Just idles-won't take acceleration.

[Grubby Paws]

Have a 92 Loyale with around a 1988 1800 throttle body injection engine. The engine will start and idle, but I can't give it gas. Just the slightest hair-touch of the accelerator and it dies. It started this last spring. I would let it warm up for a few minutes and then it would be fine. It sat for the summer and now I went to get it ready for another Maine winter. It played the same game with me again, but this time decided to die while on the road and going up a hill. It has now permanently gone to only starting and idling, with much effort, but will not take the gas. It doesn't matter if it's cold---or I let it idle and warm up. I took a guess at the "throttle body sensor" and replaced the whole carb and sensor as one unit. Still--it has the identical situation. Had an extra computer--so swapped that too. Still the same. Any thoughts would be greatly appreciated. Thanks;-)))

[Mark Humble]

Coolant Temp Sensor or fuel pressure.

[85Sub4WD]

I'd replace the fuel filter for starters (driver's side, near brake master cylinder), just make sure you de-pressurize the fuel system first, otherwise you will get a nasty surprise when you take the fuel line loose

 

I would check the plugs, spark plug wires, cap, and rotor too, just for good measure

[subiemech85]

throttle position sensor may need to be re-set

check for codes

blocked air intake

[Subaru Jim Maple Ridge]

There is a possibility of a large vacuum leak, i.e. EGR valve or defective air control. At idle, vacuum is fairly high, but as soon as you touch the pedal, she will just quit. My guess, since you mentioned no CEL or codes.

[Grubby Paws]

Good idea on the temp sensor. That might explain why it now stopped while driving---if the sensor went bad and now thinks the engine is still cold. Hence it being back to the cold idle-only situation. But I still wonder where that would be coming from. Also I thought fuel pumps usually ran or quit on Subies. can they have low pressure and idle only> If so---I can check for pressure tomorrow. what range should I be in? Around 35 or 40 pounds?

Coolant Temp Sensor or fuel pressure.

[Grubby Paws]

There are some great ideas showing up here. But because I replaced the whole carburetor, with the sensor already installed (from junk yard) and the situation is identical, I tend to be eliminating any wrong sensor setting. I haven't been able to pull any codes out of it though. Or at least last spring I couldn't. I can only get a repetitious flash of 7, which I believe simply meant it was a California emission spec vehicle. And yup---I've checked for air blockage. I haven't replaced the air sensor yet. But again---this is sooooo strange with the throttle. You barely have to touch it. It's hard to believe that I'm even moving the throttle plate enough to matter. Yet I'm assuming the minute the throttle sensor detects this tiny movement---something is electronically signaled and fails.

throttle position sensor may need to be re-set

check for codes

blocked air intake

[Grubby Paws]

Hmmmmm---I suppose it almost acts like a huge "lean-air" mixture. But it is soooo defined by such a tiny fraction of a touch to the accelerator. As I mentioned in another reply here---it acts so much like it is an electrical sensing of the throttle being moved. But let's say it is that. Is there something else that could electrically trigger a massive air leak---once the throttle was recognized as moving? I believe there is an electronically activated solenoid that allows air to flow and move the EGR. But that wouldn't trigger to full bore would it? I suppose I should look that area over though. Again--thanks for the thoughts. I guess I still have a lot of stones to turn over before I give up on it.

There is a possibility of a large vacuum leak, i.e. EGR valve or defective air control. At idle, vacuum is fairly high, but as soon as you touch the pedal, she will just quit. My guess, since you mentioned no CEL or codes.

[Mark Humble]

If you have any spray carb cleaner or starting fluid on hand, you might try squirting some in the throttle body just as you start to open the throttle to see if it is in fact running lean. If it still dies, then I would start looking at the ignition system.