1995 Prizm didn't pass smog due to timing???

[redgtxdi]

So aside from my ignorance, I was surprised to hear that my Prizm didn't pass smog due to timing. (Supposed to be 10 degrees but mine was 4 degrees?)

I asked the guy if it was ignition timing & he said, yes, but when I asked if I could just throw it on a timing light & adjust, he said that it's also sometimes that timing chains skip a tooth or so.

Now, I *think* mine has a timing belt, but maybe you guys could straighten me away & throw some advice my way??

1995 Geo Prizm 1.6L w/ 3-speed (slowest slug west of the Mississippi)

TIA

[Bitter]

yes, it should be 10 btdc
don't know if timing jumped a tooth would affect it as he thinks it would, but it would run poorly out of time like that.

[redgtxdi]

And to be sure...the 1.6L still uses a timing belt right? I haven't done anything regarding the timing belt since I bought the thing 5 years ago and I wondered back then if it needed one. Obviously if it has a chain it don't really matter.

But if it does have a belt I'd be surprised if it slipped without starting to slap the belt guard. My Camry did that something fierce back when it needed one.

???

[ganda1f]

Yes, 1.6l 4AFE engine has a timing belt. If the belt skipped a tooth, both your camshafts and your ignition would be out of time. Distributor is driven by one of the camshafts.
From experience with my car, the ignition timing can change by at most 1-2 degrees during the 60k miles belt change interval. Due to the timing belt stretching over time and use.
If the timing is off by as much as 6 degrees (and has previously been correct at 10 BTDC), I am willing to believe that the timing belt has jumped a tooth.

But as Bitter said, I am not sure how that would affect emissions.

[Bitter]

make sure you're checking the ignition timing correctly with the diag jumper.

[redgtxdi]

FWIW I had no idea timing was a smog-weighted criteria either but this is California & this state is about as bassackward as they come. If it's really a cause for concern then I'm thankful they noticed but I certainly don't think it should have kept me from passing smog. (whatever)

Bitter, can u help me with your comment about checking timing?

Thx again

[Bitter]

just google search about advancing timing on a corolla, its also the procedure to check/set timing.

[redgtxdi]

Here's looking down on the pulley timing plate w/ the marks on it. Looks like there's 4 + an arrow. Assuming each mark is 2 degrees, that arrow would be 10 degrees, eh? Mine was right where I put the red mark at idle using my timing light. (so approx 5?)



I just want to show these next 2 pics to make sure of the bolts but to also show that the bottom phillips screw (circled in red) on the distributor was backed out quite a ways. I tightened it back up but have no idea if that might have had any bearing on the timing changing or not. (Also noted bottom (front) bolt to loosen for timing. (circled in blue)



Lastly, tried to get a shot of the back bolt. (circled in red again). That sucker's gonna need one of my skinny wrenches to get at. (Evil engineers will stop at nothing to bloody up some knuckles). I did my checking w/o jumpering the TE1 E1 thing, but took note of them in the diagnostics box. Wanna see what y'all think of my situation & whether I should adjust at distributor first or assume that timing belt's jumped a tooth. TIA!

[ganda1f]

Originally Posted by redgtxdi

Here's looking down on the pulley timing plate w/ the marks on it. Looks like there's 4 + an arrow. Assuming each mark is 2 degrees, that arrow would be 10 degrees, eh? Mine was right where I put the red mark at idle using my timing light. (so approx 5?)

The marks are at 0, 5, 10, 15 degrees. At least on the Corolla they are. Can't imagine why this should be different on the Prizm. 5 and 10 are stamped on the plastic piece. Arrow being 20BTDC

Originally Posted by redgtxdi

I just want to show these next 2 pics to make sure of the bolts but to also show that the bottom phillips screw (circled in red) on the distributor was backed out quite a ways. I tightened it back up but have no idea if that might have had any bearing on the timing changing or not. (Also noted bottom (front) bolt to loosen for timing. (circled in blue)

Circled in blue is one of the two bolts you need to loosen to turn the distributor. No need to touch the phillips screw.

