Spawn88

İ cleaned up the 2 cam angle sensors , but i couldnt find the lower crank angle sensor . İs it located a little right top of the main crank pulley? Attached to the block veriticaly? Can anyone upload a photo please?

İ still have EFİ NG on diagnostic mode with EFi 41 message on the cluster.

Yestarday strangely car became normal in the morning and accelerate like jack russel dog but anfter i arrive stop the engine and start it again car started to do same problem.

Somewhere some cableing is messed up i think. But i couldnt find it where.

Suggestions?

usoff89

iTrader: (2)

I'm surprised nobody has suggested that it may be an ECU problem.... These older Lexus/Toyotas are known for the Capacitors in the ECU to start failing and cause all sorts of weird problems. I know its a pretty common problem in the SC400's and the LS400's. Just something to consider.

k7q

iTrader: (37)

Bump. I have the same problem car can't pass 4k rpm. 92 400 5spd.

car was running fine. Then did a 5spd swap broke in the clutch, drove a little hard and won't pass 4k rpm.

have rush headers and straight pipe.

no CEL.

xtra

Good day
Sorry, I quickly skipped through the post so I might be asking question answered already.
Was the car ever running right or did it always have the issue since you got it?

If you were to start the car and while in idle rev up, will it pass 4000 RPM or does it just die?

When reaching 4000 RPM, does it bounce up as if there is a rev limiter or does it just bug and die?

Bouncing off 4000 RPM would normally indicate an issue with electrical component such has bad sensor or bad relay/ECU , however , bugging at 4000RPM would refer to a mechanical issue/vacuum problem.

Look under the intake pipe, the black one before making the 90 into the elbow. There is an air surge tank there. Toyota has it held in plate with some type of glue. Please check if that piece is broken or cracked causing all the air to escape after the MAF.
Also please check your fuel filter, a bad fuel filter can cause a fuel starvation that can also lead to a limitation in the RPM.

I hope any of these suggestion helps.

I will think of more and update the post.

K7Q, that goes for you as well.

k7q

iTrader: (37)

just swap the ecu and still the same problem.

bouncing at 4k rpm. going to check the fuel filter next.

ronev

any solution to this?. I'm having the same issue. I opened a thread called limp plenty of spark

k7q

iTrader: (37)

found out that my RPM guage was messed up. i installed a SAFC and according to the safc im reving to 6k.

racersky

iTrader: (2)

interesting I might have to try that. I'm having the same exact problem with my car and i cannot figure out why it's doing it. I tried replacing the ecu, igniter. I have new spark plugs and wires waiting for a day i can install it, I checked the AFM and it's clean, changed my o2 sensor, and that's all i do as of yet. It definitely pulls like a healthy v8 should but just won't go pass 3800 to 4k. I think my gauge is probably off like you k7q but i have to wait to rule that out.