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| New 96 metro! 17mpg :( help?; So it has a couple issues, let's fix em! | |
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| Tweet Topic Started: Dec 6 2011, 11:41 PM (2,094 Views) | |
| merlot566jka | Dec 6 2011, 11:41 PM Post #1 |
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Engineer
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Ok well I got this car on Saturday for $850. It's beat up, body damage everywhere, runs like garbage and has electrical issues. My kinda car! Anyway, first thing I did was pull the air housing off, clogged K&N... Yummy Cleaned it up, saw a ton of oil in the air cleaner from the pcv. Bought a new pcv. Checked the timing (on a 96... Wasn't sure if I needed to jumper anything so I did it by ear after staring at the timing light/dampner and seein 0* advance) Then I tried to drive it home. Couldn't accelerate.. Wtf. 3rd gear Pedal on the floor and all I get is 55mph. Made it home and decided to check it out. Advanced the timing almost as far as it would go, ran better, but idles really low. I pulled the plugs and replaced them with some new NGK TR55s I had laying around from various other projects. No change. The old plugs were pretty carboned up. I turned the throttle stop to help the RPM at idle and went and bought a whole throttle body assembly from the salvage yard that looks completely new... It's sitting in the back seat. The car ran decently so I drive it to work yesterday and today. I can get to 70mph if the wind is just right :/ Today I decided that the 2 codes on the PCM needed attention. One was for the IAT and the other for no signal from bank 1 O2. So I got a new O2 and plugged in the IAT. When I looked at the exhaust I saw some handy work to say the least. I shook the cat and got a rattle. Decided it needed its guts removed. I cut the pipe before and after the cat. I saw the double walled down pipe and decided I should replace that while I was in there. Lucky me, I snapped both bolts. So I am going to use the left over sections of pipe from my Corsa exhaust on my LT4 Vette. 2.5" down pipe! Lmao. Whatever, it's going to funnel down back to the stock soda straw size after the down pipe. So the first 7 gallons of fuel has netted me 17mpg. It's running pig rich. I will do a compression check tomorrow. And if I can get to it, clean out the egr and install the new tb. What else would cause it to run so damn rich? When I replace the O2, exhaust and tb, is there anything else I can check while I'm in there? Where can I find the pics of the timing belt alignment marks? (slightly suspect) This may be my first post... I registered a couple years back when I had a 94... That was stolen, now I have moved, gotten out of the military and have another geo. Some back ground: I have been wrenching for 13 years. I have a corvette and an m35a2. I am an engineering student. Google my username... Look around... I've done some fancy things. I'm not a total n00b. So how about it folks? A little help for this guy?
Edited by merlot566jka, Dec 7 2011, 11:43 AM.
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| jeremy_nash | Dec 6 2011, 11:49 PM Post #2 |
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make your engineering student push you everywhere. instant gas savings |
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| Memphis metro | Dec 6 2011, 11:52 PM Post #3 |
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Welcome to the forum. Got any pictures of the vette? |
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| Coche Blanco | Dec 7 2011, 12:01 AM Post #4 |
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Troll Certified
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http://forums.corvetteforum.com/1578892674-post159.html |
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| merlot566jka | Dec 7 2011, 12:03 AM Post #5 |
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Engineer
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Or I am an engineering student... Who is using his phone to write... Love auto correct. I'll post pics of the Vette tomorrow at work. Or look at my photobucket. |
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| Stiffchezze | Dec 7 2011, 12:04 AM Post #6 |
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Sir Metrologist
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Welcome! Sounds like the timing belt is off a couple of teeth. Pull the cover and check to see if the timing marks line up. Just saw where you asked for a pic of the marks. Sorry, I missed that. If you've wrenched before, you can't miss them. I would check them as soon as you can, but don't worry. No matter what you read, a G10 is a NON-interference motor.
Edited by Stiffchezze, Dec 7 2011, 12:15 AM.
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| Shinrin | Dec 7 2011, 01:21 AM Post #7 |
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Ideas to start? My signature |
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| clarkdw | Dec 7 2011, 02:06 AM Post #8 |
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Welcome merlot566jka. When you put the new TB on don't mess with the throttle stop setting. If it still has the plastic cap on, leave it alone. It is only there to prevent the butterfly sticking closed. Has no bearing on butterfly position when running (or shouldn't). That is controlled by the ISC (idle speed controller) The Throttle position sensor setting and the Map sensor will affect the idle. Check vacuum lines. Next step is a compression test compression test Without a cat you will throw a code when the rear o2 sensor reads close to the same as the pre-cat sensor. +1 on checking the cam timing. ![]() |
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| merlot566jka | Dec 7 2011, 11:50 AM Post #9 |
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Engineer
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I had only jacked with the throttle stop to aide the idle. I wouldnt leave it that way for sure. I will adjust the TPS when I re-install the cleaner TB The ISC is in addition to the IAC? I thought I saw two vacuum lines on the back side of the TB for an external IAC?? I am not too worried at the moment about the rear 02. I will make an RC time constant circuit or use an oscillator like the 555 timer to bypass the rear o2. Or maybe mount it further down the line from its stock position for the delay. Either way, a CEL for the rear o2 wont effect the running of the engine. Thanks for the pic, I wasnt sure on this motor, and I didnt want to phase it 180* out. Any other things to look out for to point to the rich condition? I remember seeing something about a coolant passage on the TB?? |
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| Mikemetro | Dec 7 2011, 12:09 PM Post #10 |
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Check vacuum lines. especially the one to MAP. That alone will mess up your idle and run rich. |
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| merlot566jka | Dec 7 2011, 12:24 PM Post #11 |
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Engineer
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Good idea... I figured with out a correct map reading, I would get a CEL... but as you have advised, makes me think if it were just skewed then I wouldnt get the CEL, instead a car that runs like poo with no indication of why. Edited by merlot566jka, Dec 7 2011, 12:39 PM.
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| Johnny Mullet | Dec 7 2011, 12:37 PM Post #12 |
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Fear the Mullet
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Do the compression test please. |
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| merlot566jka | Dec 7 2011, 01:40 PM Post #13 |
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Engineer
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will do tonight |
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| clarkdw | Dec 7 2011, 04:12 PM Post #14 |
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It either has an IAC or ISC, not both. ISC vs IAC |
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| merlot566jka | Dec 8 2011, 01:07 AM Post #15 |
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Engineer
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Compression check: 70 135 135 Wet: 80 155 155 Cyl 1 has a toasted valve. Found a tee line on the map going to some sort of aftermarket cruise control. I've removed it. Still getting a p0134, no signal from o2... Since cyl 1 is dead, I assume that's the issue. Even though ive replaced the o2 sensor. Car idles better. Didn't change the TB yet, going to wait till I do the head. Accidentally welded a hole in the oil filter... Messy! Some interesting welds under that car! No muffler?? After getting the exhaust all welded up, I started it and tons of chunks of carbon crap came flying out... No doubt from the old cat. Still running rich... Really rich. Going to order 3 exhaust valves, head gasket set and some head bolts. Should get it done this weekend or next week. |
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If you've wrenched before, you can't miss them. I would check them as soon as you can, but don't worry. No matter what you read, a G10 is a NON-interference motor.


1:57 PM Jul 11