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Matt, Mechanical Engineer
Category: Kia
Satisfied Customers: 22731
Experience:  BEng hons Mech engineering, in auto industry 22 years
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My 2.9 kia sedona deisel is running slow with no power

Customer Question

my 2.9 kia sedona deisel is running slow with no power
Submitted: 2 years ago.
Category: Kia
Expert:  Matt replied 2 years ago.
Hello 1st consider changing the fuel filter as if this partially blocked this will reduce pressure at the main piump If OK then also check the connections to the EGR valve, if either the vacuum pipe of electrical connection are damaged / corroded then the EGR can be on all time which certainly will hurt performance. Its also possible that its a fault with the EGR valve so its worth removing the valve and cleaning it out with brake cleaner, if it looks particularly clogged then replace it. If this is OK then check the small vacuum lines to the turbo and its connected control solenoid on the bulkhead, any cracks or leaks can give turbo issues and its best to have the boost pressure measured actually measured with a boost gauge to check that the turbo is healthy and that the sensor is reading correctly If its a variable vane turbo (they’ll be an actuator on the turbo body - but not a wastegate) then check its vacuum pipework as above and check the connections to the diaphragm / solenoid valve Also worth checking that the glow-plug relay is switching off as they can stick on and leave the glow plugs also on - on some cars this can force it into limp home Also worth considering adding a bottle of injector cleaner into the tank as a clogged injector nozzle will reduce power and give poor combustion - the next stage on from this is to remove all the injectors and have them ultrasonically cleaned and flow checked Also check all the high pressure hoses post turbo/s for any split hoses or cracked metal pipes, also check the ends of the intercooler as its not unheard of to pop the end caps off under high boost.
Customer: replied 2 years ago.
changed fuel filter cleaned egr valve went in to change air filter and it was ripped and blocking the air flow thought it was sorted test drive it would hardly go untill it seems if is getting more air also changed the air flow switch any thoughts as to why its still going slow.
Expert:  Matt replied 2 years ago.
hellohave you checked all the other things I've suggested?
Customer: replied 2 years ago.
took off air box went like a dream put air box back on and air flow switch would not pull you out of bed disconnected air flow switch and goes fine can it be run like this or will it cause damage as i have already changed the air flow switch.
Expert:  Matt replied 2 years ago.
Hello when you remove the airbox are you also removing the air flow sensor? if so then this forces the engine ECU to use other engine sensor to run in a backup mode and confirms the issue is with that sensor or the wiring to that sensor if the sensor is still in place then look inside the airbox for any restrictions , bent parts, blocked filter or other debris in front of the sensor
Expert:  Matt replied 2 years ago.
do you still need help?
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