I replaced the O2 sensor tonight and when I started the car it surged way up and way down .... .. . . . . . . but didn't stall this time. SO I tried to do the idle relearn procedure but the fan never kicked on after like 15 minutes I got impatient and took her for a spin. The car was sluggish and the throttle response isn't what it should be but..... no pop or backfiring and no stalling. I tightened up the MAP sensor connector with zip ties which was still a little loose and will try again tomorrow. It looks like the O2 sensor might have been the culprit or at least contributed to the problem. It is definitley running better, but I won't know till I start it up at 8am. Wish me luck, apparently I got a little tonight.
IP: Logged
08:30 PM
Bigfieroman Member
Posts: 2416 From: Pleasant Hills, PA, near Pittsburgh Registered: Nov 2000
I am thinking this may be my issue to...I have a new one and it will be put in early next week. Mine looks original. Come one Connecticut, hurry up and fix our damn cars! j/k
I know this is getting ridiculous. I have swapped a 2.5 for a used 2.8 in my car and then replaced that with a reman 2.8 yet I can't even get the thing to stay running.
My O2 sensor was replaced two years ago, but since then I drove the car with a shattered piston ring and probably ruined the O2 sensor from all the oil and crud in the exhaust, but it looked clean when i removed it earlier.
Question: Are you supposed to screw the O2 sensor all the way to the end of he thread? It didn't want to go past about 3/4's.
When you replaced the MAP sensor, did you replace it with one of the same connector color? If you look inside where the connector plugs in, you will see a colored insert. I think mine is Green, but I have seen Red and Black ones. I remember reading that this made a difference in what they read or how they worked.
IP: Logged
11:04 AM
aaronrus Member
Posts: 870 From: bradenton, FL USA Registered: Nov 2003
It is a possibility, and yes it has been mentioned. But I did replace that sensor about a year ago. Also the car starts fine but then won't stay running at idle. SO I know the injector is firing and that means the cold start injector switch is sending a signal. The possibility of it severely leaking would cause a rich mix and stalling out, but I am putting my money on the EGR right now. I have a spare cold start injector to test with if need be after tomorrow though.
dude... you dont need to put any money on the EGR valve bro.. just plug the vacuum line going to the EGR, and use 89 octane gas, you'll be fine. The EGR robs you of performance to begin with. again, CHECK YOUR FUEL PRESSURE at idle and WOT.. stop replacing parts at random like a jackass.. test for the problems first. it starts up, so you know you have spark. you dont have any vacuum leaks, so test your fuel pressure next bro.. c'mon.. quit bouncing all over the place.. this thread should have been no more than two pages long.
IP: Logged
11:37 AM
aaronrus Member
Posts: 870 From: bradenton, FL USA Registered: Nov 2003
I know this is getting ridiculous. I have swapped a 2.5 for a used 2.8 in my car and then replaced that with a reman 2.8 yet I can't even get the thing to stay running.
My O2 sensor was replaced two years ago, but since then I drove the car with a shattered piston ring and probably ruined the O2 sensor from all the oil and crud in the exhaust, but it looked clean when i removed it earlier.
Question: Are you supposed to screw the O2 sensor all the way to the end of he thread? It didn't want to go past about 3/4's.
OMG.. dude.. screw it all the way down till it is hand tight with the o2 sensor tool.. check your bloody fuel pressure at idle and WOT!!! you are bouncing all over the place.. use cohessive steps when you troubleshoot, not random guesses!
dude... you dont need to put any money on the EGR valve bro.. just plug the vacuum line going to the EGR, and use 89 octane gas, you'll be fine. The EGR robs you of performance to begin with. again, CHECK YOUR FUEL PRESSURE at idle and WOT.. stop replacing parts at random like a jackass.. test for the problems first. it starts up, so you know you have spark. you dont have any vacuum leaks, so test your fuel pressure next bro.. c'mon.. quit bouncing all over the place.. this thread should have been no more than two pages long.
