z34_nut Posted May 6, 2005 Report Share Posted May 6, 2005 This will prolly be a long post, so hold on tight. Monday: Started out like every-other day. warmed the car up in the morning, got dressed, brushed my teeth, got my lunch togeatehr and headed out the door. Drove to work just fine. Afternoon: I head back home for lunch, and drives fine on the way there, and on the way back. Afterwork: Immediatly as I start it up, the car sounds like shit, and has an idel jumping around by a total of 200 RPM. I Drive the car home, and it has a total loss of power. My initial thought was a dead cylinder... Get home: I Got home, all I smell is gas, bad. The fucking thing smelled like a damn lawnmower when you first start it up. Well from there I go about with my personal diagnosis. That is after I come in and eat some food and so on. Get back outside, open the hood, I first check vaccum lines. The Intake vaccum was not connected with the plenum. Immediatly I plug that vaccum in and start the car (BTW I checked all fluids blah blah blah). I also checked timing belt, that was fine. It runs good. So I figured ok, problem solved. Tuesday: On my way to work, the car seems to run fine, untill about halfway there. It was like a switch had gone off in the car. The thing runs shitty, 50% power at most.. I get to work, late and pissed. Work all day, don't go home for lunch. At 3:30 I poped the hood in the parking lot at work. I look all over for faulty vaccum lines, or perhaps another one split open by the exhaust stem to the EGR valve again (this is what happened to my cruise control.) I look in the back of the MAP sensor. It is totally unplugged, 0 vaccum. Great i thought. I plugged it back in, started the car. It ran good. I figured, ok, so now I got it down, it runs good now.. Weds: I drive the car all day, no problems. Today: Car runs like shit in the AM again... Checked all lines again with the vaccum. They look good. Crap. Didn't drive the car again at lunch. I was going up to my g/f's place after work, and it drove all the up there fine. We used her car for the night, and then when it came time to leave I started the car up, and it was still running good. I go back inside to say goodnight, And when I come back out, the car apperently switched over to "I'm gonna run super rich for w/e reason I feel like". On the way home, the car suddenly snapped out of it going up a hill, kinda threw me back in my seat, took me by total surprise. When I got home, I hooked up an inductive timing light to make sure all wires were firing. Indeed they were... I have no SES lights, or any withstanding codes. I have checked the codes several times in the past, and I have no gotten a light since. I suspect I have no stored codes. This is on the 1993 z34, completely stock except for K&N drop in, and FFP chip. What would cause the PCM to make the car run uber rich at what seems like totally random situations? I suspect the EGR, and the FFP chip. The stock chip is going in tommorrow at lunch. I hope this fixed the problem. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted May 6, 2005 Report Share Posted May 6, 2005 Could be alot of things, I bet it's the PCM, Coil, or a fuel delivery problem. Quote Link to comment Share on other sites More sharing options...
z34_nut Posted May 6, 2005 Author Report Share Posted May 6, 2005 I thought about coil, but there shouldn't be an "in the middle" position. All plugs are firing fine according to my inductive timing light.. Because of the disconnected MAP sensor, would the car need an idle re-learn? I'm going to try this during break (which is right now). lunch time is coming up, I'm hoping switching the stock chip in would work if the re-learn doesn't Quote Link to comment Share on other sites More sharing options...
Canada Posted May 6, 2005 Report Share Posted May 6, 2005 Does it flash code 12? So we know the PCM is working properly. No other codes? You've had troubles with your vacuum lines......I'd look at those....either by sealing them somehow or replacing them. Quote Link to comment Share on other sites More sharing options...
Crimson Fury Z Posted May 6, 2005 Report Share Posted May 6, 2005 it putter going from a stop, or low rpms? thats what happened to me when one of the coils went sour. icm? that crap is serious, sputtering popping no acceleration, and its intermittent/then progresses south. Quote Link to comment Share on other sites More sharing options...
JoroCorona Posted May 6, 2005 Report Share Posted May 6, 2005 I wanna know how your blowing all your vacuum hoses off. It sounds like its backfiring into the intake and blowing your vacuum hoses off. I'd check your injectors, sounds like one of the is grounded and constantly open, causing uber rich and the possibility of a backfire into the intake. Quote Link to comment Share on other sites More sharing options...
