JohnAndic

Hey everyone. back again with my 98. Shes not throwing any codes, has a rusty Y-pipe which was patched but doesn't seem to be holding up well. My issue right now is with the RPM. More specifically the RPM on the highway when really giving the car gas my 98 will not REV past 4000. When I'm already traveling on the highway and give the car gas its a slow climb to 4000RPM but no higher. So as a result I have very limited power.

I took off the front of the intake down the filter and drove it. More airflow and power it seemed so maybe the MAF needs to be replaced. It still would not rev past 4000 once in a 4th or 5th gear though. It will rev past 4000 in the lower gears and in park. It could be the transmission I guess which would suck. I put the intake back on, it revs past 4000 in Park still. I was taking a look at this thread. https://www.clublexus.com/forums/ls-...-4000-rpm.html So I am pointed towards the MAF. But like I said mine won't rev past 4000 even with the intake off when on the highway in a higher gear. At the lower gears it did. But then once it got into OD maybe it seemed like the power was gone. Slow climb to 4000 RPM when petal to the metal.

The transmission is a little slow at first. I read some posts about how the transmission might be sluggish at first start-up. Mine is, she likes to stay in first gear at the start then shifts into second and is fine. All the shifts between gears are good. Shifting into the higher gears when she was over 4000 RPM and she dropped right away. And help would be great. Thanks.

Yamae

Have you tried bypassing the fuel pump resistor?

JohnAndic

No I have not tried this. I doubt I would be able to do it but I will look it up.

Edit: Maybe I would be capable of doing it as it seems sort of simple.

bradland

Yamae, just for my own curiosity is this inside the front fender? Tends to get hot on occasion...?
23080-50030

YODAONE

Fuel pump resistor and cover. Why mounted there?? Resistors degrade with age. Anyone have to replace the fuel pump resister? Any symptoms before failure?

Yamae

My 98 Celsior has it under the hood near the battery. You can find it easily since it has a heat sink with a top cover. It dissipates about 35W of heat and it becomes hot. (ie: 5X5/0.7=35.714 since the voltage drop is around 5V and the resistance 0.7 ohm.) You have to be careful for the heat when you do something to it.

JohnAndic

So I had the Y-pipe changed out. It had gotten so bad that even at lower RPM it seemed like I had less power. I think maybe the patched old pipe was clogged up by muffler cement. Also put a full tank of gas in it. But on the higher she was reving above 4000 again. So maybe it was the pipe maybe the fuel pump is weaker on a quarter tank. I'll have to wait and see if it comes back when the tank runs lower. thanks all.

JohnAndic

Still seems ok at half a tank.

I am not sure but I think my 98 is staying in 4th gear even on the highway. Only wants to go into OD when I am going really fast.

Sin1UZFE

Noticed in daily driving I don't go past 4k. I don't need to lol

I needed to today....got me wondering if I had this problem got to 5500 so I'm good I know it doesn't help you but goes to show how this doesn't really need to be revved up to perform.

Any codes thrown?

JohnAndic

[QUOTE=Sin1UZFE;10820431]Noticed in daily driving I don't go past 4k. I don't need to lol

I needed to today....got me wondering if I had this problem got to 5500 so I'm good I know it doesn't help you but goes to show how this doesn't really need to be revved up to perform.

Any codes thrown?[/Q

I think that is why it took me so long to figure it out. I was driving conservatively around the city, even on the highway you are fine staying under 3k. But when I tried to gun it on the highway I knew something was up. She seems ok now. One time I gun it at it doesn't rev high, the next time it does. Not sure if its a 4th gear vs OD thing or what.

I have no codes, no codes in the computer history. She's a pretty fast car, maybe I expect to much from her.