607ls400

I have started the journey to replace the starter in my 1990 ls400. I understand that I need to pull the fuel rails/injectors as part of this process. I believe the injectors are original to the car, having survived nearly 34 years and 111,000 miles. I feel it would be prudent to at minimum replace the injector to manifold seals PN#2329141010 . My question is:

Since I have the injectors out anyway, should I look into sending them out to be professionally rebuilt/cleaned/flow tested? If so, Where would you recommend? Are there any other associated gaskets/bits I should replace if I opt to not send them out?

They seem to be functioning normally, other than a strong fuel odor from the exhaust on cold starts, which could be unrelated. My goal is to give myself the best odds of not having to pull the plenum again in the near future.

Thank you for your suggestions!!

400fanboy

If memory serves me correctly, the coolant temp sensor would also be a "while you're in there", and, may contribute to excessive fuel being used during cold starts if it's "sticky". It's a bit difficult to reach in the early 1UZ motors, where in the later motors it was relocated to a significantly easier to reach location.

https://www.clublexus.com/forums/ls-...ange-pics.html

You'll also need the various gaskets for the intake and I think the coolant passage you have to disassemble (I don't have a complete list sorry), and, you should probably plan on replacing any rubber hoses\vacuum lines that are in the area as they will be brittle and likely to fail during disassembly. You might also want to consider a ignition service as well, replacing the rotors wires etc depending on their condition and on when\whether they have been replaced or not. This is not a complete list, but just what comes to mind.

My car also smells, though for me it's not like straight fuel like a gas station. It's like extremely rich exhaust (like a hotrod running rich before it's tuned) during cold start and I haven't found a good explanation for why it happens other than cold start is functioning correctly and running the car rich to protect the engine. IDK how we can define "smells" over the internet to decide which condition is abnormal amounts of smell or not. All I know is that it's "richer" than other cars which I experience in my life.

I've been here for 5 years and I've never heard of someone repairing the injectors or even of one failing if I'm honest. Not to say it doesn't happen, they aren't like a 1UZ head gasket where:if you think it's a head gasket, your tests or symptoms are wrong, because it's not. Most likely from someone running a particularly foul fuel source for a long time, rather than a problem with the hardware itself. It wouldn't surprise me if everyone on this forum is running their original injectors. It wouldn't hurt to have them serviced "while you're in there", but whether that's worth the $ to you is only up to you to decide. I wouldn't consider it necessary. I don't have particular guidance on this, so I don't know if they require special attention\procedure like the power steering or alternator does.

paulo57509

I wouldn't bother with sending them out for cleaning or flow matching. Unless there's a valid reason to do so, or you lose sleep over such things. Just replace the o-rings, etc.

I have to agree that the injectors are for the most part, trouble-free even when using non-top tier fuel. I've been running 7-11 premium (not top tier) in my '98 for ~63k miles, pretty much exclusively. Have yet to have any injector issues. When I had the fuel rail off the intake, I just sprayed off the debris from the exterior of the injectors with starting fluid, replaced the o-rings and cushion rings and re-installed them.

No issues with intake valve deposits with this fuel either. What ever the minimum detergents they add, it's adequate.

607ls400

Thank you both for your suggestions! I have ordered seals and will replace them myself. On a related note, I want to remove the cold start injector from the plenum to thoroughly clean the egr gunk out, but the gasket where it mates to the plenum is discontinued.

23293-50010 is the part #

Do I reuse it, be careful, and hope it reseals properly? Or is there an aftermarket gasket available? Maybe a liquid gasket / fipg?

400fanboy

In that case, I would suggest leaving it alone unless you have a specific problem with that injector.