Working on my in-laws 2004 Honda Civic LX 1.7L L4 SOHC 16V, about 165,000 miles.
A couple weeks ago they went to drive it and it acted like throttle was stuck, he started it, it stuck, he parked it and shut it off. Started it again a couple times and eventually tried slamming accelerator quickly and let off, and it died. He tried to start it back up, and it would crank but not turn over. That's all it's done since. I checked the timing, it's dead on. The spark looks maybe a little weak but it's there. I removed the air filter and hit it with starting fluid, does absolutely nothing. I've checked most of the fuses under the hood and dash and they've been fine. It'll crank just fine, a bit slow without the booster at this point because we've tried so much haha. No codes last we checked. I've got loads of wrenching experience and am comfortable with doing just about anything to this thing. Any ideas on what's wrong?

 

The strangest part to me is that it doesn't even try to fire on the starting fluid, not even a tiny bit. We also haven't done a compression check yet due to not having a tester, but that's on the list.

 

If it won't even fire with starting fluid, then it either doesn't have spark, or the spray isn't getting to the spark plug end somehow. Have you tried spraying directly into a cylinder?

 

I did not spray it directly into a cylinder, but the exhaust smells like starting fluid so I know it's going through the system. You can feel it pulling air in through the throttle body, so I know it's got air. A friend suggested today maybe the tps is bad and has the ecu confused on spark timing and maybe it's just too far off to start. Anyone know what the spark timing should be for when I check it with a scanner?

 

Worked on it some more tonight. Timing was about 5⁰ according to the scanner. Despite nothing changing since last time it's acting different now...Every now and then it would try to fire, when holding the pedal down (deflood mode) it would try much more often but starting fluid still made no difference and it never quite caught. Last time it never tried even the slightest, so we're pretty confused.