If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
1988 Oldsmobile 2.5L TBI 192,000 mi, Stalling, Runs Rich?
I am sick of this problem with my car. It has gradually gotten worse
over the past few months. I don't know if all the events are related, but here they are. It started with the cruise control just turning off for no apparent reason going down the highway. That happened a few times over a few weeks (my highway trips are on the weekends). Then, going down the highway, it seemed to shift into the wrong gear, (it's an automatic transmission), and just stay there until it decided to jump back to the "correct" gear, so I thought a transmission problem was developing. After a while whenever it did that, the service engine soon light would come on too, which I could understand, if the idle was wrong and it was in the wrong gear, but now I don't believe it's a tranny problem. Then one day, on the way home from church (30 mph) it started cutting out and when I stopped at the light at the bottom of the hill, it stalled and I couldn't get it started for 5 min or so. I just cranked it to try to start it every 20 sec or so and when it wasn't starting, it just cranked and cranked. But when it finally started, it started immediately, like nothing was wrong. I knew my plugs and wires were overdue, so I decided to change them, hoping that would correct the problem. It didn't, so I replaced the coil for the 1-4 cylinders. That didn't help, either. After searching online and in my Haynes manual and in my notes from college (I have an Associates in Automotive Technology), I started replacing sensors. The current situation is that the car won't start unless I have my foot on the gas (a little). If I take my foot off the gas after it's running, it idles so low, it sounds like it's going to stall. If I go back to the muffler and smell the exhaust, it smells rich (no black smoke though). Sometimes when I try to start it though, it will start and idle normally, but if I leave it running for a while, eventually it suddenly starts to run rough, and really low, and I have noticed at the same time, the fan turns on. Don't know if this is normal or not. OK, so this is what I have replaced/tried, one thing at a time, so I could determine what the cause is. Before this problem started (or about the same time) I had to have my fuel tank replaced (last fall). Then during an indian summer we had this winter, I replaced my fuel filter and fuel lines (with rubber ones). Then once this problem started getting worse, I did the plugs and wires and an oil change, new oil filter, pcv valve, air filter, breather filter. When that didn't work, I replaced the cyl 1-4 coil with a new one because gap on the old plug for cyl 1 was a little wide when I pulled it, and I heard that excessive gap could hurt a coil. That didn't solve my problem. It still cut out randomly and stalled eventually. The cat is relatively new, also. Had a stupid exhaust leak I was struggling with for a while, but eventually sealed. Enough rambling, here's the list. plugs (new, mid-quality) wires (new) coil (new) oil change oil filter (new) air filter & breather filter (new) pcv valve (new) O2 sensor (new) EGR valve (new) ICM (new) MAP sensor (used) ECT sensor (new) Engine temp sensor (in block under thermostat, used) thermostat (new) injector (used) fuel filter (new, but sat around for months before installed) rubber fuel lines (new) TPS (used) crankshaft position sensor (new) I have cleaned the IAC with carb cleaner (I suppose it could just be defective) If I disconnect the EGR valve vacuum line, nothing happens. If I unplug the IAC, nothing happens. If I disconnect the MAP, either electrically or vacuum line, nothing happens. If I unplug the O2S the check engine light will come on, but does not affect idle speed. I have jumped the A & B terminals of the computer connector, and the only code I got was 12, which just means no distributor ref. If I hold my foot on the gas at a low speed, the engine runs so rough it shakes, and if I increase the fuel, the itle speed raises and the shaking is less and I can hear a little miss or something through the exhaust. I can't get it to reset the idle to correct speed by revving it. If an engine is running rich, will the idle go down? or is that contradictory? One website I found suggested replacing the fuel pressure regulator. The last few items I'm thinking of replacing to try to fix this problem before taking it to a shop and paying big bucks for something simple I could have done myself a Fuel pressure regulator (used) -or- fuel pressure regulator diaphragm (new) Engine temp sensor (new) The other coil The TCC solenoid was replaced a couple(?) years ago. The radiator has a very tiny leak, it was replaced used a year or so ago. I replaced the alternator (used) and battery (used) this winter also (because they died). This has now cost me $300 (with the addition of the ICM to the list) and I am now getting very frustrated. At first I didn't mind replacing the sensors since the car has 192,000 miles, they were due. But now it's getting expensive. And if I have to take it to a shop besides... |
Ads |
#2
|
|||
|
|||
> wrote in message oups.com... > I am sick of this problem with my car. It has gradually gotten worse > over the past few months. I don't know if all the events are related, > but here they are. > It seems to me that your neglecting the basics. First, have you checked the manifold vacuum with a vacuum guage? You could have a leak. Another way to check is to use a propane torch and blow propane around suspected leak areas, if you get a change in idle speed you have a leak. And of course there will always be a slight leak around where the throttle linkage connects to the shaft since the shaft has to turn freely. Second have you checked the timing with a timing light? Granted yours is computer-controlled but that just means you cannot adjust it (easily) but it still can be measured. Third have you run the thing through an emissions testing station (most areas of the country have them and quite a lot of states are like Oregon, where emissions testing is free if your not renewing your tags) Fourth have you checked the fuel pressure in the fuel system? Fifth have you disassembled the throttle body and cleaned it? It seems to me that what your doing is guessing at the problem then you replace a part and see if your guess was right. Your not doing any real diagnostics. And frankly that is a shame since your car is an 88 and a GM besides, and you can get real professional grade OTC diagnostic gear that will plug into the diagnostics connector and do that year of vehicle for next to nothing off Ebay, nowadays. Also it seems to me that your favoring guesses that are easy to change out over guesses that take a lot of time and are hard to check out. Like the throttle body cleaning, it takes a while and some effort, compared to changing out a sensor, which you just do in 5 minutes with a wrench and a screwdriver. That is one of the problems DIYers sometimes have, they want to get their car fixed right away, they don't want to spend a long messy time of it, so they favor the easy obvious jobs (like replacing spark plugs) over the hard complex jobs (like reading the factory service manual and following the troubleshooting tree) Ted |
#3
|
|||
|
|||
Ted, well stated, lots of issues just like that on this forum.
