kylelovesbass

Hi guys, I have a 1990 Accord EXR with a no start problem that I'm 99% sure is ignition timing related. I bought the car cheap thinking this would be a pretty easy fix, but it has been very difficult. The car was running fine until it died all of a sudden according to the previous owner.

I'm pretty sure it must be a timing issue because when I switch a distributor wire from say cylinder 1 to 2, I can feel the engine firing at the wrong time and slowing itself down when trying to start, so I know there is combustion happening. The question is what is throwing the timing off. Otherwise with the spark wires hooked up properly the engine doesn't catch at all.

The odd thing is that if I retard or advance the distributor timing all the way it will occasionally start and run for about 5 minutes until the idle slowly drops too low and the engine dies. The engine will run rough and misfire every 2-3 seconds during this period, rotating the distributor (even beyond the bolt holes in both directions) does not make it run smoother. It will not start again when warm.

Here is the exhaustive list of things I've tried so far that have not worked. I have thoroughly read every no start FAQ guide I could find online:

-Triple checked mechanical timing, it's dead on. Cam pulley marks line up with top of head at TDC. I even moved the cam pulley a tooth off in either direction to see if the car would run, didn't help.
-Checked cam pulley key, it's fine and pulley is aligned properly with the camshaft
-Distributor swapped with two other working units just to be sure
-Ran the distributor power wire directly to the battery just in case it wasn't getting enough voltage/amperage
-Removed distributor cap and rotor is pointing to cylinder 1 at TDC
-Grounded several areas of the engine directly to the battery with a jumper cable
-Spark plug wires are hooked up correctly
-Tried rotating the distributor beyond the bolt holes in both directions, no change, but occasionally the car sputters to life when I do this
-Spark plugs swapped
-Spark wires swapped
-Fuel drained and fresh gas put in
-Fuel pressure around 50 psi
-Fuel flow rate seems good. To test, I removed the return line and hooked up a clear hose into a bucket. Turned key to prime, lots of fuel coming out
-Good steady injector pulse
-Good strong spark
-ECU swapped with good working unit
-CTS, MAP, TPS, IAT, IACV all tested. I even unplugged them one by one so the ECU would ignore them in case one was the problem.
-Unplugged the knock sensor, no change
-EGR system is fine, not stuck open
-No signs of vacuum leaks, when car does start from cold it idles around 1500 rpm where it should
-Compression tested at 175psi across all cylinders. Leak down is good.
-No check engine light. Light is working and comes on when I disable sensors
-Lots of cranking power from battery/starter, cranks over at a normal rate
-Main relay replaced and tested

Please help, have I missed anything? I'm all out of ideas!! Have you had a similar problem? Something must be throwing the ignition timing off.

Thanks guys!

kylelovesbass

Some more info, got it running for a while today. It starts and runs (poorly) with the distributor advanced past the bolt holes a bit. It will misfire constantly though. Checked timing with a timing light and when I move the distributor where it should be, it dies. I can see the 15 degree mark come into view when I move the distributor around the middle before it dies, so this tells me mechanical timing must be ok. Still stumped here.

holmesnmanny

Hate to say this but I really gotta ask, are you 1000% you got the firing order correct?

kylelovesbass

Yes, I checked it a few times. I have another Accord EXR in good working condition and I double checked to make sure it was hooked up the same. I know the firing order is 1342 and I can see that the plugs are hooked up this way when the dizzy rotor spins. I even tried swapping the wires all sorts of different ways, sometimes it would backfire but never made it any better. I wish the problem was this simple

This car seems to have the symptoms of a timing belt that has skipped, but mechanical timing is perfect. The only way I can get it to run (poorly) is to advance the dizzy a bit past the bolt holes.

I also checked all the dizzy sensor connections to the ecu, all good there.

holmesnmanny

What color is your spark ?

kylelovesbass

Appreciate the input.

Looks like a good white/blueish color most of the time, sometimes a bit darker. I video recorded it on my phone, then compared it to the spark on my good running Accord and they looked the same. The dizzy has been swapped for a couple other good working units and I even hooked power up to the dizzy directly from the battery, so I'm not sure how the car could be getting weak spark (I'm not ruling this out yet), any other ideas of how it could be getting weak spark?

I'm also thinking this may still be a knock sensor issue, if this car even has one. I looked on the back of the engine and there is a red 3 prong sensor near the oil pressure sensor. I figured this must be a knock sensor. My other Accord does not have this sensor. I thought unplugging the knock sensor would make the computer ignore it, but from my quick google search it seems that the computer will still default to a very retarded timing.

kylelovesbass

Ok so it looks like I actually have a weak spark for some reason. I pulled the wires at the dizzy cap and the orange colored spark barely jumps a couple millimeters. I did the same thing on my other good running accord and the spark jumps almost an inch and is bright white!

Now I just have to figure out what's causing this. It's not the distributor or power going to the distributor, so could be a bad ground or something else. Will post when I find the problem.

Funny because I grounded the engine directly to the battery with jumper cables and it didn't run either, so I don't see how it could be a bad ground, any tips here would be appreciated.

kylelovesbass

SOLVED!!! I can't believe what the problem was... the stupidest thing ever. It was a bad rotor inside the distributor causing the weak spark. WTF! When I swapped in the distributor from another good working car I used the same cap and rotor from this car, so that's why it didn't solve anything.

That took WAY too long, I think I spent like 10 hours on this car.