96 SC1 code 301

tepose · #1 03-21-2009, 05:59 PM

I have a 96 SC1 that puts a code 301. I know it's an intermittent misfire on cyl 1. I have replaced the coil, wires, plugs, and module. It still throws a code 301. Even swapped coils, plugs and wires in case they were bad from stock but still stays on one! Could it be in the computer? At a loss. Any help would be appreciated. Tom

discnik · #2 03-21-2009, 10:51 PM

A bad fuel injector can also cause a misfire as can low compression, (Below 100 psi), in the cylinder.

Do a compression test on the cyclinders. Using a stethiscope or long screw driver listen to see if the solenoid in the injector is clicking with the engine running, if it is not, straighten out the filament wires on a "197" light bulb and plug it into the injector electrical connector to see if it lights when the engine is cranked to insure that voltage is reaching the injector.

Always make sure to keep clothing and hands away from moving parts when working on a running engine.

Let us know how it goes.

RC1488 · #3 03-22-2009, 08:55 AM

SOHC are known for cracked heads. Remove the valve cover and inspect the head near the 4th cylinder journal. Your looking for a small hair line crack.

Also take brake cleaner and inspect the intake manifold gasket. Though not as common on 2nd gen SOHC, they are common to go bad on 3rd gen SOHC. Listen for idle differences as you spray around the gasket at each cylinder.

'96 has been known to throw this code bc of a crankshaft relearn disfunction in the new OBD II PCM. If the the above does not work, you will have to go to a GM or Saturn dealer and have them force the PCM to relearn the crankshaft. Usually this is needed if a new engine was placed in the car, but everynow and then this is needed regardless if the engine was changed.

saturntech · #4 03-22-2009, 02:51 PM

After changing all that stuff, is it still cylinder 1 that is misfiring, or did it move to a dif cylinder

tepose · #5 03-22-2009, 08:08 PM

No matter what I do it stays with the 301. It also has a 507 which is a high idle. After reading the other posts associated with a 507, I believe there is an intake gasket leak at #1 as the idle does smooth out when sprayed. The idle stays at around 1300. I removed and cleaned the throttle body which was extremely dirty. The IAC was replaced. MAP is new too. Replacing the intake gasket seems likely to fix the 507 but still noy sure about the 301.

RC1488 · #6 03-22-2009, 10:21 PM

Quote:

Originally Posted by tepose

No matter what I do it stays with the 301. It also has a 507 which is a high idle. After reading the other posts associated with a 507, I believe there is an intake gasket leak at #1 as the idle does smooth out when sprayed. The idle stays at around 1300. I removed and cleaned the throttle body which was extremely dirty. The IAC was replaced. MAP is new too. Replacing the intake gasket seems likely to fix the 507 but still noy sure about the 301.

New gasket will fix the high idle and misfire code. Rockauto.com is where I got my gasket. Heres a how-to for a 3rd gen car. Almost exactly the same procedure:

http://www.automotiveforums.com/vbul...d.php?t=895826

tepose · #7 03-24-2009, 11:10 AM

Thanks for your help. I am changing the intake gasket this weekend and hopefully that will fix it. I'll let you know. Tom

tepose · #8 03-29-2009, 07:38 PM

Changed the intake gasket, deffinately blown near cyl #1. Idles around 600 rpm now, no codes. So fsr so good. Thanks for all your help. Also had the job done for only $150 by a liscensed mech. Why do it myself at that price. Thanks again.

RC1488 · #9 03-30-2009, 05:28 PM

Quote:

Originally Posted by tepose

Changed the intake gasket, deffinately blown near cyl #1. Idles around 600 rpm now, no codes. So fsr so good. Thanks for all your help. Also had the job done for only $150 by a liscensed mech. Why do it myself at that price. Thanks again.

Because doing it yourself would have cost you $20

Glad you got it working though

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