so i finally got my first third gen 89 iroc, 305, 5spd, so when i test drove the car it ran fine and all, before i bought it the guy told me that the engine light comes on from time to time. when the engine light comes on it literally bogs and has no power, but when its not on that thing GOES!!!!! so what im asking is this a sensor issue? it has to be right? but why does it come on if the car runs totally fine? im thinking it needs a new sensor but thought i would ask you guys before taking it to a mechanic

 

There's an easy way to tell what the problem is. It's called "checking the codes." It's been covered a bajillion times.

You just have to take some wire, like a paper clip, and jump some pins together on the ALDL/OBD connector (that's the 12 pin connector near your knees). Connect the top row - rightmost 2 pins together with key off. Then key on without starting. You'll see the check engine light flash and pause. You'll have to count and write down what you see. You should see 1__1_1____1__1_1____1__1_1 when all is normal (that's 3 twelves). Then your trouble code will flash its number 3 times. When it does 12 again, it's done. Key off, and remove the wire. Then just do a search for the trouble code that you have, and follow the diagnostic procedure found in any good repair manual.

 

so i took her out for a spin and about 15 minutes after starting her up the ses light came on and i checked the codes this is what came up...code 42 and 45, after searching on the forums a bit 42 is mainly a timing issue and 45 is running rich??? i guess it makes sense that these two are going off, the only thing is since i am totally new to this stuff, how do i check the timing, any links would be appreciated

 

42 is usually an ignition module fault. Could also be the EST Bypass wire that lets the computer control the timing (Tan/Black wire) being frayed or grounding out, but probably wouldn't be so predictable. ULTM8Z is having a similar code 42 problem on his car. Maybe check his posts.

45 might come from the 42 fault since it's retarding a lot. Fix 42 first. Clear your codes (disconnect battery for 30 seconds), and then check your fuel pressure. If fuel pressure is OK, and still has code 45, might as well replace your O2 sensor, and clear the codes once again. After that, if still a code 45, your MAF might not be getting a good burn-off (but would probably create lean not rich fault), or is just old.

 

alright so i guess ill look into getting an ignition module, see if it works or not, any recommendations on what kind to get?

well since im new i apparently missed a few codes, i now have a code 14 and a code 22 going off as well are these in anyway related to the 42 and 45 that keep coming up?

 

threw in a new ignition module and she drove beautifully for the first hour or so and then she threw a couple codes...14, and 42. Does this mean that it has to be the bypass wire? or are there anythings that i have missed that i should check out again...

 

Uh oh, I'm guessing your coil is a little bad, and maybe damaged your new module...
Live and learn.