Canada Posted May 6, 2005 Report Share Posted May 6, 2005 I think its the fact that the vacuum lines are old.....the lines pull out of the connectors, it happens. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 6, 2005 Report Share Posted May 6, 2005 I wanna know how your blowing all your vacuum hoses off. It sounds like its backfiring into the intake and blowing your vacuum hoses off. I'd check your injectors, sounds like one of the is grounded and constantly open, causing uber rich and the possibility of a backfire into the intake. I was thinking backfire myself. Two seperate incidents of blowing vac hoses off? Get a vacuum gauge, a long vac tube, and a T connector and throw it on there in the morning before you start driving, and see if it spikes. Should be around 17-21" at idle and 0 at WOT. Quote Link to comment Share on other sites More sharing options...
LukeZ34 Posted May 7, 2005 Report Share Posted May 7, 2005 May not be your problem, but when I had my Lumina, I had an injector that was actually leaking gas. It had a hairline crack in it and it would pool the fuel under the plastic 'Twin Dual Cam V6' cover. The car would reek of raw fuel, and I noticed some drivability problems soon after I noticed the problems. Ypu may not have that same problem, but it sounds like an injector issue, or something with the fuel system. I'd be checking your fuel pressure and then check your injectors w/ a multimeter and make sure they read the correct resistance (ohms). If you haven't ever replaced the fuel filter this would be the time to do it. I'd also look at replacing some of your problem vacuum lines just for good measure. Quote Link to comment Share on other sites More sharing options...
z34_nut Posted May 7, 2005 Author Report Share Posted May 7, 2005 Ok, many vaccum lines are new, I tested my injectors with an occilloscope (SP?) and they show normal deviations. This how-ever was about 3 months ago. I also checked the coils in the same time frame (I checked every system in the vehical for my non-stop 1,000+ mile trip.) This was all about 3 months ago. I have no codes. I did an idle re-learn today with the FFP chip in the car. Didn't do a damn thing. I took the FFP chip out, put the stock chip in, ran good after idle re-learn, drove it about 30-40 miles, ran fine. Parked the car for 30-45 mintues. Started it up and it ran like shit again. Driving home, it (the car) was confused. When I first started it, the car ran good. It seems as soon as I hit the 3,000RPM mark, the car runs shitty again. If I didn't accelerate, the car would come out of it, and run fine again. This happened about 3 times in and out during a 25 mile period. This never happened with the FFP chip, it either ran great, or didn't run worth a shit. I will not be driving the car again untill this issue is resolved. If there was a problem with the fuel system, would it run rich? My assumption it would run lean if anything? I set up an appointment with an ASE master/GM tech (friend of mine) to help me with this. The car goes into his hands May 17th...I'm sending it to him because of his greater knowlege, and my lack of equipment to properly acess this situation.. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 7, 2005 Report Share Posted May 7, 2005 Fuel filter, or I'd seriously say coils. Maybe get another known good ICM and coilpack set and just switch them out. Quote Link to comment Share on other sites More sharing options...
89GPSE Posted May 7, 2005 Report Share Posted May 7, 2005 I would say a coil pack is going bad. Quote Link to comment Share on other sites More sharing options...
z34_nut Posted May 7, 2005 Author Report Share Posted May 7, 2005 Fuel filter, or I'd seriously say coils. Maybe get another known good ICM and coilpack set and just switch them out. I'd like to say that too, but my biggest concern is that it could be SO many things. Having the right tools and diagnosis help keep the cost of repairs down. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted May 7, 2005 Report Share Posted May 7, 2005 Fuel filter, or I'd seriously say coils. Maybe get another known good ICM and coilpack set and just switch them out. I'd like to say that too, but my biggest concern is that it could be SO many things. Having the right tools and diagnosis help keep the cost of repairs down. That's why I suggested the vacuum gauge up above. Quote Link to comment Share on other sites More sharing options...
z34_nut Posted May 7, 2005 Author Report Share Posted May 7, 2005 Fuel filter, or I'd seriously say coils. Maybe get another known good ICM and coilpack set and just switch them out. I'd like to say that too, but my biggest concern is that it could be SO many things. Having the right tools and diagnosis help keep the cost of repairs down. That's why I suggested the vacuum gauge up above. Lack of tools really sucks. I can't think of any-one to borrow one from. Quote Link to comment Share on other sites More sharing options...
JoroCorona Posted May 7, 2005 Report Share Posted May 7, 2005 You can rent a vacuum guage from autozone... or shit, they aren't very exspensive` Quote Link to comment Share on other sites More sharing options...
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