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I starting this thread to document my journey of getting my recently purchased 92' LS400 running. Bought the car for 3600, with air suspension, clean bodywork, lots of cosmetics, etc. but in non-running condition. So far I have checked for spark on 3, none have spark. I have 2 ECUs, one new and one used but was working when the car died. Less than 1 month ago. The original owner said when it was parked it had a spark and it wasn't receiving fuel, it would start and run for a few seconds when starter fluid was sprayed into the intake even after a replaced fuel pump it didn't work. Though when I got it I tried starter fluid and there was one time when it almost started but didn't quite, after that no success. So it looks like I've got a fair few problems on my hands. Hopefully, I can get it up and running eventually, and I will try and document all successes and failures with help from you guys possibly . No CEL light either by the way.
How many miles are on the car? It definitely sounds like a no spark condition to me. Maybe you need to check the coils. Hopefully the distributor caps and rotors are also ok. Has this car ever had a timing belt service, and have the caps and rotors ever been replaced?
Hoping that it's just something like one of the coils. The coil located on the bottom of the driver's side of the engine is more prone to failure due to heat.
If it turns out to be that the distributors are not working, that's a much bigger job, but it's less likely that it's your problem.
How many miles are on the car? It definitely sounds like a no spark condition to me. Maybe you need to check the coils. Hopefully the distributor caps and rotors are also ok. Has this car ever had a timing belt service, and have the caps and rotors ever been replaced?
Hoping that it's just something like one of the coils. The coil located on the bottom of the driver's side of the engine is more prone to failure due to heat.
If it turns out to be that the distributors are not working, that's a much bigger job, but it's less likely that it's your problem.
It had 200,000 miles on it. I’ll check the coils asap and post my findings. I believe it has had a timing belt done, not too sure about the caps and rotors ever being replaced
How many miles are on the car? It definitely sounds like a no spark condition to me. Maybe you need to check the coils. Hopefully the distributor caps and rotors are also ok. Has this car ever had a timing belt service, and have the caps and rotors ever been replaced?
Hoping that it's just something like one of the coils. The coil located on the bottom of the driver's side of the engine is more prone to failure due to heat.
If it turns out to be that the distributors are not working, that's a much bigger job, but it's less likely that it's your problem.
Hey, I checked the ignition coils with a multi meter,
im getting 50 ohms reading on the screen (sorry if i’m reading it wrong but that’s what my grandpa told me it was reading as well). I’ve been looking at other forum posts and i’m seeing people say it need 13,500ohms? Should I purchase some new ignition coils for the car or am I reading my multimeter wrong?
Hey, I checked the ignition coils with a multi meter,
im getting 50 ohms reading on the screen (sorry if i’m reading it wrong but that’s what my grandpa told me it was reading as well). I’ve been looking at other forum posts and i’m seeing people say it need 13,500ohms? Should I purchase some new ignition coils for the car or am I reading my multimeter wrong?
There are two resistances to check per coil module. The resistance of the primary coil and the resistance of the secondary coil in each module.
Note the positions of the multimeter leads in the following diagram.
It sounds like you might be checking the primary coil. 50 ohms would be out of spec unless you mean 0.50 ohms.
There are two resistances to check per coil module. The resistance of the primary coil and the resistance of the secondary coil in each module.
Note the positions of the multimeter leads in the following diagram.
It sounds like you might be checking the primary coil. 50 ohms would be out of spec unless you mean 0.50 ohms.
Excerpt describing the inspection process:
I was infact checking the primary coils and i’m pretty sure it was 50ohms on the ignition coil on the top and then 76ohm on the ignition coil on the drivers side, but i’ll double check with a better multi meter if it was reading 50 or 0.50 but i’m pretty sure it was 50. I’ll also check secondary coil resistance and get back on that too!
