95 4cyl 142K shakes real bad on start up

[joe45]

I know my plugs are good and the wires are OK. On start up it hardly starts and when it does it sounds like its running on two cylinders. It shakes real bad but when you start driving it runs fine. I don't know if it has a vacuum advance timing or not. I haven't found any vacuum leaks.
It must be something with the ignition because it smells like gas. This car is on its last leg, its on its 2nd head so I would like to get a little more life out of it.

[jsgold]

Might have a coil going bad. There are two on yours and they each handle 2 cyl. Possible for a bad one to fire one, so you could have 1 weak/dead cylinder or two. Of course could be other things if you smell gas, but have any trouble codes set on your computer? Your car has no timing control other than the computer itself. Uses crank sensor and igntion module and coils to keep timing right. If a crank sensor goes bad or igniton module goes bad you have no fire. If there are no trouble codes stored I would kook at the coils. They sit on top of your ignition module. Have to remove as whole assy. Then you can take apart and test, or have tested. First though buy yourself a small cheap tester for firing,(looks like a spark plug) and test all 4 cyl for fire. Buy them at Advance or Auto Zone. Might want to get a Haynes manual too, to help you out with other tests. 142K is not the end of the line on your car, should go another 40-60K if it has been taken care of. But these things will go bad along the way. D/C the plugs and wires anyway, just in case. Be sure your inytake area is clean, IAC control cleaned of carbon, and check all vaccum lines, especially to your MAP sensor. If you find a cylinder not firing, remove the coils and module, test and replace any bad. many people replace the entire assy, but can run 100-120 bucks to do so. If you have trouble codes there is a place to start. MAP sensor, EGR valve, even your Oxygen sensor can cause a misfire. These SHOULD trigger a code when bad.

[joe45]

Thanks, it does have a code because the light is on. My friend has a computer I just have to get the car over there. Thanks for your help!

[joe45]

More problems nows its missing all the time. When going up an onramp to the highway it lounges and shakes as the motor cuts out trying to get up to speed. The service engine light only comes on when the cruse is on. Once the cruse is set it only misses when you are going up a hill or load the motor. If this is the coils how hard are they to remove? What tools do I need? Thanks

[jsgold]

Really should do a couple of tests before removing the coils. Should try to get ANY trouble codes on the car first, and then get a tester to check firing on the wires. If money is not a major problem I would go to Advance and get (1) ODBI tester for $20-25 bucks, and (2) a Haynes manual as it can help greatly here on this problem, and (3) a cheapo firing tester. The code(s) give youa starting place to look, and all you may find is a mis fire code. However you may find you have a bad MAP sensor (failrly cheap and easy to fix), or a bad EGR (not so cheap). Having said that you must find the coil packs, which I think are on the back side (unfortunaltey) of your motor. Trace your plug wires and you will find it easily. You have to remove the plug wires at the coil packs, marking them as to where they go, remove the wires (should be 2-3 sets of wires pluging into the DIS assy, which is the ignition module(sits under your coil packs, it is flat) and then you remove three bolts in the DIS (do NOT remove any bolts from the coils them selves, that will make your job harder). When you remove the three bolts the entire assy should pull out, module and coils. You can then remove the 4 screws and take the coils off. I would recommend replacing both rather than one, but do the testing and you might be able to replace one if you can find the bad one. Take the module to Advance and get it tested for free. Not impossible that is bad or weak. If bad, replace all three. My opinion, but, while this stuff is out you can remove the crank sensor, sits under the module and plugs into your engine block. These are not very expensive and might save you a lot of trouble down the road. usually the first thing to fail on a Corsica. Your choice. Bur get the manual, tester, and firing tester. You may have a time of it as you may have limited room. But certainly do-able. Costs are usually around 80 bucks for a DIS module, 20-25 bucks each on a coil, crank sensors can range from 15-50 bucks. Install the coils back into the DIS and replace the 3 bolts and see what happens. Do not throw money at it though without some testing. Would recomend a total tune up and vacuum line check while you are working on it. Clean the IAC in case it is diirty and replace filters(fuel and air).

[joe45]

Thanks your a corisca GOD!!!

[jsgold]

Nah, just have owned a 91 since new and my son has owned two Berettas. Have had a lot done to them over the years sometimes by me, some by others if not something I had the tools for or the time. Hope this helps you out. These old cars will easily get 200K on them with a little TLC and their parts are CHEAP compared to other cars.

[joe45]

I replaced the coil on 2 and 3 but it still has codes 32,33 which my book says is the map sensor and the egr valve. Where is the map senor and should I replace it?

[jsgold]

If the car is running better i would not rush out and buy parts yet. A badly running engine can cause codes to set simply because the conditions exist for the codes to set, not always due to the sensor(s) being bad. "If" it is running better I would clear the codes by unhooking battery or having it done if you have OBDII(Advance or wherever you bought your parts) and run it a while and see if any others set. One sensor can cause another to set too. If it is still running poor, or, not what you had before the MAP sensor would be the one to replace first,as it is the cheapest, easiest, and more likely of the two. But, check the vacuum lines, especially to the MAP sensor just in case. Ours had rotten lines and after replacing them ran fine. The MAP sensor is a square sensor, easily visable. Here are pics of map sensor. Should be easy to spot on your motor. Again, if it running better, clear the codes, run it for a week or so, and check for codes again.

http://www.robietherobot.com/storm/mapsensor.htm
http://www.partsamerica.com/ProductD...pe=414&ptset=A

[joe45]

I should of cleared the codes like you said. Its hitting on all 4 right now but it wont idle very well and it dies when you come to a stop.

[jsgold]

Well that would go along with the codes you have, but, there are other things that can cause stalling. The TCC can cause stalling but, does not sound like that's it. It causes the car to stall when it gets hot, will restart OK but stalls as soon as put into gear. very common. But, since you say it does not idle well, sounds like a vacuum leak, dirty IAC control, MAP sensor, or EGR. To rule out what you can, d/c the vacuum lines as best you can, especially going to the MAP sensor. Then, remove and clean the IAC. You have to unhook the battery to do this and then remove the 2 screws and the wire going to the IAC. Remove it and clean it with carb/injector cleaner ( spray can) and clean any carbon deposits off the area the valve sits in. Do not squeeze the spring on this, just clean off any carbon and install. Reconnect battery and start up. Let it idle for a while. See how it runs for a day or two. If no improvement then check for codes again and see if any turn up. You can easily replace the EGR and MAP if there are more codes, but will cost 80-100 bucks (which is cheap compared to most). Check Advance auto's online parts service. You can look up and see the parts I am talking about. Really would get that Haynes manual. It does offer some other information on your codes...
http://www.partsamerica.com/ProductD...pe=282&ptset=A
http://www.partsamerica.com/ProductD...pe=757&ptset=A