1994 Q45 dies on inclines
1994 Q45 dies on inclines
I purchased a Q45 from my Aunt who I know did routine maintenance to her car so it was in really great shape. However, my car has been repeatedly stalling on inclines and generally at exits. They are not very steep and seem to be the same ones that I try to use in my daily commute. I have a new battery and alternator and had the fuel filter changed. A dealer suggested that the 94's had an issue with gummy valves. I hope not because they want $2000 to repair. It just seems like a fuel related matter to me. Can anyone help? I'm a girl, not a mechanic so please don't get too fancy on me with the terminology.:~)Thanks so much.
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Q45tech
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- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: 1994 Q45 dies on inclines (bugme)
Acceleration or going up an incline can require 10-30 times more fuel per second than just idling or cruising at a steady speed.With these symptoms the first thing we check is fuel pressure under real world conditions. SINCE as they age fuel pumps produce less and less fuel pressure. The engine is starved for fuel and cannot create enough power.The stalling may also mean that the electronic fuel pump speed controller has been damaged by the worn pump so that one of its 3 speeds has failed when you try to accelerate the ecu commands max fuel pump speed but the FPCU may just open the circuit and the engine dies.
Why we monitor fuel pressure on the road under all conditions of operation.
If the fuel pump has not been replaced in the previous 6 years it is most likely the cause.
Very common failure.
Dealers change fuel pump, fpcu, and fuel filter to avoid come backs due to missing something [rare that they will spend hours diagnosing since customer won't pay] and in the long run all the components fail anyway.
The point is a old worn fuel pump will destroy a FPCU unless changed EARLY and frequently.
The other proble is the pump is not designed to work with E10 gasoline which often has above spec water which cause rust and corrosion inside the pump FASTER than non E10 gasoline. Much depends on local weather days of rain , humidity, and laziness of the personel at tank farm, gas station etc................not daily testing for water in tanks.
Why we monitor fuel pressure on the road under all conditions of operation.
If the fuel pump has not been replaced in the previous 6 years it is most likely the cause.
Very common failure.
Dealers change fuel pump, fpcu, and fuel filter to avoid come backs due to missing something [rare that they will spend hours diagnosing since customer won't pay] and in the long run all the components fail anyway.
The point is a old worn fuel pump will destroy a FPCU unless changed EARLY and frequently.
The other proble is the pump is not designed to work with E10 gasoline which often has above spec water which cause rust and corrosion inside the pump FASTER than non E10 gasoline. Much depends on local weather days of rain , humidity, and laziness of the personel at tank farm, gas station etc................not daily testing for water in tanks.
Re: 1994 Q45 dies on inclines (Q45tech)
Thanks so much for the assessment...I really appreciate it. Apparently no way to check and see if the fuel pump is working in all three speeds I guess? I have a mechanic (non dealer) that's pretty easy to deal with so may do the diagnosis...though not sure if he would know how to assess the fuel pump scenario. Also...assume the E10 gas you mentioned is ethynol added? I've been suspicious that it's an issue even in the premium that I use...and especially for older cars.