THXDOC

1993 LS. Rescued from a snow bank. Replaced hopeless air bag suspension system with coil overs. Replaced MAF. Repaired ECU with my rebuilt unit from eBay guy with ok feedback. Replaced TPS units. Cleaned throttle body with carb cleaner. Air filter ok. Ran enough fresh gas and Seafoam thru should not be fuel quality. Throwing an HO2 sesnsor code right upstream, but I can't believe one bad sender can make a car run this slow but tell me I'm wrong, please.

Dead slow from takeoff, awful from there up to 60. Passable from there on out. Timing? Open to suggestions here, won't take offense at any idea no matter how redundant or simple. Been passed by a school bus and grain truck this week. concerned about bird-strike damage next- from the rear.

LScowboyLS

could be timing belt one tooth off on one cam, could be engine coolant temperature sensor, could likely be ECU capacitors (ebay rebuilders are notoriously awful)

if you replace the O2 sensors, you need only worry about the two on the engine side of the cats, they are the only ones that the ECU uses

make sure to replace with Denso p/n 234-4211

THXDOC

@ LS Cowboy- thank you for your informative post, a couple of things there I hadn't thought of. Here's the deal as of today- I think the guy did an OK job on my ECU boards because, he's an EE, and does this service for local Lexus dealer. Also, ECU would not produce a trouble code before rebuild and now communicates ok with OBD I tool. BUT- the newest symptom is an overwhelming smell of raw gas. Gas cap was just replaced with Stant unit, tank bungs were checked and tightened, no visible leaks or cracks in any fuel lines. Makes me wonder if an injector is bleeding out. My VIN did not correspond to recalled units for this problem which were much newer. All ears again, anything you can volunteer I will check. Would be so much simpler to have an ordinary car but I refuse. lol

deanshark

You say you changed the AFM, are you sure it's good. Your symptoms point me towards that, especially now you say you smell gas. Try unplugging the AFM to see how it runs.

cobalt91

I'm with cowboy on this one. Pull the covers off the timing belt and check it for wear. You didn't. Say how many miles.

THXDOC

Thanks gang for the replies. AFM (MAF in my lingo) was replaced by a used unit that was supposed to be bench tested. Unplugging is a great idea. Miles is 199K- will also check timing belt. After finding out how important the Coolant Temp sensor is, I will be replacing that with a new part tomorrow. THANKS for the ideas.

LScowboyLS

perhaps some would disagree, but for the most important sensor on the car, I would go with genuine Toyota on this one (and on any other part that directly affects how the electronic fuel injection runs)

THXDOC

Found evidence of past leakage around fuel pressure regulator on the driver's side. Smell gas the strongest right there also. Might be a blown regulator allowing super rich conditions at idle, which mitigates with greater vehicle speed and air volume. I've heard a fuel system can actually draw gas back around from the evap system when a regulator is bad. Going to replace both fuel regulators also. MAF was unplugged and found to be operative. New Coolant temp sensor arrives tomorrow, going to put that on also. This thing ought to run great when I finally locate the true problem, what with all these new parts. Ha

LScowboyLS

if it doesn't, let's see some high resolution pics of this ECU caps job, I would like to see visual evidence of the correct caps installed correctly

and you should never have a gassy smell, that is definitely a leak, a system running just very rich will not smell gassy with a modern catalytic converter

THXDOC

OK Cowboy, I'll shoot some MACRO shots of those caps later tonight and post.

And I agree about the leak issue, and with the amount of gas smell you'd swear there has to be a wet spot or a puddle somewhere but nothing to be found. Went over it with a buddy today at lunch, he's a better wrench than I am and he couldn't find a source either. Stay tuned and Thank You!!

LScowboyLS

you just have to start at the gas filler neck and proceed through the system all the way to the injectors, the gas just doesn't have a very complex route, so this should be relatively easy to locate!

due to the complexity, finding an electrical short is 1000's of times harder!

don't forget to remove the rear seat and sniff around the fuel pump area!

THXDOC

Here are the macro photos of the work on my boards. Looks like pretty clean work but would be interested if he used the right stuff. Thanks as always.

LScowboyLS

ummm....... that is the wrong side of the boards, silly!

THXDOC

https://www.clublexus.com/forums/images/smilies/pat.gif

LScowboyLS

that is only 5 capacitors, you are missing a few

make a list of the brand & series of each

soldering looks good as far as i can tell