98 LS400 limp home mode
#1
98 LS400 limp home mode
History:
I've been having issues starting my car for a while now. The car had its starter changed and has a brand new battery, so it's not either of these things. I'll have to hold the key in the start position for a good 3-4 seconds before letting go. Otherwise, the car won't usually start.
I've also been noticing that the car hits its "rev limiter" at like 3 or 4k RPM sometimes. I'll try to accelerate, and if the tach hits like 3k, it just bounces off 3k as if that were the redline.
Also, the A/C hasn't been blowing as cold as I've been used to.
These things led me to suspecting the fuel pump. But I didn't do anything because most of the time, the car drove normally.
Today:
When I was driving, the car went into a limp home mode. The speed was rapidly dropping even though I was basically flooring the pedal. I pulled over and tried to restart the car. The engine turned over, but no longer how long I held the key in the start position, the engine wouldn't stay on after I let go of the key.
I came back to the car about an hour later after going back home. I tightened the positive battery terminal, as that was loose. I also added 2 gallons of fuel and it started up without much issue. I then attempted to drive around some more, and within a few miles, it went into limp home mode again and I had to pull over. I tried starting the car again, and it didn't want to. It did actually start one time, but the revs were fluctuating rapidly between about 700 and 1000 and I just shut the car off after that.
So...I'm waiting on the tow truck. I'm about to replace the fuel pump. Should I just go ahead and do the fuel pump? What other issues could it be? Could it be the ECU, or was that issue fixed by '98? Is testing the fuel pump easy?
I've been having issues starting my car for a while now. The car had its starter changed and has a brand new battery, so it's not either of these things. I'll have to hold the key in the start position for a good 3-4 seconds before letting go. Otherwise, the car won't usually start.
I've also been noticing that the car hits its "rev limiter" at like 3 or 4k RPM sometimes. I'll try to accelerate, and if the tach hits like 3k, it just bounces off 3k as if that were the redline.
Also, the A/C hasn't been blowing as cold as I've been used to.
These things led me to suspecting the fuel pump. But I didn't do anything because most of the time, the car drove normally.
Today:
When I was driving, the car went into a limp home mode. The speed was rapidly dropping even though I was basically flooring the pedal. I pulled over and tried to restart the car. The engine turned over, but no longer how long I held the key in the start position, the engine wouldn't stay on after I let go of the key.
I came back to the car about an hour later after going back home. I tightened the positive battery terminal, as that was loose. I also added 2 gallons of fuel and it started up without much issue. I then attempted to drive around some more, and within a few miles, it went into limp home mode again and I had to pull over. I tried starting the car again, and it didn't want to. It did actually start one time, but the revs were fluctuating rapidly between about 700 and 1000 and I just shut the car off after that.
So...I'm waiting on the tow truck. I'm about to replace the fuel pump. Should I just go ahead and do the fuel pump? What other issues could it be? Could it be the ECU, or was that issue fixed by '98? Is testing the fuel pump easy?
#3
Last time I checked (a month ago), the codes had to do with the o2 sensors. I looked under the car and found one o2 sensor dangling from the underbody of the car (??!?!?!?!). I've neglected to fix the o2 sensors.
I wish I had a code scanner but I don't, so I don't know what codes there are right now.
The car is on its way home now, so when it's on my driveway I'll pull the ECU and check it out.
#4
I actually had that issue a few months ago. Misfires and codes about a bad vvti solenoid. I got brand new spark plugs, which didn't fix the issue. Then I changed both vvti valves and it was perfect.
Last time I checked (a month ago), the codes had to do with the o2 sensors. I looked under the car and found one o2 sensor dangling from the underbody of the car (??!?!?!?!). I've neglected to fix the o2 sensors.
I wish I had a code scanner but I don't, so I don't know what codes there are right now.
The car is on its way home now, so when it's on my driveway I'll pull the ECU and check it out.
Last time I checked (a month ago), the codes had to do with the o2 sensors. I looked under the car and found one o2 sensor dangling from the underbody of the car (??!?!?!?!). I've neglected to fix the o2 sensors.
I wish I had a code scanner but I don't, so I don't know what codes there are right now.
The car is on its way home now, so when it's on my driveway I'll pull the ECU and check it out.
#6
I pulled the main ECU and the ABS/Trac ECU as well. I looked inside the main ECU for bad caps. None found. At least none that were obviously bad.
I put the ECUs back and now the car won't even crank.
What happened?
I put the ECUs back and now the car won't even crank.
What happened?
#7
it sounds like what happened to my car when my mechanic improperly set the timing belt on the camshafts. He was a couple teeth off and the car backfired and RPMs wouldn't go over 2-3k without severly bogging and cutting power.
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