I certainly don't mind your input but you don't need to be abrasive. I need my EGR because we have emissions inspections here in CT, I can't just block it off. Secondly I am not replacing parts like a jackass, and this thread is longer than 2 pages not because I am too stupid to find the problem, but because the problem is that all the sensors are reading pretty much right according to winALDL, and I replaced every sensor, switch, ignition component, and the engine itself within the last two years. So that leaves no obvious culprits causing the problem. I did check the EGR vacuum line a while back and it made no difference to the idle, but then after exhausting other avenues I tried again and got my car to stay running for more than 5 seconds. So what is wrong with thinking it was possible that the EGR was stuck open?
I would love to be able to just check my fuel pressure, but I don't have a gauge and i don't have money to burn. I was really hoping it was my EGR causing the problem and I picked up a new unit for $25, I wish I hadn't now that I see it didn't help, but the EGR I had on there was sticking a bit when I tested it off the car so I guess its probably a good thing that I replaced it anyways.
The O2 sensor actually helped, adn the reason for replacing that as my next option is that I got a code 44 lean exhaust. If my car smells rich and the BLM are pegged, then I guess that its probably the O2 sensor. My last engine had a shattered piston ring and was blowing black soot through the exhaust and I was using that same O2 sensor so again its not difficult to believe that even a 2 year old O2 sensor might be bad. Heck even the Helms manual says replace the O2 sensor as one option for a code 44.
ALl the other parts I swapped on and off were only because I have boxes of them in my house, I know they work so if I swap one in and the problem goes away, then I know what is causing the problem. It seems perfectly logical to me to swap an IAC, TPS, MAP, MAT, and EGR solenoid if I have good working units to troubleshoot with. I also ran winALDL and couldn't really find anything solid to tell me what the problem is.
So now I have a running car, yet it surges. Before I had a non running car that stalled every time it idled. I am making progress. You are right i need to check the fuel pressure, but until I get a gauge I can't do that. Last night I only had time to do one thing, I chose the O2 sensor, and apparently that worked out because I drove my Fiero to work today.
[This message has been edited by connecticutFIERO (edited 09-24-2004).]
OMG.. dude.. screw it all the way down till it is hand tight with the o2 sensor tool.. check your bloody fuel pressure at idle and WOT!!! you are bouncing all over the place.. use cohessive steps when you troubleshoot, not random guesses!
You need to seriously chill out. Did you read what I wrote. It wouldn't thread past 3/4's. It is sealed, its not cross threaded. I was just wondering if its necessary to force it the rest of the way because there is a washer that sits at the base or if just sealing its fine and dandy. I didn't want to tighten so much that I won;t be able to remove it next time. ANd by the way I used a wrench not an O2 sensor tool. You have no idea what a pain in the ass its been trying to track this problem down. If this was a fuel pump problem the idle wouldn't have gotten better when I replaced the O2 sensor.You seem to have this picture in your head of me running around like a chicken with my head cut off randomly replacing parts. I know my way around an engine, I installed this current 2.8 almost completely alone. And I managed to do it after work at 9pm in about a week. (thanks for helping me drop the cradle Jnco)
[This message has been edited by connecticutFIERO (edited 09-24-2004).]
IP: Logged
12:00 PM
Wesley Member
Posts: 768 From: New Orleans, LA Registered: May 2004
You need to seriously chill out. Did you read what I wrote. It wouldn't thread past 3/4's. It is sealed, its not cross threaded. I was just wondering if its necessary to force it the rest of the way because there is a washer that sits at the base or if just sealing its fine and dandy. I didn't want to tighten so much that I won;t be able to remove it next time. ANd by the way I used a wrench not an O2 sensor tool. You have no idea what a pain in the ass its been trying to track this problem down. If this was a fuel pump problem the idle wouldn't have gotten better when I replaced the O2 sensor.You seem to have this picture in your head of me running around like a chicken with my head cut off randomly replacing parts. I know my way around an engine, I installed this current 2.8 almost completely alone. And I managed to do it after work at 9pm in about a week. (thanks for helping me drop the cradle Jnco)
i apologize for my abrasiveness.
