OK, my 99 sat after a wreck for 2 yrs. I recently fixed it. NOTE** PLEASE RESPOND WITH RELATED INFORMATION. I AM SIMPLY NEW TO TOYOTA. IVE BUILT HONDA/ACURA AND MITS FOR 15 YRS.
*EMPTIED TANK AND CLEANED INCLUDING PUMP (TESTED)
*FLUSHED FUEL LINES
*CLEANED AND REPLACED F I WITH NEW SEAL KIT
*PLUGS ANS WIRES
*AIR FILTER
*OIL AND FILTER
*COOLANT
*CHECKED OTHER FLUIDS
So my qusetion is: What else would cause a sputtering problem during acceleration?? Its not a "rich" issue (no smoke, smell or buildup on plugs). Plugs were dry and tannish (usually from running lean). Fuel pressure up front during idle. Can the fuel pump weaken from sitting or intermittently? It will start, idle smooth, CRAPPY ACCELERATION, then cruise fine........
Thanks for ANY help!!!
Kobe
Oh yeah, can it have enough pressure @ idle and not at throttle?? and does the pump control pump pressure or the F P Regulator??
Last edited by HalfBreed56; 03-12-2010 at 08:32 AM.
Did you clean the fuel rail itself? Sometimes it can get pretty gummed up, especially if gasoline sat in the rail for that long, those solvent kits don't always get all the gum out. Did you replace the fuel filter and the fuel pickup sock, when you have the fuel pump out of the tank? Did you verify ignition timing is good?
This generation of Corolla started using the returnless fuel systems. Fuel pressure and supply demands are handled by the PCM. Sounds like there could be an obstruction in the fuel system (when demand for fuel is high, car runs poorly). Could be a bad pump, gum or varnish clogging something else down the system.
If you have access to a OBD-II datalogger - see what the fuel trims are like during accelerations runs. Could be something unrelated to fuel delivery - could be an exhaust leak or bad O2 sensor.
Did you clean the fuel rail itself? Sometimes it can get pretty gummed up, especially if gasoline sat in the rail for that long, those solvent kits don't always get all the gum out. Did you replace the fuel filter and the fuel pickup sock, when you have the fuel pump out of the tank? Did you verify ignition timing is good?
This generation of Corolla started using the returnless fuel systems. Fuel pressure and supply demands are handled by the PCM. Sounds like there could be an obstruction in the fuel system (when demand for fuel is high, car runs poorly). Could be a bad pump, gum or varnish clogging something else down the system.
If you have access to a OBD-II datalogger - see what the fuel trims are like during accelerations runs. Could be something unrelated to fuel delivery - could be an exhaust leak or bad O2 sensor.
*Cleaned the entire system. did NOT change the basket (after reading this, i checked and there is a little black inside, buy seems to let fuel in and out ok)
*Timing fine
*exhaust leak or o2 sensor, i dont know. the car ran fine, then started running like crap. then i cleaned everything, it ran fine for 25 miles, and did the same thing.
*Fuel pump- this was my next idea. could it sometimes just fail to push proper pressure or is that controlled by the FPR?
Also, i never actually removerd the fuel rail, but it was flushed with gas and seafoam for a while. injectors were pulled and cleaned too.
Still doing the same. hesitation and chugging up to speed, then cruise fine. It takes a while to get cruise speed though.
One things for sure, its not a rich problem, i smell NO extra unburnt fuel. Definatly a fuel delivery prob.....
Double check that you got a good electrical connection on the fuel pump. Try checking the resistance on the pump itself - should be 0.2-3 ohms. Anything more could mean a dying fuel pump. FPR is set for 44-50PSI at no vacuum - ECM commands the pump on/off to keep up fuel pressure.
Possible that there is a fuel leak somewhere - maybe a soft line got rotted out over time. Air being pulled into the fuel line would cause stumbling/hesitation at higher loads demanding more fuel volume. Could be at idle/cruise - the extra manifold vacuum is pulling the necessary amount of fuel, masking the issue of a failing fuel pump.
That is possible - if something has jammed up the spring or diaphram inside the FPR - that could cause the pressure issue you are experiencing. Not sure if you can clean those out effectively, that diaphram could be punctured, distorted or cracked - that case, just needs to be replaced. From what I've gathered, they are not-inexpensive - running around a $100 or so.
To be sure, you need to install a SST on the fuel hardline under the hood. That way, you can T-into the fuel line and take a pressure reading directly. The returnless fuel systems generally do not have a ready valve like this did on the conventional return style fuel systems. Not a whole lot you can do about it - as nearly all current vehicles use returnless systems.
I forgot to ask - how does it run when you gun the throttle while in park? Does it still stumble at high engine revs or only does this when you have under a load?
I forgot to ask - how does it run when you gun the throttle while in park? Does it still stumble at high engine revs or only does this when you have under a load?
most of the time, it fires up and idles fine, revs with VERY little hesitation and then after 1 or 2, its fine with no load. Smokes a little, but no smell.
as soon as it goes into gear, it starts. if i barely throttle, i can get 50mph pretty quick. if i step down, it feels as though diff cyl are misfiring (ruling out a cyl leakage to a certain one) it sometimes will almost totally clear up, then fall back into the same pattern again. This takes 5 min intervals to reach peak (but still extremly poor, chugging performance). once, i took out fuel pump, injectors and cleaned everything, it fired up fine, ran 20 miles, started again and drove home fine. then an hour later, same symptoms. after trying first remedy again and again (and replacing seals again from constant cleaning and removing), still no luck.....
Just curious - in what way was the car "wrecked"? Just a little body damage, or was it more substantial. Front, rear, side?
Bitter makes a good point, possible that the catalytic converter got slagged over time - could be a physical obstruction inside the exhaust piping.
Example - for some strage reason, my older muscle cars had quite a field mice and chipmunks always nesting inside the exhaust pipe. Fired the cars up every once and while and on occasion, blown a chipmunk or mouse straight out of the exhaust.
Just curious - in what way was the car "wrecked"? Just a little body damage, or was it more substantial. Front, rear, side?
Bitter makes a good point, possible that the catalytic converter got slagged over time - could be a physical obstruction inside the exhaust piping.
Example - for some strage reason, my older muscle cars had quite a field mice and chipmunks always nesting inside the exhaust pipe. Fired the cars up every once and while and on occasion, blown a chipmunk or mouse straight out of the exhaust.
Thats funny!!! OK prob solved. Thanks for everyones help. Here is the summary:
Car was in a front end collision back in May 2008 and sat until 3 weeks ago. After doing some body cut/weld and replacing the radiator support, all front end exterior panels and the radiator/AC and the intake manifold (cracked it).
I fire the car up and noticed it was a little slower than before(figured it was just from sitting, since I seafoamed the tank. After 20 miles, it began sputtering. 90% OF WHAT YALL POSTED NEEDED ATTENTION!! THANKS!
*Cleaned fuel rail
*Cleaned MAP and MAV and all other accessable sensors
*checked cat
*found small air leak in intake manifold
*found 2 small leaks in the FI area (needed better grease for installation)
*bad belt tentioner
*emptied and cleaned fuel tank and pump
after that it ran pretty good. reset the C E light and it runs like new....
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