Originally Posted by redgtxdi

Lastly, tried to get a shot of the back bolt. (circled in red again). That sucker's gonna need one of my skinny wrenches to get at. (Evil engineers will stop at nothing to bloody up some knuckles). I did my checking w/o jumpering the TE1 E1 thing, but took note of them in the diagnostics box. Wanna see what y'all think of my situation & whether I should adjust at distributor first or assume that timing belt's jumped a tooth. TIA!

That bolt is the second one that needs loosening to turn the distributor.

Adjust the ignition timing first. You MUST do it with TE1 and E1 jumpered. If the engine runs OK after that, the timing belt is probably how it should be. Valve cover has to come off if you want to have a look and make sure.
Don't know if the engine would run poorly enough to notice a single tooth jump, just by listening to it. I have not experienced it myself on that particular engine. Bitter, maybe you could elaborate on that.
However, from your pictures it looks like your ignition timing is 8 degrees BTDC and not 4. That would rule out the possibility of the belt jumping teeth. 8 degrees is actually within the specs, judging from the sticker in my Corolla. Sticker says 10+/-2 degrees.

[redgtxdi]

Wow, thanks for the feedback gandalf!!!!

I didn't even think about it but that sure makes sense. Those being 2-degree marks would probably make that one HUGE pulley to get to 360 degrees come to think of it, eh?

So, then if even at *worst* I'm at 7 or 8 degrees, I wonder why their smog equipment would've shown me at 4??

Maybe I should kick the idle adjustment up a tad??

Or maybe go ahead & adjust up anyway to get a solid 10 degrees & see if the idle kicks itself up & sits more steadily at 10 or so during their next check?

[speedy25]

If your timing belt is LOOSE the timing can jump around at idle.

-SP

[Bitter]

timing will retard and advance itself at idle or when the engine is running, when you jump the connector you're STOPPING it from changing ignition timing so you can set it/check it. I doubt they jumped the connector to check base timing.

If the engine were a tooth off it would either idle very poorly or have no power at higher engine speeds due to the cam shafts being advanced or retarded in relation to the crank.

[redgtxdi]

OK, and mine definitely doesn't exhibit either of those traits. Still, I wonder what's going on or if my timing isn't really off at all & their equipment is reading wrong? (Though that would surprise me, but who knows)

I'll probably go with my instinct & advance the timing a bit to get it to *at least* 10 & hopefully that'll satisfy their machine. (again, unless there's something wrong)

Thanks so much for all the help!!

Originally Posted by Bitter

timing will retard and advance itself at idle or when the engine is running, when you jump the connector you're STOPPING it from changing ignition timing so you can set it/check it. I doubt they jumped the connector to check base timing.

If the engine were a tooth off it would either idle very poorly or have no power at higher engine speeds due to the cam shafts being advanced or retarded in relation to the crank.

[redgtxdi]

Wow........so I couldn't see squat on the timing hash-mark plate cuz it was dirty and so I decided to reach in there & wipe it off.

Well, it doesn't have 0, 5, 10, 15, 20 marked on it.......BUT......It DOES have a BIG FAT ****10**** plastered right in the middle hash mark on the plate.

Now, knowing what I saw when I checked the timing with my light the other night there is NO WAY mine's at 4 BTDC!!! NO - FRIGGIN - WAY!!! (Again, I'd guess between 7 and 8 BTDC)

Soooo.......do I call them on it, or do I just up the timing a couple degrees & see if that pacifies their equipment???

(I'll post a pic in a little bit. No doubt that is the biggest, fattest "10" on there, for SURE!)

[Bitter]

call them out on it :p

some late 1995's did not have adjustable timing since they were in the same emissions spec as the 96 and higher **or so I've heard**