if you cant afford a fuel pressure tester, borrow one. just from a random guess, the way yoru car was acting before, with no vacuum leaks, i would have guessed lack of fuel pressure and/or bad o2 sensor. it seems yrou o2 was definately bad. as soon as you test yrou pressure, post the numbers for idle pressure and wot pressure here on the group.. and we'll take it from there
if you cant afford a fuel pressure tester, borrow one. just from a random guess, the way yoru car was acting before, with no vacuum leaks, i would have guessed lack of fuel pressure and/or bad o2 sensor. it seems yrou o2 was definately bad. as soon as you test yrou pressure, post the numbers for idle pressure and wot pressure here on the group.. and we'll take it from there
I'll pick one up when I get extra cash. I need a FP gauge anyways, to set my fuel pressure safety switch at the right PSI for my nitrous. At this point I am happy to have a running car again.
Check with some of your local parts places. Several of them have loaner tool programs where you just have to put down a deposit that you'll get back when the tool is returned.
------------------ RickN White 88GT 5spd White 85GT Auto
IP: Logged
11:36 PM
Sep 26th, 2004
aaronrus Member
Posts: 870 From: bradenton, FL USA Registered: Nov 2003
I'll pick one up when I get extra cash. I need a FP gauge anyways, to set my fuel pressure safety switch at the right PSI for my nitrous. At this point I am happy to have a running car again.
Autozone loans out a FP gauge. you leave a desposit with them and they refund it when you bring back the tool
IP: Logged
05:48 AM
Oct 1st, 2004
Bigfieroman Member
Posts: 2416 From: Pleasant Hills, PA, near Pittsburgh Registered: Nov 2000
Brand new Bosch O2 sensor, new, very high quality brass insert cap and rotor set, new NGK UR5 plugs, properly gapped, and new STI wires made NO difference in mine.
IP: Logged
12:13 AM
Austin Member
Posts: 264 From: Central Indiana Registered: Sep 2001
Just a thought but have you checked you EGR tube? It goes from the upper intake to the EGR valve. Often they will crack/break and cause idling problems. They can be a little harder to check if the heat shield is surrounding the tube.
I apoligize in advance if this was mentioned earlier in the thread.
IP: Logged
12:19 PM
alienfiero Member
Posts: 638 From: auburn, wa., usa Registered: Aug 2004
Originally posted by connecticutFIERO: You are probably right, thats also probably one of the reasons they are prone to cracking at the welds.
Make sure that your engine mounts, especially the dogbone are in good condition. I would even suggest using polly on the dogbone instead of rubber if you haven't already. Engine movement will put extra strain on those manifolds.
------------------ RickN White 88GT 5spd White 85GT Auto
Last weekend I put and additional ground strap on the engine. I bought a ground strap from NAPA, 1" wide by 11" long, and attached it between the bolts on each end of the dogbone, it ain't pretty but it works well. I drove the car to work all week, this has not eliminated my hesitation (my car did not die, just stumble) at cold startup but the engine now recovers much quicker and settles into a strong constant idle immediately after. As I said in another thread, even the power windows run up and down faster now. I'm going to take some of the suggestions here and look in the throttlebody area next.
------------------ RickN White 88GT 5spd White 85GT Auto
IP: Logged
04:28 PM
Oct 3rd, 2004
Bigfieroman Member
Posts: 2416 From: Pleasant Hills, PA, near Pittsburgh Registered: Nov 2000
Newsflash!! Apparently I never let the computer learn to idle correctly, and that is why I was still having the problem. I was showing a friend how the engine idles rock solid after warming up and let it idle for 30 minutes while we talked. The next morning, I started it, (50° out, expected it to stall 3-4 times) and it started right up and idled perfectly!!! YAY!!!! It was the O2, I think, but it could have been the cap and rotor, the wires, the mis-gapped plugs, or the dirty IAC, because I did it all at the same time. I am so happy!!!!!
Thanks Aus! 
