I was driving the other day and at a light, the car just stalled. It wouldn't fire back up. I checked pretty much everything. Fuel, air, spark, grounds, plugs, fuses, but it still won't start anymore. Any ideas? I was thinking maybe a sensor went bad, which is why I'm wondering which ones are absolutely necessary for start. Any suggestions or ideas?

no CEL, changed ECU for the hell of it, still nothing. cranks all the time, but doesn't fire up.

i have oil and gas too, so those are out of question.



Modified by JZPerformance at 12:27 AM 2/7/2007

 

I have a B series. fyi.

 

will it not crank?
cranks but doesn't fire?
fires occcasionally but doesn't run?

if you're missing a sensor the ECU will tell you via CEL. You did check for those right?

 

will always crank, but never fire up.

 

yep no CEL's, at all. it doesn't pop up, neither does it come up when i check it anyway. so im lost as to what it could be. changed ECU too, same thing.

 

have you checked for power to the injectors? (sign of main relay problems)

you said you checked for fuel, does that mean that the pump primes?

 

pumps when it should, and there is furl pressure. How can I check power to injectors? CEL would pop up if injectors were having problems too though right?

 

Unfortunatly the ECU has no idea if the injectors have power. Also the same line that powers the injectors sends power to the ECU so it knows to run the car.

volt meter probe the yel/blk wire at driver's shock tower. (pick one they are all connected)
key in run, car not running you should have battery power, if you don't replace or repair your main relay.

 

I just left home, will try that tommorrow. Thanks.

 

Since all 8 wires are yel/blk, which do I use for red and black to check for power? I did check the two wires right under the yel/blk wires. that one is showing 11.59v

 

Wire colors changed between the years with resistor boxes & the years without. Neither one of you says what year engine you're talking about.

JZ has newer one without resistor box, I'd guess.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JZPerformance &raquo;</TD></TR><TR><TD CLASS="quote">I have a B series. fyi.</TD></TR></TABLE>That covers a lot of years...

 

I have a 94 civic ex with a b20v

 

I think you should check the yellow/black wires at the injectors. Each injector has one of them, and it should be hot with battery voltage (when the key is turned on). Red voltmeter lead on that wire, black lead to ground. They're all SUPPOSED to be connected together, but verify that each one is hot.

Does the CEL come on when you first turn on the key (self-test)? If not, then check for a burned-out CEL bulb.

 

Yea, I was about to post that. I'm gonna test an injector directly, that should be the ultimate test for fuel.

Regarding CEL, it's good.

If the plug with the 8 yel/blk wires was not getting power, then wouldn't that mean injectors aren't either? I put red on the yel/blk wire and black on the chassis, and all kinds of metal, but got no reading. Is that correct? Or should I have tested it differently?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JZPerformance &raquo;</TD></TR><TR><TD CLASS="quote">If the plug with the 8 yel/blk wires was not getting power, then wouldn't that mean injectors aren't either? I put red on the yel/blk wire and black on the chassis, and all kinds of metal, but got no reading. Is that correct? Or should I have tested it differently?</TD></TR></TABLE>I'm not sure which plug you're talking about. Wires from that plug go to the injectors?

Was the key ON when you tried this?

 

Well it's weird because it's capped off with a fake female plug. It's on the same harness as the injectors. It's one of the plugs near the driver side shock tower. There are two plugs hooked on to a holster piece and it is the top plug.

Yes, key was on run. Like I said, the lower one worked, but the top one didn't. Then again, I'm not sure if I tested it right, since they were all 1 color wires.

 

didn't read the thread, don't know your problem, won't even attempt to read, but first thing's first, check compression to see if timing belt slipped, second thing is to replace main relay with a known good one and see if it starts. If neither of these are the problem, go back and read all the other suggestions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JZPerformance &raquo;</TD></TR><TR><TD CLASS="quote">Well it's weird because it's capped off with a fake female plug...</TD></TR></TABLE>Sounds like some kind of diagnostic plug. I won't guess what it's connected to without seeing a wiring drawing...

Unplug the injectors, each plug has a yellow/black wire along with another wire of various colors. Key on, the yelow/black one should be hot. The other wire in each plug is connected to the ECU, which closes the ground side of the circuit when it wants to fire the injector. Get it?

Backing up to some basics...
Your main relay is really 2 relays in one housing. One of these relays switches power to the ECU as well as the injectors, distributor, etc... If that relay were bad, your CEL would NOT light up during it's self-check. The other relay in the 'main' relay switches power to the fuel pump. If that one were bad, your fuel pump would not run for it's 2-second priming. So - I think you've shown the main relay to be good.

Just because the main relay is OK, you still might have some break in the circuit supplying power out to the injectors. That's what you're checking.

You said earlier that you have spark. (VERIFIED this??) That would demonstrate the distributor/coil/ignitor & the ECU's ignition output signal is OK. Are you sure your plug wires are connected in the right firing order?

Check whether the timing belt is completely broken, by looking into the oil-fill cap. Crank the engine & watch the camshaft spin. If the belt slipped or broke teeth, a compression check should tell. If it's GROSSLY bad, your engine would sound different while the starter cranks. You wouldn't hear the sound of each cylinder coming to compression, it would just spin fast & constant.

Future work? We gotta think of other systems to check & keep checking until you find something that's screwed up so you can fix it.



Modified by JimBlake at 12:20 PM 2/8/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JZPerformance &raquo;</TD></TR><TR><TD CLASS="quote">Well it's weird because it's capped off with a fake female plug. It's on the same harness as the injectors. It's one of the plugs near the driver side shock tower. There are two plugs hooked on to a holster piece and it is the top plug.

Yes, key was on run. Like I said, the lower one worked, but the top one didn't. Then again, I'm not sure if I tested it right, since they were all 1 color wires.</TD></TR></TABLE>
that female like plug is actually a shorting bar. It connects all the connections in the plug together.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Relic1 &raquo;</TD></TR><TR><TD CLASS="quote">
that female like plug is actually a shorting bar. It connects all the connections in the plug together.</TD></TR></TABLE>AHA! That's how they branch all those circuits off the main relay. There's ONE wire in that bundle which should be hot without the cap. All the others aren't hot UNTIL THE CAP IS INSTALLED.

If you can't find ONE hot in the bundle, then you have to look further 'upstream' in the circuit, for a broken connection somewhere.

 

sweet, thanks for all the help so far.

yea, I'm sure distributor and firing order is all correct. Like I said, the car was running perfectly, and one day at the light, it just decided to stall and never wake up again. =/

So pretty much I'll check compression and make sure the timing belt didn't slip or something.

Then check to make sure injector plugs are all hot, and also the one wire on the plug that should be hot.