I have a problem that is driving me nuts. I'm trying to get my 54 together to take to the hangin dice show in august but just recently all my vehicles have laid down on me. My wifes daily driver is the one thats driving me nuts. Untill I get it fixed I can't get back to work on my 54 which desperatley needs work. Her car is a 96 camaro RS with the 3.8 v6 engine and the car has a weird miss. It doesn't miss all the time but it does miss alot. I had O'reily's use the scanner on my car and I had 3 codes in it one of which I know what is. There is one that stays in the computer and it is P0420 catalyst system. Its because someone cut the cat off of the exhaust but it hasn't been a real problem other than the engine light staying on. Its the next two codes that are getting to me. P0305 cylinder 5 misfire detected And P1200 fuel injector Injector circuit fault. I've changed the plugs in the car, the plug wire, the coil pack. It has done nothing. The car does it alot when you shift to reverse damn near everytime you shift to reverse infact. It does it while Idling and low speeds but seems to run alright when going down the road. The exhaust smells like it is loading up bad. Lots of raw gas smell coming out of the tailpipe when its missing. I thought about changing the injector but I don't think that is the problem either. It just started doing this all of a sudden we have been driving the piss out of this car lately and it has done fine, But now I want to smash the car with a big sledge hammer. I also had the control module checked and it checked out fine. Does anyone have any suggestions or help I'm desperate I hate working on our latemodel shit I reeeeeeeeeaaaaaaalllllyyyyy want to work on my 54 but I can't untill I get this piece of shit running right. When I get that fixed I also have to change the wheel bearings in my suburban then I can work on my baby again. I hate fuel injected pieces of shit but we need the gas mileage right now. I would let a shop work on it for me but I'm broke as hell. So I would really appreciate any help PLEAZZZZZZZZZEEEEEEEE...... Does anyone on here have one of these cars maybe with the same missing problems???
In my own expierience's with OBDII car's, i've run across a LOT of #? cylinder misfire's. Sometime's they say which cylinder, like your's, and other time's it just tell's you "random misfire detected. What i think is happening is, the "misfire" code has been set because the computer is picking up the skip, and the "Injector circuit fault." code is telling you why it's skipping, in a vague way. In *most* cases, plug wire's and plugs solve the problem..next in line were the coil packs, or pack. However, i have run into some that have a misfire code and it's one of the injectors themselve's or the wiring going to them, although the wiring is not common. Depending on how many mile's the car has, there's a possibility the #5 injector is not working all the time. It could have shit in the pintle valve, or just week in general. I have no axcess to my work info here, but what you need to do is find out what the troubleshooting tip's are for the "Injector circuit fault." code and start there. It may be as simple as one week injector like i said. If i get a chance at work tomorrow i'll see if i can dig anything up for you and let you know.
Another very good point! Check the intake to see if there's any vacuume port's off the #5 cylinder runner. If there is, check to see if the fitting is cracked, or have cracked hoses going to them...
My ex girlfriends car did something similar. I went through everything. Finally found out it was just a sensor problem. Pcv or idle control. Not sure. A friend ended up taking car of it...I had to go back to school. Seems like the biggest problems on computer controlled cars have the simplest solutions. It just takes time to track down the "real" problem. b
I changed #3 plug wire three times in 20,000 miles on a 4.3L V6 with those symptoms, They kept melting/burning. Third wire lasted 130,000 miles. Open the hood on a really dark street and see where the sparks are flying when it misses.
-------------------------------------------------------------------------- Man, there is a lot of possibilities with all the sensors and vacume lines and injectors, etc. One i had problems with, symptoms simular to yours, turned out to be a bad fuel pressure regulator on the fuel log. It was leaking gas internally, and went into the intake, via a vacume line, that let the leaking gas go directly into the intake and cause the engine to run like crap at low speed or idle. That set off false readings from the sensors to the 'puter' with all kinds of false codes. Hope you find it and please let us know when youu do. Good Luck to ya.
At my old shop there was a car repair place next door. They had a car with a ramdom missfire that drove them nuts for about two weeks. They changed and/or checked everything. Finally found a broken ground wire in the TRUNK. Seems what ever the wire was suppose to ground was feeding back through the computer. Fixed the ground wire, car ran great. Check all the cars ground wires. Gene
Tips for fixing a newer car: 1. Drive to bad neighborhood. 2. Yank ignition with dent puller. 3. Spray interior with carb cleaner. 4. Throw lit road flare through window. 5. Dance around the burning pile of crap like a wild Indian. 6. Report car stolen. 7. Collect insurance money. 8. Buy a pre '70 American made vehicle.
