488civ10

dear CL guys/gals,

i have a weird engine sputtering/ stalling problem that is intermittent. it happened once last summer while my wife was driving it, then it went away. happened to me once in february 2010, but i put it into neutral, gave it some gas and the rpms roared and the problem was gone. my dad borrowed it last month, it sputtered again, with the rpms going from idling speed to almost stalling a few times, before it died completely. this problem was repeatable, and after he restarted the car, it did the same thing three times. so i had it flatbedded to my mechanic, and of course... he was not able to replicate the problem.

yesterday, it was a pretty hot day, and with the a/c blowing and on my last stop of the day, getting ready to head home it finally happened again. when i step on the gas pedal, it doesn't do anything while it's doing the sputtering, stalling thing. i fully floored the pedal several times and still no response. i then popped open the hood to take a look at the engine as it was doing this (and tried slapping the IAC valve to no avail), and saw the entire engine shaking and shuddering a lot. anyone with a similar experience, or any idea what it might be? i searched the forums and saw some mostly SC300/400 posts with this problem... one which a new distributor rotor was the culprit. however, i had that changed in january. being that i'm not mechanically inclined past oil, spark, trans/diff fluid changes, i'm worthless in the DIY department. anyway, any help/suggestions would be welcome. just want to have an educated stance before i call two local mechanics that have come highly recommended by two of my friends.

cheers,
488civ10

BrittonJ85

From my experience when my car kept cutting off while driving.....

I replaced, my timing belt, right cam, spark plugs & wires, distributor cap & rotor, oil change plus new filter, new transmission filter and flush, coolant flush, throttle cleaning (dismantle and re-mantle) injector cleaning and power steering pump and pulley. Just to figure out what the problem was.... Which I would have saved time and money if I would have purchase a repair manual but at-least I have new parts under the hood sense the car is about to hit 200k within Friday.

What I will recommend for you to do, is check the spark plugs, wires and replace you're fuel filter. Those 2 caused my issues with the car stalling and sputtering. I had to change my spark plugs twice because the ones I bought before were too cheap and faulted out within 2 weeks so I bought NGK-R which did the job. The car stop sputtering, shaking but staled again until I replaced the fuel filter which was too bad.

Don't forget to get a repair book but if you are not comfort working on you're car take it to a mech that is certified working with Toyota/Lexus.

vaughn37

I have been having similar problems. It only does it to me after I have ran the car hard.
I cleaned my air meter .But i have not ran the car hard since. also each time it done it my tank was close to empty, so maybe it is the fuel filter.

LiCelsior

iTrader: (32)

does sound like a ignition related problem. check resistance of your plugs and ur ignition coils.

488civ10

hmm, forgot to say that i had new oem sparks, wires, rotor, cap all installed in february. now i'm just trying to get my wife to recall if it did the stalling/sputtering on her last summer, or if her memory was wrong and that it actually happened after the big repair/maintenance bill i shelled out in february.

i appreciate all the suggestions and replies. may take me a while, and i'll check with a few new mechanics perhaps for some estimates.

488civ10

oh yeah, the one idea my mechanic did have was that it could be the ignition coils. but after 4 weeks of my car sitting in his garage, that possibility wasn't explored, and the reason was because he couldn't get the car to sputter. is the only way to check if the ignition coils were the culprit to actually install a new part and that it had to sputter?

LiCelsior

iTrader: (32)

well u can check if its in spec.

BrittonJ85

I would double check the spark plugs. It doesn't hurt to have them replaced again but defiantly get you're fuel filter replaced. Once I replaced my spark plugs, the car stop sputtering/misfiring and once I replaced the fuel filter, the car stop cutting off. It would even cut off if I tried to do a burn out.... It's not that hard to change spark plugs and fuel filter but I wouldn't recommend if you aren't too sure but it shouldn't cost you much to have a mech do it. But do take it to someone who won't hassle you or you're time.

