I have a 99 Silverado with a 5.3 thats 4x4 and my wrench friend and I
checked the fuel pressure the other day and it's reading between 52 to
when you first turn the ignition on it jumps up to 58 then falls to a steady
52 psi. with the motor running i get the same 52 psi and if you open the
throttle it jumps to 58 again.
now after doing some reading around I found out that the pressure is sposed
to be this 379-427 kPa (55-62psi).
The reason I checked the fuel pressure is because the truck hesitates pretty
bad sometimes when you gas it.. just acts like it's not getting the fuel it
needs. we thought it might be the regulator, could i have a problem there?
the fuel pump is new (10k miles ago) and so is the filter (about 2k miles
ago) also got a new air filter and the MAF has been cleaned.
I know there are alot of other things that could cause this (injectors,
plugs, wires etc.) but I'm trying to narrow them down..
I'm also thinking I have problem with the torque converter because I'm still
experiancing the jerky down shirts and take offs..
one other thing is the throttle sticks pretty bad sometimes. you have to
push it kinda hard to "break it loose" which causes the truck to want to
really take off.. except it can't because it's hesitates.
Any input would be greatly appreciated.
Your throttle sticking is caused by carbon build up at the air horn. Pull
the big hose of the front of the intake and there is a throttle plate. Use
some carb cleaner and get all that carbon off. Another thing that works is
to jack up the idle by about a 100 rpm. The adjustment is an allen screw.
Its a real little thing that points upward. Its under the part where the
throttle cable is attached.
Thanks, I'll check both of those out.
I guess the other reason I'm asking this question about the fuel pressure is
to see if i need to have the pump replaced since it's still under stop
warranty. (for low pressure)
The throttlebody for that year had problems. I think GM had a secret
warranty on the problem. You might want to call a dealer and find out. If I
remember the throttle shaft hole would elongate causing it to stick. Do a
You sure it would apply to the Suburban of that year? You have the
5.7L engine, I thought the TSB covered the 5.3L engines. Also, a TSB
is just a way of relaying updated service info to the dealers, or to
alert dealers to some problems they've seen, it is NOT a gauranteed
free fix for the customer...
My 99 has had problems with the fuel pump scaling up this is in part due to
design. If the tank is running at the last quarter tank or less the pumps
run hot. This causes pump failure and at a point less than 50 psi. the
injectors won't open this can cause a no start or the truck to stall. The
worst part of this is that the pump and sender assy. was not cheap! The
recommendation is never let it go past 1/2 tank. when gas is at 94.9 cents
per litre this seems impossible!
I try very hard not to let mine get below 1/4 tank.. i think i might have
got a bad pump.. the warmer it is outside the worse my problems seem as far
as the motor hesitating and acting like it's not getting fuel.
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