1FZE 97 LC power loss _ Please Help (1 Viewer)

Joined
Apr 9, 2013
Messages
69
Hi Everyone!
I am in dire need of help. My 1FZE 97 LC has started losing power.
This problem is not consistent as to when it happens. Sometimes after 5 minutes when I first start up in the morning.
Sometimes it will run great first 15 - 20 minutes around 3 miles then starts acting up.

Here's what's going on: If its running ok for the first 3 or so miles, upon a stop sign or slowing down for a light, It will drop idle suddenly to about 400 RPM and shutter and stumble and struggle to keep idle. I give gas and it revs. when I release gas it goes right back down. I usually have to shift to N and put foot on brake while other on gas just to keep it from cutting out. It also refuses to give me anything when accelerating . That's intermittent as well. When she's running good its all working as should. Once it starts this drop in RPM it won't cooperate. Sometimes not wanting to get over 2000 RPMS.. I have to feather and gently go with gas to get it to straighten up.
We just got a bad storm and on way home, Roads were packed with snow. I had no trouble with slipping on road. the trouble i has was inclines. She just didn't want to give me any power to go up the hills she does all the time. Now on a normal day since this started (no snow) she seems to be hesitant to go up those same inclines.
I'm wondering what is causing this loss of power.
I have NO Cats. they have been removed.
I do have an EGR code.
Had an ETC sensor code.. Replaced the sensor
Took to someone to read codes: beside the EGR and the O2 sensor codes i knew about it had misfire on all cylinders . I'm assuming because of this loss of power issue.
We checked the distributor cap.. clean as whistle. Its a fairly new distributor cap ( less than a year ) new spark plugs and wires.
My mechanic is Specialized in these vehicles and owns one. Its just that hes so booked and with another round of snow fall upon us I cant get it to him. I have to drive it because its all i have. I'm just needing some info on possible issues that could be problem to keep it going until i can get it taken care of.
Haven't checked the EGR wiring that I've read to check.
It also is running very rich in fuel. So was thinking it was an air/ gas ratio issue.
Also, Possible vacuum line. I'm also hearing. The problem is. I understand these possible causes but dont actually know what is what to check.
Any advice is greatly Appreciated! Help a Sista out,, :)
Cindy
 
Joined
Dec 10, 2007
Messages
7,621
All the above:

Check out this thread, scroll down to Post #39:


Also look at the two smaller diameter vacuum hoses on top of the valve cover close to the larger rubber air intake hose mentioned above (see photos in thread, click to magnify):

Ripped air intake duct with breather and PCV hoses marked.jpg
 
Last edited:
Joined
Apr 9, 2013
Messages
69
Hi Everyone.
An update... Pulled the TPS to see how it would run while connected to the OBD2 scanner. Ran about 5 miles to the store and back with the sensor out. I ran so good and consistent. The scanner was saying that it was running slightly lean. Could be to the O2 sensor code.
Anyway. PLUGGED THE SAME TPS back in and ran around for about 1.5 hrs today. Making sure I had a couple times where I completely shut off the truck to restart. She ran great the whole time! No stumbles. No power loss. Nothing to indicate that the same issue still existed. So... #fingerscrossed I'm hoping that it was a corrosion/ connection issue with the TPS. If it starts fumbling again, I will buy a new TPS and then go from there.
Thank you so much for all the help!
I will update if anything changes in this issue.

Next on list.... Front wheel bearings. $$$$
Cindy
 

flintknapper

SILVER Star
Joined
May 22, 2004
Messages
9,494
Location
Deep East Texas
Hi Everyone.
An update... Pulled the TPS to see how it would run while connected to the OBD2 scanner. Ran about 5 miles to the store and back with the sensor out. I ran so good and consistent. The scanner was saying that it was running slightly lean. Could be to the O2 sensor code.
Anyway. PLUGGED THE SAME TPS back in and ran around for about 1.5 hrs today. Making sure I had a couple times where I completely shut off the truck to restart. She ran great the whole time! No stumbles. No power loss. Nothing to indicate that the same issue still existed. So... #fingerscrossed I'm hoping that it was a corrosion/ connection issue with the TPS. If it starts fumbling again, I will buy a new TPS and then go from there.
Thank you so much for all the help!
I will update if anything changes in this issue.

Next on list.... Front wheel bearings. $$$$
Cindy

Excellent.......!
 
Joined
Apr 9, 2013
Messages
69
UPDATE 2:
After about 2 weeks of driving after reseating Throttle Positioning Sensor the truck started acting up again. So I bought a new one. Put it in and it was worse at first, After a couple more drives it started acting ok again but I still didn't have the power back to right. So, I replaced the upstream O2 sensor since it was coding. I've been driving for 2 weeks now and it's running awesome. When hooked up to OBDII the downstream O2 sensor is holding at 96%. I'm going to put in that new sensor to just to have better readings. As of now, I cleared all codes and for a week now, NO codes have come up. not even the original EGR that it's had for the last year. So, she's running clean right now and code free! I'm so stinking Excited!
 

flintknapper

SILVER Star
Joined
May 22, 2004
Messages
9,494
Location
Deep East Texas
UPDATE 2:
After about 2 weeks of driving after reseating Throttle Positioning Sensor the truck started acting up again. So I bought a new one. Put it in and it was worse at first, After a couple more drives it started acting ok again but I still didn't have the power back to right. So, I replaced the upstream O2 sensor since it was coding. I've been driving for 2 weeks now and it's running awesome. When hooked up to OBDII the downstream O2 sensor is holding at 96%. I'm going to put in that new sensor to just to have better readings. As of now, I cleared all codes and for a week now, NO codes have come up. not even the original EGR that it's had for the last year. So, she's running clean right now and code free! I'm so stinking Excited!


Good work. Sometimes finding ALL of the issues can take awhile. You were vigilant and it payed off for you.
 
Joined
Apr 9, 2013
Messages
69
Hi!
So now that I have new TPS, New O2 sensors,.... My LC is having a hard time shifting, It's throwing a PO501 code . Has anyone else thrown this code?
And is there only one VSS sensor near the transmission or is there one in the dash as well ? My speedometer is rock solid... meaning still working accurately according to the OBDII measures when driving. Thanks Everyone!
 

Users who are viewing this thread

Top Bottom