J Ritt

488civ10,
I've been having this same exact problem with my '92, and it's driving me crazy! The car just completely dies during acceleration...then all of a sudden it will 're-engage' and take off...then it will become completely unresponsive to throttle inputs again. It's a cycle of surging and dying. If you park it running while this is happening, it will idle okay for a few seconds, then RPM's will drop very low, the car will sputter but usually not shut off...the engine shakes, quivers, etc, then the rpm's shoot back up over 1,000 rpm's....then it settles in at idle...rinse, repeat.

The first time I had it happen was a couple of years ago, right after I bought the car. I was sitting in LA traffic for a long time on a hot day.

It happened again once last summer.

This summer it has become more frequent...has happened probably 3-4 times in the past three months.

I've finally decided to try and fix it, since it's put me a couple of bad situations on the road recently, and I don't want my wife driving it.

I've been struggling to find commonalities between these events. Here's what I've come up with:
1. It only seems to happen in warm weather. I've never had this happen during mild weather. It's been extremely hot and humid this summer, and the frequency of these events has increased substantially (obviously could be a coincidence, or the condition is just getting worse).
2. I think my fuel level has been roughly 1/4 tank or less every time it's happened. I'm not 100% on this one, but I believe I've been on the lower end of a tank each time.

I think I'm going to try changing the fuel filter first. I'll have to check my records, but it may be due for plugs & wires as well. I'd like to do only one thing at a time though, to try and isolate the solution.

Thanks,
jeff

JimsGX

J Ritt,

I have the same problem on my 91 with 95k miles. It is related to the hot weather and the amount of fuel that's in the tank. There are plenty of posts on here about the same issue, but no one to my knowledge has definitively come up with an answer. One post I saw not too long ago talked about a fuel resistor or capacitor under the hood (not sure where, maybe on the passenger side) that works in conjunction with the fuel pump. Capacitors tend to start to fail over 10 or 15 years so it wouldn't surprise me if this is the problem. My guess is that the additional heat that's building up under the hood in conjunction with the amount of fuel that's in the tank at the time, is causing this fuel capacitor / resistor to go flaky on hot days. A replacement is available for this part. IIRC, the OEM part was in the $150 range.

vaughn37

the fuel pump is cooled from the gas in the tank. So maybe being low on gas caused the problem.

My car does not have the vsv fuel pressure control.. this keeps the car from vapor lock
I will reinstall this part.

also maybe the pulsating damper is getting old and not working properly.this reduces fuel pressure fluctuations .

I have tried 3 times to change my fuel filter.I can not get the rear line to come loose. It starts to loosen then binds up and I do not want to force it.

J Ritt

Thanks for the responses guys. I scoured this board after the very first time it happened, but came to the same conclusion that there was no definitive answer. I was hoping that by now someone had sorted it out. Apparently, not completely!

I tried to take note as closely as possible of the condition parameters on the heat and fuel situation. I'm just glad I'm not crazy!

The one thing I am continually surprised by is the amount of pressure in the gas tank every time I open it for a refill. I've never seen another car quite like it. It practically blows the lid off when you get down to the last two threads while unscrewing!

In the name of science, I guess I'll just hold off on the fuel filter swap, and try to keep my gas tank above half for the rest of the summer. I'll report back.