Don, make sure you don't have a plug wire crossed. I mean, really check it. This same thing happened to me a couple of weeks ago on a Chevy P/U. It was running bad when I tuned it up, and it seemed to get worse and worse. I put all sorts of new tune up oriented items on it and still acted the same. It was darn near pouring fuel out of the exhaust as well. It showed up "misfire" and running too rich on Bank 2. Finally after throwing parts at it, I took it in town to to have it fixed. They had it fixed in less than 30 minutes. Although, I do know for a fact. Gutted catalytic converters on most 6 cyl camaros, NEVER RUN RIGHT!!! If you have O2 sensors after the cats, you're gonna HAVE TO put cats back on in order for it to run correctly. Good luck, I hope it's a simple fix. Reverend Jake
I know the cataylitic converter is a problem that I'm going to try and get fixed soon. I'm going to check the crankshaft sensor today after work since it is the sensor that tells the module when to fire and on what cylinders to fire. If that doesn't turn up anything I'll check into the stuff that controlls the injectors and check the injectors. Maybe I'll turn up something. I'll also check for vaccum leaks to.
The CAT will not cause any problems with how the car runs...the CAT and rear O2 are there for emissions only so don't even worry about that. Here is what I would do. Since the computer gave you a specific injector swap it out with #6 then reset the computer (I can tell you how to do that as well). Drive the car until the SES light comes back on and see if the problem moved to #6 or stayed with #5. If it moved then you know it is the injector but if it stayed with #5 then something is wrong with the wiring for that injector. To reset the computer: Turn the ignition on but do not start. Remove the PCM IGN fuse and the PCM BAT fuse. Turn the ignition off and wait 15 minutes. Replace fuses and that should do it. Hope this helps.
I checked my Alldata today at work and printed up a 'flow' chart for the P1200 code. basically, it give's a diagnostic road to travel to find the reason that code was set. It also said that with P1200, you will also have another P300 misfire code set as well due to whatever is causing the P1200. The only problem i have is it's 5 pages long and i don't have a scanner to get in on here. I'll see if i can get it scanned and e-mail it to you.
Those things don't have a regular distributer, just that 3 pack lookin' thing on the front of the motor, check that. Fuckin' better than goddamn Opti-spark piece of shit on LT1's. Some GM wizard put the thing under the waterpump so when antifreeze leaks out it kills your distributor. If you are on here, LT1 Designer, you sir need your ass kicked. Whew! I feel better...
The readings from the o2 sensors play a major part in the way the computer monitors and regulates the air/fuel ratio,so yes they can make a difference in the way the car runs. In Dons case probably defaulting to a lean condition since there is no reading from the rear at all. I agree on swapping the injectors, it may be a little work but it'll answer that question.
Only the upstream (pre-cat) O2 sensors are used for L-Trims and S-Trims (Long and short term fuel trims..short are real time adjustments and long are stored values the computer develops and uses to maintain best performance/economy) as well as some timing adjustments. The down stream O2 sensors are used for cat performance feedback only...when the computer senses a value outside the set parameter it will set the 'SES' light and store a code. This way unsuspecting car owners will go to the repair shop or dealer and pay 300 bucks for a new cat. Where as people like me will just remove the cat and delete the codes related to emissions (Yes I use a laptob and software to tune my car...I am sorry but it is the price I have to pay to race late model LS1's). However there may be other conditions present that will cause the computer to think the cat is not working properly and create performance problems...like and exhaust leak or a dead cylinder that pushes raw fuel out or a dead injector that pushes more air out. My educated guess for his problem is a bad injector. For the cat problem I don't know for sure because it could be several things...all I do know is that a bad cat will NOT effect performance of the vehicle on OBD II systems (unless it is clogged then duh no exhaust flow). OBD III is a new ball of wax all together...lets just say big brother will know when you fart in your vehicle and the feds will show up if you ever pop the hood!
You are correct my friend. I guess I was under the impression that all the o2s' were missing under his car, I don't know where I was at. I'm also gonna go with the injector on this one. Swap it and see if the promblem follows it, also check the connectors real well, I've seen some wierd bent pins and chaffed wires in connectors before usually caused if the car has ever had any service work performed on it before. (careless techs prying stuck connectors off with screwdrivers and crap)
The injector is my next step after I try and check the crank shaft sensor. I've had crank shaft sensor screw up and cause gm cars to act stupid like this. When I did a search on yahoo for this problem I found a forum where there were several people on there that had my same problems with they're camaro/firebirds. My car just has the cat gone all the O2 sensors are still there. The car has ran fine since we got it with out the cat on it and we've put alot of miles on it. Then one day it just starts crapping out. I've checked and or replaced damn near everything in the ignition system so far other than checking sensors.
The Jalopy Journal
