UCF11R

Okay guys, firstly, hey from down under!
Secondly I recently purchased a 1990 Celsior for 2k full VIP treatment. (JDM LS400) the price I paid I expected some issues. And here they are!

It has a heating problem. Heats to halfway on the temp gauge, and motor itself feels hot. Have searched the forums and come up with several options: thermostat, rad blockage, ECT sensor etc.. I'm just after anyone else who's experienced this, thoughts.

Also it's a pig on fuel too. ECT again perhaps? Can definitely smell fuel in the exhaust. Also lacking low end power but anything above 3k and it picks up. VTEC kicked in yo.. Haha.

Starter winds but doesn't start the car sometimes? Turn off car completely and restart and usually it's fine? Definitely an issue there.


I'm not to mechanically minded so any of your guys input would be greatly appreciated

Cheers,
Scotty.

UCF11R

Also has a miss at 2k under light load, if I put my foot down its fine.

LScowboyLS

I would do the following in this order, and several of your issues will go away, such as the miss and the overheating

● clean throttle body (especially butterfly valve area)
● new temp gauge sensor (the one for the dash, $15 genuine Toyota) so you know more about the real temp accurately
● new ECT sensor (genuine Toyota - shop online for it, can be found around $45)
● new thermostat (genuine Toyota - make sure jiggler hole is at 12 o'clock)
● insure cooling fan is running (electric fan) when car starts to get hot) - if electric fan doesn't come on when car gets hot, then you need new sensor in bottom corner, driver's side, of radiator, (aftermarket is OK on this part)
● change coolant using genuine Toyota red (long life)
● new radiator cap (genuine Toyota)
● new fan clutch if equipped (JDM often have the oil based fan system, if so, change fluid and top up)
● new caps and rotors from Toyota (not aftermarket)
● new plug wires and plugs from Denso or NGK (the two OEMs)
● new ECU capacitors (yours are 24 years old, service life is ~12 years)


if the car still overheats, only then would I consider a new radiator from an auto parts store (Toyota radiator is very high cost)

all Toyota parts can be negotiated for 25% off from the dealership, if you mention that you will otherwise be buying them online - shop the online dealerships (Sewell, Park Place, Lexus of South Atlanta, Lexus Parts Now, Carson Toyota, etc.) and keep in mind that Lexus parts are often cheaper at a Toyota dealer when they cross over.

UCF11R

Throttle body clean - check
Coolant flush - check
Radiator cap - check

Throttle body clean gave me a noticeable change in power but the miss is still present and is sluggish off the line.

Will be ordering sensors, plugs, leads, caps and rotors in coming weeks. Will let you know the result. Hopefully the heating problem isn't the radiator because as you said they aren't cheap

Fan is running and is oil based system. Will change and get back to you on this also.

Any idea on part numbers for the sensors? And where they are located on the car. I have no manual. I think I have a picture of where the ECT is located but not the temp sender.




Also Speedo is not working. But rev gauge/fuel/temp all work fine? Odo has also stopped and cruise control doesn't work. O/D light sometimes flashes and T/C OFF stays on constantly.

Thanks again,
Scotty.

DreDawg81

Excellent advice !

DreDawg81

I have the FULL MANUAL for the 1990 LS 400. Original Owner did rip out a page

If you know what you looking for I can try and copy a few pages for u and send it via pdf.

I could have also sworn that I saw it posted on line some where....

LScowboyLS

here is a pic of the two sensors - the green one is ECT, the grey one beside it is gauge sensor

UCF11R

Not sure which one I'm pulling out? Leaning more towards the one on the right to replace Caps in? If so what's the other one? Haha

LScowboyLS

your photos are a bit dark, but the one on the right looks correct - in any case, it is the only one that will have literally 90 wires going to it and those 90 wires will be spread across 4 different connectors

UCF11R

Struggling to find someone willing to undertake the soldering task for me. Stupid Australian computer people