Epigy

About a month back, I purchased a 1993 LS400, and when I bought it, it had a throttle issue. If I pushed down too hard on the throttle, the car would lose all power until about a second after the throttle was released. Figured it was the TPS, and put it off. Had to replace the battery because it was completely dead. 6 year old battery, made sense it was bad. A few days ago , on the way to work, and the car dies on me. Start it back up and it was in Limp mode. Still in the neighborhood, drove it back home. Friend suggested cleaning Throttle Body and MAF, so I bought cleaner and completely cleaned it. While cleaning it, something broke next to the MAF, a plastic nipple connected to a rubber hose. Not hard to miss, right on the intake pipe, although starting it that night it made no weird noises in idle, and had no issue starting. Started it up the next day, completely fine, no issues, no weird noises. Car was driving better than ever, throttle issue still existent, but was less noticeable. Got to work with no problems, car felt great. Car starts right up after work, when I put it into drive, I notice the lights in the car and the headlights dim slightly. Driving home, about a half mile away, in a neighborhood, car dies, completely. Everything shuts off. Try starting car back up and it starts but barely, takes longer than normal. Go to put back into drive and the second I do, the car dies again. Everything shuts off. Try it again, this time shifting into reverse, works fine, and I back it to the side of the road and park it. Walk home. Next day, friend comes to check it out. Car starts just fine, let it sit for a minute and try going into gear. Works at first, but while waiting for traffic at a stop sign car dies again. No more than 20 meters from where it was parked. Try turning it back on, dies again. Tried shifting into low and 2nd, still dies. Start it, try putting it in reverse to park it again, and it dies immediately, same as it would in drive or any other gear besides park and neutral. Friend straps car to his and pulls it back home. That was yesterday, and I can't find a fix to this. Repairing the broken piece ASAP, but figured it wasn't related to the issue since the car was fine the morning after it broke.

dicer

First off, you do not clean the air meter on a gen 1 in most cases it just ruins it. So if you want a new one its 700 bucks, so what ever the original problem was or is, the air meter is very likely now no good.
Dying when put into gear can be a loose connection or bad wire that gets pulled apart when the engine moves from a load being applied to it.
And when you mention head lights dimming etc. I would be looking for bad battery and fuse connections, also check the alternator how much voltage is it putting out?

deanshark

I agree with dicer. The AFM should never be cleaned, with regular cleaner that is. There is a special cleaner and way to clean it very gently. If you search for "clean AFM" you'll find more info on it. But, either way your stalling problem sounds like it would be from a bad AFM anyway. My 93 did the same thing. And it usually doesn't throw a code until it's unplugged. I unplugged mine and the car was a rocket. When unplugged it runs extremely rich, which will kill your O2 sensors and eventually the catalytic converters. If you unplug it don't run it too long like that. A used one is about $50 to $75 at a junkyard, if you can find one. Make sure to bring an ohm meter so you can test it before you buy it. Of course test yours first to see if it's bad. Your lights dimming sounds like the alternator going, or gone, bad. Or the battery connections are loose from when you changed it. Are they dimming when you press the brake pedal? That would point to the alternator.

Oseberg

After checking your AFM, if it's still good, check the fuel pressure. You might have a clogged fuel filter.

You should be able to borrow a fuel pressure gauge from a local auto parts store.

Epigy

What cleaner would you specify need be used? I used MAF cleaner on it. Also, no, when the lits dimmed it was a one time thing when the car was put in gear. It didn't happen again when I pushed on the brake. I haven't been able to test it any more than that as I can't even get the car in gear anymore.

deanshark

Personally, I wouldn't use any cleaner b/c I did on my 93 and then it was no good. Expensive lesson for me there b/c it didn't have a code so I changed all kinds of different parts trying to find the problem. So now, with my 94, I will only use compressed air to clean it, when I get around to it.
What do you mean by you can't get it in gear now?

Epigy

The car will start, but roughly, smokes excesssively, but will idle in park and neutral. Once it's put in Reverse, Drive, 2nd, or Low, the car dies. Everything shuts off. And it's not when I try to accelerate, even if I keep my foot on the brake while it's in gear, it'll still die. Takes maybe a second after putting in gear. But then it'll start right back up afterward, and it'll be doing the exact same thing.

deanshark

What I said do the lights dim when you hit the brake, I meant when you step on pedal to put in gear. If it only happened once then it was probably when the car was about to die and the RPMs dropped. (Less juice going to lights) That little plastic nipple thing that broke you might be able to just super glue it back on. That's what I did when mine broke off. But don't plug the hole with glue. Plastic gets pretty hot and brittle over the years. Did you unplug the AFM yet to see if it runs better?

Epigy

Yeah, I've got the stuff to reattach to piece, and I'm going to ASAP. I haven't had time with work and all to go through with the diagnosis. I'm getting the car towed on Friday, so I can take it to the shop I'm at. Once it's there, that's when I'm going to run through all the steps.

deanshark

Just a thought

Before calling a tow truck you should just unplug the AFM to see if it runs right. If it runs then you can drive it to the shop if needed to diagnose. It only takes 2 seconds. Right on top and in plain view. Can save you the price of a tow, which you can spend on parts you might need.

Epigy

I would give it a try, but the alternator is out of the car, and it's raining out right now, kinda badly. So I can't go reinstall it for testing. Supposedly going to be for a few days.

Oseberg

Use a battery charger to charge your battery while it sits in your driveway in the rain.

What color is the smoke?

White = water
Blue = oil
Brown = fuel

Epigy

The smoke is white, and all my equipment is at the shop.

Oseberg

White = water

You might have a blown head gasket.

You should check your spark plugs to see if one or more of them are unusually clean. You can also remove the radiator cap and check for bubbles in the coolant. Also, does the coolant level change when you rev the engine? Are any of your spark plugs unusually clean, or even wet? If you remove the radiator cap, does the engine run better?

Years ago someone gave me their junk car and I drove it for several years. After about a year, I noticed that the radiator cap seemed loose. I went to get a new one that fit tighter and then the engine ran like crap. It turns out it had a blown head gasket and the proper radiator cap was causing pressure to build up in the cooling system which in turn caused more water to spray into the cylinders than the engine could handle, so it barely ran. With the radiator cap off, or with the incorrect cap that didn't seal no pressure would build up, and it ran fine. Since the car was crap anyway, I just left it with the bad radiator cap and kept driving it for several more years.

Anyway, do these tests to figure out if you have a blown head gasket.

Oseberg

There's also a kit that you can use to test the coolant for traces of exhaust. You might look that up.