GsAddict

I would appreciate any input I get.

Long story short I had an amateur mechanic do my engine replacement on my 2000 gs300.
Everything went fine until it came to the vacuum lines. He had no idea how they went back together so he basically ghetto rigged it back together. I believe there is suppose to be metal tubing connecting some hoses together but he left it out. You can tell it doesn't look right. My question for you guys is can that cause the engine to idle rough and to misfire to the point where the check engine light flashes. Any information would help. And can anybody can take pictures of there vacuum hoses from different angles so I know how it's suppose to look like. I would appreciate it. Especially the part with metal tubing. I did a Web search and couldn't find the image I was looking for. Thank you guys in advance

Mr Jokster

iTrader: (8)

First off, welcome to Club Lexus

No, those hoses would not cause these problems, however if there's a vacuum leak, that can cause a misfire (not necessarily caused by those hoses unless one is being pinched or not attached correctly) metal tubing's are used for when a hose needs to make a sharp angled turn. You need to scan your computer and see what codes are coming up and what cylinders are misfiring. Check all the hoses and make sure they're not pinched trying to make an angled turn. If its a vacuum leak, you should be able to hear a hissing sound. A vacuum leak is pretty easy to locate with a fog test, or just take a big puff of a cigar and blow a few times through an unattached vacuum hose and see where the smoke is coming out. The code should tell you exactly which cylinder is misfiring, this can help you concentrate on what the cause is and where to look for the problem.

Most common problems of misfires are bad coil packs, plugs or wires. If the code gives you a bank of cylinders misfiring, it could be a bad oxygen sensor.

Again, get it scanned and come back with the results

GsAddict

So I pulled the fault codes with my bluetooth code reader that uses my smartphone. It came back with p0300, p0301, p0302, p0303, p0306, and p0446. Don't know what any of these mean so any help would be appreciated. And if anybody knows any possible causes and fixes it will help. I'm on a pretty tight budget right now and trying to see if I can fix it myself.

GsAddict

I really think it has something to do with the vacuum lines because of the way he slap it together not knowing what to do. I don't know anybody else with a gs300 so I really would appreciate some pics so I know how everything goes back together. I'm sure I will need to buy that metal tubing as he cut it to get a piece to put 2 hoses together. It really was a hack job.

firelizard

iTrader: (1)

http://www.troublecodes.net/lexus/

You have codes for misfires on 4 cylinders (P0301 to P0308 are cylinders 1 through 8), P0300 is "random misfire", and P0446 is "EVAP Emission Control System Vent Control Malfunction".

isfdude

iTrader: (11)

You have to follow the evap hoses, maybe one on the intake is not hooked up. Do you hear any hissing noises?

JJaySilver

I use this site to search for OEM parts to order from dealer online or eBay, Amazon, etc. but here's a vacuum hose diagram I think you're looking for. I don't know if it's easy for you to see which goes where...

http://www.lexussouthatlantaparts.co...roduct=5775646

GsAddict

So, I read today since it's a random and multiple misfire it can be because of the vacuum lines. It's not tied down to a particular cylinder. I'm not so worried that they are leaking but that could be the case. I'm more concerned that he just ran the lines from the wrong place in the wrong order if that makes sense. I'm almost sure he did because he left out pieces and now I have no way of contacting him. If I had another gs300 to look it that would help alot. Anybody in sacramento with a gs 300 have an hour or so. Beers on me. Or if anybody could post some pictures or theirs it would also help. Especially the lines running from and to the vsv and around that area. I can post pics of mine if that helps.

isfdude

iTrader: (11)

Check local part yards, take lots of pictures or check google.

GsAddict

Thanks everyone for your help. I figured out the problem and the best part was it cost less than $10. I knew it wasn't the spark plugs or wires because we changed them during the engine swap. It wasn't the coils because the chances of all 3 going out at the same time are slim. So I decided to try chevron complete fuel system cleaner. I added it to my gas tank and filled up the tank not expecting much. I then reset the cel and took the car for a spin. At first it was still misfiring for the first gallon of gas but by the time I reached the second gallon the car was back to normal. The cel hasn't come back on and the car feels more peppy than it has in a long time. I suggest you guys with high mileage check this stuff out. Make sure to get the black bottle which says complete fuel system cleaner and not just fuel injectors because it's suppose to have 2x the active ingredients. So far I'm a believer but I will keep you guys updated if anything changes.

isfdude

iTrader: (11)

Glad it worked out for you. It seems some fuel system cleaners work better than others.

Mr Jokster

iTrader: (8)

I'd still keep an eye on that p0446. Thats a common problem with the canister valve.

naluloa

Your mechanic screwed you over so hard if his vacuum hose work caused all of that.