So my engine cuts out when I really hammer on the gas sometimes. It doesn't stall or anything just cuts out for a second and then resumes fine but by that time I've let off the gas considerably. Has anyone had a similar experience that they have dealt with successfully? Could it be something as simple as I need to run a higher octane gas? Or possibly I need to shut off the vehicle skid control so the car doesn't think it's going to break loose.? Thanks in advance

 

Hey, welcome to Club Lexus

Can you explain a little more in detail what you mean by cut off? It could be a few things, possibly a clogged fuel filter in which when you step on it, the pump cant throw enough fuel fast enough, I'd start there. Also, whens the last time you did a tune up? Could be a a spark issue. Lastly, if you can re create the 'cut off', then yes, disable the skid control and see if that solves it.

Another thing it could be is in the tranny and it not shifting quick enough. I've heard of this and too am experiencing it. Honestly, I'm pretty damn good with everything in automotive, but transmissions I'm still below a novice. You can try our search feature and focus on transmission threads because I've seen quite a few threads on this.


Again, welcome!

 

Well I don't really know how to explain it any better . It doesn't stall ..it's just a momentary power loss, by the time I let off the gas and hit it again the acceleration is back. I don't think it's a transmission problem but it's possible. I drive it in manual mode and use the paddle shifters , it's never happened in 3rd gear only in 4th . I'm getting the timing belt done Tuesday so I don't really want to push it again yet until I get that done because there's no history of it being done that I can find and it's got 280k on it . Im going to see if I can find the fuel filter so I can check it out ...I'm still fairly new to the lexus cars . I think your probably right about it being a spark issue or fuel delivery ...the cars had a tune up in the last year supposedly . I know when the vehicle skid control is off it responds faster so I'll test that too once I get the timing belt done Tuesday . In the meantime I'll check the tranny threads and possibly the fuel filter . Thanks for the advice , I'll let ya know what I find.

 

When you get that 'cutoff' feeling, is it like a bog where you hear thrrrrrr sound (roll the "r" like Spanish to get the sound I'm talking about ) or is it more of a hesitant? If its the thrrrr sound, yea its definitely a fuel/air issue. I'd check your MAF sensor if I were you too. With all those miles, could be a dirty MAF and definitely a possible clogged fuel filter. For some reason I hear a lot more from the v8 guys having significant performance changes by swapping out the filter.

 

So I replaced the timing belt because it still had the original after 270k km. Worst I'd ever seen without breaking . Replaced the fuel pump as well as the filters . Car did same thing today on slight hill... only ever happened in 4th gear. Similar to a tranny slip but it's just not it. Going to try cleaning MAF sensor like you suggested. It must be either not getting enough air/fuel mix when I floor it due to dirty maf and or it needs new plugs because it can't burn the fuel fast enough . It just gaps right out for a second or two then its fine . I'll post again if i can narrow down the problem and get it to simmer the f$#k down. Still no error codes or cell light have occurred.

 

For the heck of it, check your tranny fluid. Color (should be in the red color, not in the brown color), smell (smell for burn flavor) and feel it between your fingers for metal particles.

 

I did 5 drain and refills a couple months ago leaving only about 28% of the old fluid . there were some super fine metal particles in the pan but not alot and no large shavings .Colors looking healthy now.

 

are you still having problems with your hesitation issue at 4,500?

 

Not sure if this helps but the only hesitation problems I've ever had with my '99 GS400 was a cracked hose near the purge valve. It always felt like a slight power loss but took a while to figure it out.

 

Yeah I am . I mean its only happened 3 times since I've had the car for 8 months . It's just odd.. and I'd like to fix the problem but it's a 98 so I'm not going to just start throwing money into it doing guess work . 2 of the 3 times it's happened I was on an incline . I'm going to try cleaning the MAF sensor but it's only happened in 4th gear when I floor it..one would think it would happen in other gears as well if that was the problem . And I don't even think it hits the high rpm before it does it..happens pretty fast.

 

Here is the area I was talking about...you may have to take off the engine cover to see it better. It's on the drivers side. Check the hoses for cracks or separation.

 

Thanks for the tip , I'll check it out. Mines more like a total power loss though . Doesn't feel like the tranny ... it's more like it goes to take a big gulp of air or gas and cant enough so it just cuts out .

 

Dam I wonder if it's the vehicle skid control kicking in so it doesn't bust loose on me.

 

I know this thread is about 9 years old, but have you figured out what the issue was? I'm having the EXACT same issue

 

Had to run higher octane fuel.. the cheap **** caused the engine management system to retard the timing.