Do Not Sell My Personal Information Jump to content

Recommended Posts

I have seen this issue on the post before, and there was not any kind of answer to the problem

When I am driving aroung the 40-48mph mark and let off of the gas the car de-excelerates abnormally and when you give it fuel it jerks alittle bit.

I adjusted the throttle position sensor and the problem went away. Then the car started to idle alittle bit high around 900-1000 and at idle it would then shift through all of the gears so i put the sensor back to where it was. Any suggestions would be greatly appreciated. Being laid off every other week has been tough, i had just spent around 600 for ox sensors, brakes and filters so money is really tight, if i can adjust the senAsor what is the best place to put it?

And i do understand how to check with a meter, but would i still see this issue not at speed.

I just went to Jacksonville and back my car is getting aroung 28mpg I have replaced and keep this baby very well maintained just ask the old lady

Link to post
Share on other sites

When my Tacoma was doing this, I thought the transmision was going out. Looking on the forums, it was the mass airflow sensor was dirty. It was right downstream of the air filter, in the hose. 2 screws, pull it out and clean it with contact cleaner-not carb cleaner. Ran great. I started doing it every year or so. I have an SC400, but haven't looked to see if it's similar. Cheap fix!

Link to post
Share on other sites

The TPS is a tricky thing to fool with. It adjust more than just the idle. I would recommend setting it to the correct factory ohms.

The jerking you felt might be the transmission mount going bad. Its very common. The other thing it could be is the driveshaft rubber piece that attaches to the rear end. These are also known to go bad, due to dry rotting or abnormal wear.

I would check the TPS to the corrct ohm, and then if the problem still lies there, then check the 2 above items. Hopefully this will solve your problem. Keep us posted on your findings!

Link to post
Share on other sites
The TPS is a tricky thing to fool with. It adjust more than just the idle. I would recommend setting it to the correct factory ohms.

The jerking you felt might be the transmission mount going bad. Its very common. The other thing it could be is the driveshaft rubber piece that attaches to the rear end. These are also known to go bad, due to dry rotting or abnormal wear.

I would check the TPS to the corrct ohm, and then if the problem still lies there, then check the 2 above items. Hopefully this will solve your problem. Keep us posted on your findings!

Would you go by the ohms factor or by the voltage from 1- a 4.5 reference? If by ohms what exactly should I be looking for? I had thought that it was the transmission area at first, but when I took the air flow sensor and throttle position sensor apart and put them back into place I did not have this happen, the idle was just a little funny. So I put the throttle position back to were the yellow marks were at factory settings.

I am just curious if I can adjust this since there is available adjustment to be made there, and maybe save the $150 or could it be the mass air flow for $400?

There is noone here in South Georgia that can pull any codes off of this car, not even Toyota and 4 other mechanics, when I replaced the o2 sensors I was guessing at best as to what needed to be replaced, and I reset the codes myself, the lexus dealership is 150miles away so any suggestions would be great.

Thanks

Kevin

Link to post
Share on other sites

I would start with the correct ohm. I have tried to post a link, but havent found one yet.. Will keep looking for you. I believe you have adjusted it too much or incorrectly. They are very sensitive, even a hair turn, left or right. The TPS even adjusts the shift times in the transmission. I would call the Stealership and ask them for the correct area of volts for the TPS. Then go from there.

It might be your MAF but I wouldnt think so since your problem didnt start until you messed with the TPS. This is just my opinion and I wish I could help you more. Will keep looking.

Link to post
Share on other sites
I would start with the correct ohm. I have tried to post a link, but havent found one yet.. Will keep looking for you. I believe you have adjusted it too much or incorrectly. They are very sensitive, even a hair turn, left or right. The TPS even adjusts the shift times in the transmission. I would call the Stealership and ask them for the correct area of volts for the TPS. Then go from there.

It might be your MAF but I wouldnt think so since your problem didnt start until you messed with the TPS. This is just my opinion and I wish I could help you more. Will keep looking.

I appreciate that, I had the issue before I started messing with the TPS. Is it possible to have a dead spot on the tps? I do agree that it will affect the transmission because when I thought that I had it fixed the tranny would shift through all of the gears in idle.

Seems that even if I buy a new one I will have to go through an adjustment period or will I have to take reading with a new one as well?

Thanks and I will start surfing the net as well.

Link to post
Share on other sites

This is what I have found so far on the net, I will adjust it some time this weekend and update all if this fixes my issue or I will just have to get off the cash for a new one. I assume that I will have to adjust the new one this way as well.

To me, it's not worth messing with the TPS. It seems to affect the tc lockup more than anything. Voltage too low and the lockup is erratic. Voltage to high and the tc won't unlock without hitting the brake. Either is really annoying. And note, I'm only talking hundreths a volt difference here. I find that about .55 volts (engine off, throttle closed) works best. .60 is too high and .50 is too low.

Link to post
Share on other sites

Okay, so I could not wait until this weekend. My voltage was set at .5967 volts. I set it to .5500 volts and manually ran the throttle up to wot. which read at 3.899 volts not the 4.5 that I was expecting. So I took the car down the road for a few miles. It seem to do very well, no drop off when coasting around 45, so either I moved the dead spot to another speed or the TPS is that sensitive to that few of volts. If I see that it does not work I will replace and keep you all updated.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...