BrunoMolly

I am having the same problem....When I bought my LS400, a 1993, it had been sitting for 3 years. It had very old gasoline in the tank. The old fuel pump was rusted and locked up. The fuel pump was changed but not the filter. Car ran fine once the old gasoline was sucked out of the tank and replaced with new fuel, pump and filter. I changed the filter again last week and it was full of rusty dirty looking gasoline on the intake side of the inline filter. I suspect the Strainer in the tank is partially gummed with residual Varnishy gasoline from the bottom of the tank. I have run a can of seafoam thru it about 4 months ago.
Have been driving the car since December of 09. This is the 1st summer I have had with this car and its not pretty. The engine will heat up at traffic light with the AC on. I can turn the AC off and the guage drops down to normal in less than a minute.. While in motion with the AC on not a single problem. The AC will chill a can of beer on the highway and engine temp needle stays 1 hair above the mid way point. This past winter I changed the thermostat because the engine wasn't getting hot enough...Imagine that...
I wanted to drive this car and learn it. So since it has run fine since I have put it on the road, I want to start changing things 1 at a time to see what fixes what. That IMO, is the only way to NAIL this problem and Post back so that everyone knows what to do. I have the same symptoms that Land people to this post.....
HOT DAY- Power loss, engine sputtering, skipping like its running on 1 bank of cylinders....
I can see that changing the plugs and Caps based on reading makes the car run better, but doesn't fix the problem in MOST...Not all, but most cases.
I would think a misfiring engine would generate a CEL (Check Engine Light) from the Knock sensor...such is not the case as I haven't heard anyone mention this....
Sounds to me like Low fuel pressure for whatever reason. Here's my take on this:
-My LS runs Worst the lower the Fuel level, like less than 1/4 but not Low fuel light on yet...Like it's starving for fuel...The Same way it does....WHEN IT'S HOT! So...either the ECU is not allowing the fuel pump ECU in the trunk to run at full speed when its Hot to keep up with Engine demand for more fuel, (90-92 1st gens don't have FP ECU's) Or, with Low fuel in the tank the pump heats up, or there may be some Cavitation somewhere on the delivery of fuel thru the line with low fuel..hell I don't know....
-I can put in 20 bucks of 87oct and it runs great, Much better...lots of power! So there goes the "Ignition" theory...
In my case at least..
My plan.....instead of Easter Egging a whole bunch of ***** all at the same time, I am going to change things 1 at a time to see what fixes this problem.
I am starting with my FREE NGK-R Plats I just got from Autozone...(Reward card redemption).
I'll post back later this weekend. Oh..I have no problems at all at night, with the ac off. Car runs great mostly all the time at night when its cooler like 80 degrees and below on the dash cluster....but still gets a little sluggish when the level get down to 1/8 tank... I miss the old 280ZX with the little gauge under the fuel needle that went from 1/8>>> 1/16 >>>> 1/32 of a tank of fuel down to 0/0...Thats just d@mn insane to have that kind of information knowing you got 100 miles to next gas station!!! Lol!
I holla back later kats..

DanF

I had the same problem today...i think im going to try changing the fuel filter and pump

488civ10

JRitt, thanks for the post. An update: I actually had the fuel filter replaced this February, so that's off the checklist. I will pledge to update my situation as it develops and I hope others with similar problems do so as well. Unfortunately, I've been busy with so many other things, I haven't even gotten around to my beloved LS, except for that I dumped a can of Seafoam in the gas tank a few days ago. I also read on another forum that someone had a better experience with Valvoline Total Fuel treadment which was 7 bucks at my local Kragen, instead of 10 for the Seafoam. Perhaps after one tank of gas is used, I'll go another without additives, then on the 3rd tank dump some of that Valvoline stuff in. BTW, does anyone else think Seafoam smells kind of good?

My tank was about down to 1/3rd the last time it happened, at the end of the day as I mentioned, and pretty hot out. Another weird thing that I've noticed that's been happening in the past year is that the fuel gauge drops very quickly in the first 25-30% of it's reading (overexaggerating the amount of fuel consumed). Anyone getting the same thing?

Another thing I haven't mentioned about my car is that if I drive stop-and-go in the city, the mileage isn't that great, sometimes as low as 15, but usually around 16. However, my freeway mileage averaged a whopping 26mpg with the A/C on almost the whole time, going 80-90 back down to SoCal from San Francisco. This was after my former mechanic changed out the plugs, wires, rotor, cap, cracked egr pipe, etc. I had been getting 23mpg highway previously, so that had to make a difference. Plus my acceleration and engine smoothness both were alot better than prior to the replacements. Odd that the stop-and-go driving didn't see any improvement or change (and even went down a tad).

About all I can say for now. I haven't opened up my air intake yet to examine the MAF sensor (idea that over oiling K&N on mechanic's part could have screwed it up). But I figured out it's the Karman Vortex type MAF and the CRC MAF cleaner spray that I bought cannot be used. Not sure what line of action to take moving forward, but I've read about O2 sensors, coil packs (don't even know where or what the heck they are), ECU, fuel pump, etc. I love this car too much to move on, even though leasing makes a whole lot of sense to me now.