Today I went back with a different multimeter and the distribution coils both primary and secondary are in spec. I went over the fuses and found the ignition fuse was blown, I’ve replaced that, nothing different. I also replaced all the spark plugs as they looked pretty old. I replaced them with NGK Iridium IX. While replacing the spark plugs I also realised all the wires seem to be in the wrong places. They are all too long or too short, just fitting. So I’ll probably do that soon. Not really where to go to next door I’ll probably look over other threads and try see what else I can do.
The distributors and spark plug wires should be checked to see if spark is making it to the cylinders. If the distributor cap or rotor have failed, then spark won't be distributed to the cylinders. But this should be tested first before pulling it apart, since caps and rotors are a fairly big job compared to spark plugs..
Also be careful not to flood your engine with fuel, since there is no combustion going on. May be worth removing the fuel pump relay while you test for spark.
Last edited by CELSI0R; 09-21-22 at 06:35 AM.
Reason: Changed video to similar setup instead of coil on plug
Was that first video supposed to be a joke? Checking for spark while engine is running? He's got all 4 coil on plug wires loose. The one he checks is just flopping around.
The title is "how to check spark plugs and ignition." He didn't check any of the plugs, he just used an old plug so that only proves the coils were all good.
The way to check it right would be to pull and use the plug of the cylinder that you're checking the wire for spark. That way you know you have spark all the way. And yes, always pull the fuse for the fuel pump so no fuel gets sprayed in the cylinder while you're cranking the engine. Have a helper crank the engine while you're watching for the spark.
Last edited by deanshark; 09-21-22 at 05:20 PM.
Reason: Video was changed
It wasn't a joke, but I changed the video to one with the same concept, instead using a distributor with coil versus coil on plug setup. Just with the plug wire and cranking the engine near a ground
By doing this, OP will need to prove that the coils + distributors are working. I would expect this to not work, as OP mentioned that there is no spark on at least 3 of the cylinders.
Yesterday when I was doing some recommended testing. I found I have a short somewhere in my ignition. Not a clue where to go from here. Dumb idea but I replaced the old fuse with an Amazon fuse and it started sparking like crazy, completely melted the plastic on the fuse, fuse didn’t pop and i had to pull it out with pliers. Major smoke coming from my fuse box and so in a panick after pulling the metal fuse that didn’t pop, I disconnected the battery fully. Everything else on the car works fine so far from what I have seen, but I need to figure out how to fix this short next I believe
Below i’ve attached a photo of this crappy amazon fuse. Never again.
Yesterday when I was doing some recommended testing. I found I have a short somewhere in my ignition. Not a clue where to go from here. Dumb idea but I replaced the old fuse with an Amazon fuse and it started sparking like crazy, completely melted the plastic on the fuse, fuse didn’t pop and i had to pull it out with pliers. Major smoke coming from my fuse box and so in a panick after pulling the metal fuse that didn’t pop, I disconnected the battery fully. Everything else on the car works fine so far from what I have seen, but I need to figure out how to fix this short next I believe
Below i’ve attached a photo of this crappy amazon fuse. Never again.
Finally got the car running. Bought good fuses, swapped every fuse out, new ignitors, replaced those. Fixed my issue and I was getting spark, didn’t get fuel at first, went and got a new fuel pump ECU. ANDDDDDD she runs. but really rough. I’ll idle at roughly 500rpm, it will slowly fall and then rev up to 2.5k fall to 1k and slowly fall down again, gonna check vaccum hoses.
I also need a new rubber neck for around the intake onto the engine as i ripped mine pulling it off to change plugs, anyone know where I would get one of those??
Project is far from fixed. I have a leak in my air suspension as of right now on my front left, and my controller is acting all wack, car wont air down, front right wont air up at all, so I think i’ll just end up buying a new controller and fixing that
Attached is a photo of the car as it sits now
Thanks for all the help solving my mystery problems and i’ll keep posting my journey along here.
09-05-22, 01:44 PM
92' LS400 Crank, No start, My Journey.
. No CEL light either by the way.
Checking for spark while engine is running? He's got all 4 coil on plug wires loose. The one he checks is just flopping around.
