2001 Civic LX 5 speed. 240k miles
just got the car. Just replaced head gasket, timing belt, riming belt idler pulley, water pump, timing belt, other belts, thermostat.

It ran great, no issues, but started to blow coolant so I tore it down. Got it put together and it would crank just fine but never start. I noticed a clicking behind glove box.

I went to hook up a Bluetooth scanner up to it, then it magically started. As soon as I unplug the scan tool, it dies.

No codes are coming up, but there was a idle air control code at first start up, but no longer. checked my 2 grounds (one from battery to tranny, and one from radiator support to engine. The battery 2 trans one is crappy, new one is on the way. For now I installed a new ground wire from radiator support to engine, and a new wire from battery to the same location as the radiator support wire on the engine. That made no difference.

My battery light is also on (wasn't on before rebuild) I'm charging just over 14V, which seems good. I unplugged and plugged the alternator plug about a dozen times with no difference.

Please helllllppppppp. This thing's driving me nuts!!!

 

Just leave it connected

 

First off did it run at all after timing belt? Your sure it's not off by a tooth? These cars will not run if off by one tooth. Way to test this is unplug cam sensor and try starting it.if it starts then ur timing is off.

Also check your fuses. You did disconnect battery obviously when you made repairs right? Maybe pinched a wire?

 

Car never fired after rebuild except for when plugged in. I double triple checked timing.

If it were off by a tooth it would mechanically be out of time, wouldn't it not run at all then? A scanner shouldn't be able to fix that. I will check though

 

And yes battery was disconnected when work was done.

 

Check the main fuel relay behind the glovebox for failure. Check for proper ground on the alternator bracket.

 

It's a missing ground connection. The scanner is completing a ground connection when plugged in.

 

ok. so i replaced the main ground that goes from battery to fender to trans. i also have a ground from battery to engine (where the radiator support ground is) and a new ground from engine to radiator support.
i noticed i didnt tighten one of the alternator bolts all the way during rebuild. so i tightened that
-all of that with no difference.

a few things i noticed. when i plug the scanner in, the battery, check engine, and key light come on, but if i unplug it they all turn off. when the key light turns off, the relay behind the glove box clicks out. and my battery light is always on, even though its charging at 14+ volts.

i pulled the two relays out from behind the glove box. i didn't get a chance to replace them, but they visually look ok, not burnt or fried or anything.

the car is usually idling high. 1600-1800 rpm.

once in a while my little scanner pulls up a code still for the iac. but it never saves as a fault code. it just calls it a pending code.

 

You need to voltage drop your grounds. A test lights or just looking at the ground for corrosion isn't going to be accurate.

 

i replaced both stock grounds, and added one.


and i cleaned up the surfaces....

 

Your prob. fine assuming you cleaned them enough, but all you need to be sure is a volt meter. I have seen bad grounds on brand new cars. and those had new bolts even. I assume you prob reused yours? It takes like 10 min. tops to at least check the engine grounds.

 

There are more than two also. I had a ground on a thermostat housing cause a 96 civic to not start.

 

Well maybe someone can chime in, but from the battery there is only one cable. I replaced that one cable. That cable goes from battery, to fender well, to trans. Another ground goes from the radiator support to the engine. I replaced that also. I also ran a new ground from the battery to where the radiator support ground hooks to the engine. Maybe there's some smaller ones hiding somewhere???????

 

Re-trace your work all grounds are going to be a bolt going from the engine harness to metal somewhere on the block. Like I said you need to voltage drop it to know if it's good. If you don't know what that is. It's the available voltage from point "A" to point "B". There shouldn't be much of a difference. So put your meter at the positive terminal at the battery and check voltage at all grounds you find. You should see somewhere around 12v not running at all grounds.

 

Block or part like a bracket that bolts directly to the block, intake manifold or head.

 

Mines doin this exact same thing I know its years old but did u ever find the issue if so what was it? Thanks so much... Sale clicking from fuse box and only runs with scanner plugged in however I did no work on car it jus happend while on highway... Died than when mechanic showed up ran with scanner plugged in only smh....

 

Check and clean the ground connections at the thermostat housing. The scanner is creating a ground path by way of the OBD connector.