My '91 crx dx stopped running a while ago (see https://honda-tech.com/zerothread?id=1052043).

It had spark, it had compression, and it had fuel. It turns over, but it won't start. I showed it to like 6 different people. One a professional mechanic, one an ex-professional mechanic, and one friend who's an amateur/ professional mechanic. Nobody knows! I changed the spark plugs, I changed the distributor (four times), and I just finished changing the God-damn fuking engine!!...and the thing still won't start!!! What else could be wrong with this thing? Anybody have any other ideas?!

Please excuse my anger...

 

Did you check the fuel pump or the ecu?

 

What about your timing? Have you checked it? I would assume that the professional mechanics would have, but it's a start.

 

Try a new ecu?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Did you check the fuel pump or the ecu?</TD></TR></TABLE>

I checked the fuel pump the ghetto way....undid the bolt at the filter and watched the fountain of fuel squirt out. Also, I undid the intake manifold and watched a cloud of fuel mist forming. I also tried spraying starter fluid into the manifold. Nothing, it's liek the engine didn't even try firing. Is this a good enough test for fuel?

The ecu...no, I did not check. Someone told me that the chance of an ecu goin gbad is so low that it's not even worth checking....

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">What about your timing?</TD></TR></TABLE>

We messed around with the distributor while trying to start it. Nothing. It seemed like it would make a slight attempt, sometimes, at firing when we turned the distributor wayyyy beyind what it should go.

 

You kinda checked the ECU, since the injectors are spraying. Lotsa people ckeck for fuel pressure, but that doesn't prove the injectors are spraying. Your injectors are spraying, right?

Timing belt? But you've put another engine in, so can't be bad for both...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lsos &raquo;</TD></TR><TR><TD CLASS="quote">We messed around with the distributor while trying to start it. Nothing. It seemed like it would make a slight attempt, sometimes, at firing when we turned the distributor wayyyy beyind what it should go.</TD></TR></TABLE>
Describe better what you did with the distributor? Also how exactly did you verify you had spark?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JimBlake &raquo;</TD></TR><TR><TD CLASS="quote">You kinda checked the ECU, since the injectors are spraying. Lotsa people ckeck for fuel pressure, but that doesn't prove the injectors are spraying. Your injectors are spraying, right?

Timing belt? But you've put another engine in, so can't be bad for both...


Describe better what you did with the distributor? Also how exactly did you verify you had spark?
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The injectors in this new engine are not, in fact, spraying. They did in the old, but I just found out they are not in this new one. So, I had a friend spray fuel into the manifold while I tried to crank it, and it actually fired up and ran as long as he kept spraying fast enough.

So that's what it is, at least in this new engine...the injectors aren't firing. I tired changing the computer, but all I had was an auto computer. It did the same thing: ran as long as he kept spraying fuel into it.

What causes could there be for injectors not spraying?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lsos &raquo;</TD></TR><TR><TD CLASS="quote">... Also, I undid the intake manifold and watched a cloud of fuel mist forming...</TD></TR></TABLE>OK that's what fooled me...

Maybe the injectors aren't getting power?
Injectors are supposed to get battery voltage all the time from the main relay. Check the same-color wires (black/yellow?) with a voltmeter when the key is on. Measure from that wire to ground, NOT between the 2 wires of the injector plug.

Maybe there's an open circuit from injectors to ECU?
The ECU closes the ground side of the circuit to fire each injector. Check continuity on each of the injector's plug, back to the ECU. This would be the other wire that you didn't check above. (I don't know wire colors or ECU pins for '91...)

Maybe the ECU isn't getting its timing signals?
The ECU gets signals from the CYP, CKP, & TDC sensors in the distributor. Without those it won't fire spark or injectors. Check for spark. If you get spark, then these sensors are OK.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
Maybe the ECU isn't getting its timing signals?
The ECU gets signals from the CYP, CKP, & TDC sensors in the distributor. Without those it won't fire spark or injectors. Check for spark. If you get spark, then these sensors are OK.
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The engine runs when my friend sprays fuel into it, so we have spark. I'll try to do everything else you told me. I'm sure I'll finally find the problem. Thanks for the help!

 

Well, I did everything you said to do. I checked all the injector connections and the main relay and all the wiring with an ohm-meter, and everything checked out fine. I was like wtf....how the hell can everything be fine and everything work if it doesn't work!!!!!!!???????

Then I tried to start it up again and it started.