Hey guys, I've searched, and can't find anything quite the same as my issue. My n/a gxl has a misfire at idle (which I'm assuming is also the cause of some other problems it's having). I've set the tps, I've set the throttle, set the timing, and my air/fuel is set to high 11s, low 12s. The idle fluctuates from 625~ to 775~ and the miss is inconsistent. I've done plugs twice and the wires once. Can't find any vacuum leaks, (sprayed carb cleaner and looked visually). Any ideas on what else to check? Don't know what other info you may need. Thanks in advance.

 

Does the idle fluctuate hot or cold? Does the idle fluctuate regardless of whether the car is in gear or not?

 

It misses warm or cold. Any rpm range in neutral, can't tell while I'm driving, but I'm pretty sure it does. If I'm sitting with it in gear with the clutch in, it still misses.

 

Does it wind over constantly or erratically?

Might be best to do a compression test..(rotary one or a piston one with the schrader valve removed).

You might have a stuck or broken apex seal...

 

I don't know what you mean by "wind over" :S I don't have a compression tester, but I will try to get one and check

 

Sorry.. cranking.. to start it.

ie. is each pulse the same as the last?

 

Yeah, it starts fine, although it idles really low at first (when it's cold), and sometimes stalls unless I bump the throttle, then it revs up to 1500rpm and stays there until it warms up.

 

My car does literally the exact same thing, Iv'e done the same replacements with spark plugs and wires, even the same warm up idle drop until I bump the throttle. The miss is extremely inconsistant hey? Mine can do it 3 times a second then idle for 5 seconds without the miss. I tried to suss if something was earthing but no.... perfect compression on all six too...

 

An intermittent miss is very unlikely to be compression related (on a rotary not a recip.)

Is it noticeable when driving?

 

Extremely inconsistent haha... You have a three rotor? Last time I checked my compression, they were all sorta low, but I've done a water injection treatment since then, so I didn't know what it's at now. I moved and couldn't bring my tools with me .

Mine hesitates inconsistently at different rpm ranges, and it's not all the time either, it goes smoothly one time, then hesitates at a random rpm the next time.

 

Miss or hesitation???

I thought it was a miss I was trying to diagnose....

 

Sorry, it's a miss at idle, and I thought the miss was the cause of the hesitation, but if they're not related, then I'll deal with the hesitation later. How do I tell the difference between a hesitation and a miss while driving?

 

Unless the misfiring's really bad you shouldn't be able to feel it when driving. Although you might hear it with a loud exhaust

 

I can notice it at idle, and I'd like to fix it, in case it's a cause of other issues

 

A hesitation is a flat spot when you go to accelerate..

A miss is like a pop out the exhaust at idle and kind of a chug when accelerating. Doesn't hesitate just down on power and doesn't run smooth..

 

Well it misses and hesitates, but I wanna fix the miss and see what other issues get fixed in the process

 

Spark on all leads?

Any spark plugs coming out wet?

Were you able to get the carb cleaner spray under the UIM to where the primary injectors are?

 

I'm not sure about sparks on all leads, will check soon. Plugs come out dry. I didn't try there under the UIM, will check that soon as well. Thanks for the ideas.

 

Time for a cooling system pressure check. Your symptoms say coolant o-ring failure near the non-compression area.

 

That's possible too but I didn't want to upset anyone...

 

I haven't lost any coolant though, it's still full. Does that mean anything?

 

Best way to tell without a cooling system pressure tester is to warm the engine to operating temp with the rad cap on to pressurize the system.

Once its warm pull the plugs out and wait a few minutes. Then get someone to crank the engine while you watch for water coming out of the spark plug holes..

 

Well that's very interesting, I'll definitely be sure to give that a try. Thanks

 

make sure the EGI fuse is unplugged though or it will mist fuel out of the spark plug holes.