Which is better? I have 2 1990's one with LH2.4 and one with LH3.1. What is confusing is that after pulling some parts from a 1993 realized that it was a LH2.4. So LH3.1 wasn't a total change over.

Theoretically, the higher the version number, the more advanced, or better, the system should be.

In practice, I don't know that 3.1 is a quantum leap over 2.4. The only fundamental difference in makeup that I know of involves the AMM. LH 1.0 - 2.4 use a hot wire sensor, while 3.1 uses a hot film. I would *guess* that a hot film is a bit more robust than a hot wire.

This era was a mixed bag of LH versions (and Regina, too.) Turbos and NA motors did not change over at the same time, either. Best to look carefully at part numbers when you're grabbing stuff.
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Speed Racer, '83 240 R, '74 164 E, '93 940 OL1 (Manchester, CT)

I think the other additions of the 3.1 system were the change from a throttle switch to a throttle sensor (which relayed info on the position of the throttle at all times - not just at idle and full open) and support for air injection, which I believe was limited to California cars.

Jason,

While we are on the subject of AMM.

Is there any cleaning that be done to the AMM or maintenance.
When I removed my air intake hose (the black acordeon hose that goes to the TB), I saw some wetness on the AMM (there was some sort of circular shape grid there). Should this be wiped up? Is that some of the gunk from the TB that made it's way to the AMM.

For now I have left alone my AMM...
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'89 244DL M47 158K miles

No, typically you don't mess with the AMM unless it fails. It has a burn-off feature - when you shut the car off, it superheats the element, burning off any contaminants. Some people have used a Q-tip and a bit of cleaner to wipe off their sensor wires, but only after they became contaminated from a catastrophic oil leak. I wouldn't bother with with yours.
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Speed Racer, '83 240 R, '74 164 E, '93 940 OL1 (Manchester, CT)

Hi Yama,

Have you removed your injectors yet?
I want to do the same in my 89 which has the LH 2.4.
I have read the FAQ. One think I don't really understand is once the injectors are all out (some say to leave the fuel rail on?), how do you clean the injectors? Not just the outside, but the inside. If you use for instance Techron, how do you run the cleaner through the injector?

In the FAQ, I also saw that the injectors can be cleaned without removing them by pouring the Techron through the fuel rail via a hose, but where do you connect the hose? Not clear to me.

I'd be curious to know how you went about cleaning your injectors.
Thanks in advance for sharing your experience.
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'89 244DL M47 158K miles

Hi guYom,

I have removed the injectors. Removed the fuel rail and then pulled each injector out. If I wasn't under the pressure of a failed emissions this is a job for warmer weather and outdoors. Working with gasoline is best done outside with the extra ventalation. A good way to do this might be to grab a spare set from a pic and pull and send them out to be flow tested, cleaned and resealed. Have seen prices that range from $11 to $25. Then just swap the old ones for the cleaned ones. Next time around just send the spare set out again. You could clean them at home but keep in mind you need to be able to provided presurized solvent, electrical signal for the injectors and jars with flow measurement capabilities. Thought about making a cleaner for home use but its a bit involved. Check out the link for an example of a professional cleaning. Don't know anything about their service but their prices are good and the illustration informative.

http://www.cruzinperformance.com/injsteps.html

Thanks Yama.

What about you. Are you cleaning your injectors at all? Or just replacing the seals for now? Is that the first time you are doing this in both of your cars? My 89 244 has about 10K more miles than your wagon, I think I am due for injector cleaning.

The price you quote for 11 to 25USD is per injector and not for the whole set of 4, right?

Thanks for the link, I'll check this site. Good tips about getting injectors from a pick and pull and sending them in for cleaning.
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'89 244DL M47 158K miles

The car that got the seal change was my 1990 sedan 277K miles. (never touched injectors) What I did and the only reason is that it failed Nox emissions on 2nd try. Went to local pic and pull and grabbed an 1993 143K intake manifold injectors attached. Ordered injector seals, intake gasket, throttle body gasket. The cleaning I did was to soak the injectors in some carb. cleaner. Don't really think this did much if anything. Probably should have sent them out. Changed both seals and cap on injectors. When pulling intake noticed that cold start injector was leaking and the intake gasket on the bottom. The new intake has no cold start so that won't leak again. Hoping that this gets me through emissions. Well car runs fine now but it did before but I still get code 2-3-1. Think I'll dump a can of techron and some prem. gas in.

The charges for cleaning from Yama's link are as follow :

CHARGES:

Flow Test Only, no disassembly or cleaning...............$5.50 per injector.
Complete Flow Test and Cleaning.............................$11.00 per injector.
Replacement hoses for hose end injectors..................$4 per injector.

Cleaning looks very thorough on their Web site at least... don't think I can do that at home !
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'89 244DL M47 158K miles