tysilk

Hi all,

Long time reader, first time poster. I have seen similar issues that are like mine but i thought i would try my luck. History: Vehicle seeded for 2 years. Had smoking and misfiring issue. Ecu was replaced (with refurb) and "exhaust system cleaned" according to history. Full tune up - timing belt, fuel delivery, the works.This was at ~50k miles.

Now, at 93k miles, refurb ecu goes out. Fuel injectors dumping gas, exhausting smoke with strong fuel odor, fuel in oil. At home with a close friend who wrenches well, replaced oem ecu (thanks to the super lucky deal on ebay) and changed oil and filter. This fixed the gas dumping. Also, replaced the spark plugs as noted by obdi p03 codes. Replaced all fuel injectors with new denso fi.

Misfire continued, smoking subsided. Timing looked good. Replaced both caps and rotors and spark plug wires. Even replaced air filter and battery.

From there, it warmed up still slightly misfiring. After a ride around the block and once it reached operating temp, it began smoking white, no gas smell. Also begin bellowing up in engine bay. When idling, it jumped/misfired a lot almost stalling out.

In defeat, i am towing it for diagnostics tomorrow. I will check coolant levels and PS and vacuum hoses as well. Any thoughts otherwise are appreciated. Hoping for the best. I will let you know the prognosis and, hopefully, eventual resolution.

Thank you for your time.

dicer

Any codes? At least with a 97 you get a lot of real time info with a good scan tool. Smoking white? What is the smell? A proper diagnostic should start with a compression test. Let us know what happens.

tysilk

Thanks, Dicer.

Got a call from the shop and the compression test was fine, thank goodness. They basically let me know that the cylinder 1 misfire was from a bad injector. I didn't think that it would possibly be that seeing as how i personally changed the injectors with NIB OEM Denso fuel injectors so i brought in the originals and they plugged one up and test drove it about ten miles and now it is all better. No misfire, no smoke. I will confirm after i pick it up this afternoon or tomorrow.

Long story short, LS400 friends, if its blowing gassy white smoke, probably a bad ECU(blown capacitor(s) internally). If, after you change the ECU, it is still blowing smoke that smells neither sweet or like fuel, then i would look at the fuel delivery system.