"Ted Mittelstaedt" > wrote in message ... > > > wrote in message > oups.com... >> I am sick of this problem with my car. It has gradually gotten worse >> over the past few months. I don't know if all the events are related, >> but here they are. >> > > It seems to me that your neglecting the basics. First, have you checked > the > manifold > vacuum with a vacuum guage? You could have a leak. Another way to check > is > to use > a propane torch and blow propane around suspected leak areas, if you get a > change in > idle speed you have a leak. And of course there will always be a slight > leak around > where the throttle linkage connects to the shaft since the shaft has to > turn > freely. Second > have you checked the timing with a timing light? Granted yours is > computer-controlled but > that just means you cannot adjust it (easily) but it still can be > measured. > Third have you run the thing > through an emissions testing station (most areas of the country have them > and quite a lot > of states are like Oregon, where emissions testing is free if your not > renewing your tags) > Fourth have you checked the fuel pressure in the fuel system? Fifth have > you disassembled > the throttle body and cleaned it? > > It seems to me that what your doing is guessing at the problem then you > replace a part and > see if your guess was right. Your not doing any real diagnostics. And > frankly that is a shame > since your car is an 88 and a GM besides, and you can get real > professional > grade OTC diagnostic > gear that will plug into the diagnostics connector and do that year of > vehicle for next to nothing off Ebay, > nowadays. > > Also it seems to me that your favoring guesses that are easy to change out > over guesses that take > a lot of time and are hard to check out. Like the throttle body cleaning, > it takes a while and > some effort, compared to changing out a sensor, which you just do in 5 > minutes with a wrench > and a screwdriver. That is one of the problems DIYers sometimes have, > they > want to get their > car fixed right away, they don't want to spend a long messy time of it, so > they favor the easy > obvious jobs (like replacing spark plugs) over the hard complex jobs (like > reading the factory service > manual and following the troubleshooting tree) > > Ted > > > ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#4
|
|||
|
|||
well, i don't have gauges to check vacuum and fuel pressure, so i
didn't do that. this morning, i started it and it ran fine. i took some starter fluid that someone gave me to find out if i had a vacuum leak and sprayed it around and it didn't affect the idle. i decided to take it to a shop right by my house. my boss is asking a favor of the guy to check out my car. he's going to look at it tomorrow to confirm, but when he asked me what the car was doing, plus a couple leading questions, he immediately said they were indicators of the main computer going out. which is what i originally thought, myself, since my mom's car did this (similar symptoms) a couple years ago. but i was mistaken in what the icm was. i thought that was what i was replacing was the computer. silly me. the mechanic at this shop said it's behind the right kickpanel. now i just feel like an idiot. |
#5
|
|||
|
|||
> wrote in message ups.com... > well, i don't have gauges to check vacuum and fuel pressure, so i > didn't do that. this morning, i started it and it ran fine. i took some > starter fluid that someone gave me to find out if i had a vacuum leak > and sprayed it around and it didn't affect the idle. > i decided to take it to a shop right by my house. my boss is asking a > favor of the guy to check out my car. he's going to look at it tomorrow > to confirm, but when he asked me what the car was doing, plus a couple > leading questions, he immediately said they were indicators of the main > computer going out. which is what i originally thought, myself, since > my mom's car did this (similar symptoms) a couple years ago. but i was > mistaken in what the icm was. i thought that was what i was replacing > was the computer. silly me. the mechanic at this shop said it's behind > the right kickpanel. now i just feel like an idiot. > I will bet you a short case that the main computer is not going out in this car. And I said propane, not starter fluid. If there is a vacuum leak in a hose somewhere that you spray with starter fluid only some of the fluid will get sucked in and it will certainly wick to the side of the hose long before it makes it to the manifold. Not to mention spraying starter fluid on a running engine is a taking a chance you are going to catch the car on fire. Mechanics always blame the computer when they perceive that they are talking to someone who isn't car savvy. The reason is that if your shaky on your vehicle mechanical knowledge, you almost certainly look at the computer as a big black box and are quite willing to believe that something is wrong with it. Ted |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
1988 Jeep Commanche keeps stalling | smuirhead | 4x4 | 1 | May 18th 05 01:58 PM |
1988 Suburban TBI stalling and choking | tpcolson | 4x4 | 1 | December 5th 04 07:19 PM |