the throttle will stop opening prematurely. it feels like there is something in the way. if i press hard on the pedal, it will free itself and the full range of throttle travel will be back.
- the car will idle high, like 2000 rpms, even though the temp gauge is clearly in the middle between hot and cold. it will do this for 10 minutes or so, until finally it settles to the normal 750. if i play with the throttle a bit during this, i can manually get the revs to drop by pressing the throttle plates closed. it will oscillate revs up and down, as if there were a vacuum leak.
- i tested the fuel pump resistor relay. i think it is bad, there is no resistance between 3 pairs of terminals. according to HAILERS, this should not effect the fuel delivery during cranking, since the pump should get 12volts during cranking, which is what the car will default to anyway in the event of a bad relay.
-once the car is warmed up fully, it drives 100% normally. no smoke, same power as before.
any help is appreciated. the compression test is coming sometime this week when i have time to work on it. sorry for the long post
i've done a little bit of checking here and there. the water thermosensor seems fine, i put it in a cup of room temp water, checked resistance, ice water, checked again, and finally boiling water. the resistances seemed to be in line with what the manual says. i checked the fuel pressure, as i already stated. all the plugs seem to be plugged in, and there appears to be no vacuum leaks.
the problem arose suddenly, as in i hadn't done any work on the car for some time prior to the hard starting started. so i'm inclined to think its not something like a vacuum leak or unplugged sensor. i couldn't start the car for the longest time, until i poured some atf in the chambers, and de-flooded it by cranking and cranking with the plugs out, and the EGI fuse out. then i put in brand new plugs, and it fired right away. it smoked like crazy for a good 10 minutes. i smelled the smoke, it smelled like a campfire. i looked under the car, and the cat was glowing red hot, and pieces of red hot catalyst would come out the exhaust if i revved it. i'm thinking it got drenched in fuel. so i shut it down.
it will start, but the only way i can get it to fire is by opening the throttle a little bit while cranking. all the way to the floor (cutting the fuel) does not help. barely open seems to be the best.
just before the hard starting happened, i noticed the coolant level in the overflow came up quite a bit. i immediately thought it was a blown coolant seal. upon further inspection, i noticed my radiator cap's rubber ring was deformed, so i bought a new one, and so far the coolant level has remained constant.
i have yet to check compression.
other symptoms, may or may not be related:
- occasionally, the throttle will stop opening prematurely. it feels like there is something in the way. if i press hard on the pedal, it will free itself and the full range of throttle travel will be back.
- the car will idle high, like 2000 rpms, even though the temp gauge is clearly in the middle between hot and cold. it will do this for 10 minutes or so, until finally it settles to the normal 750. if i play with the throttle a bit during this, i can manually get the revs to drop by pressing the throttle plates closed. it will oscillate revs up and down, as if there were a vacuum leak.
- i tested the fuel pump resistor relay. i think it is bad, there is no resistance between 3 pairs of terminals. according to HAILERS, this should not effect the fuel delivery during cranking, since the pump should get 12volts during cranking, which is what the car will default to anyway in the event of a bad relay.
-once the car is warmed up fully, it drives 100% normally. no smoke, same power as before.
any help is appreciated. the compression test is coming sometime this week when i have time to work on it. sorry for the long post
08-01-06, 02:07 PM
#4
Originally Posted by carsaregood
i have yet to check compression.
occasionally, the throttle will stop opening prematurely. it feels like there is something in the way. if i press hard on the pedal, it will free itself and the full range of throttle travel will be back.
the car will idle high, like 2000 rpms, even though the temp gauge is clearly in the middle between hot and cold. it will do this for 10 minutes or so, until finally it settles to the normal 750.
edit: Also, even though the injectors aren't sitcking open, it doesn't mean they aren't related to the hard starting. They might close fine, but when it comes to opening to the correct degree to inject just enough fuel for start up, they either go too far or too short.....you may want to have them flowed and cleaned once you check your compression
Last edited by classicauto; 08-01-06 at 02:11 PM.
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