jfiggy86

Hey all...my first post. Looking for any insight....1996 Civic EX 1.6 Vtech. Just starting getting pretty bad where when the car is started cold it will achieve its own idle speed. If I mash the pedal to the flow it will backfire a bit through the intake and not start until the 3rd or 4th long crank. Once started it might miss for a about two seconds but then it's just fine.

And no there's no connection to rain, high ambient temps. The only constant is that is only happens when the car is stone cold. If it's been driven to operating temp and shut off for two hours it usually fires normally.

I unfortunately have not done anything like let it crank and crank without me mashing the pedal and then pulling a plug to see if it's fuel-soaked. But the backfire through the intake makes me think the Vtech might be getting stuck advancing valve-timing? Dunno, just grabbing at straws here.

wmac

sounds like timing belt jumped a tooth, maybe

Luserkid

This is usually caused by not getting enough power to the ignitor. We had this problem for a good while before we found that out. Could also be a very weak ignitor. Check your wiring while cranking and see if it keeps a steady batt voltage while cranking.

sohctodohc

i just rebuilt a d15z1 and was having this problem turned out. when i put the timing belt on i was off a tooth. and the car would run but backfire through the intake and just had no power what so ever. hope this helps

jfiggy86

Thanks for the ideas...put a timing belt and associated parts on this car some two years ago and no problems.

And sorry for all my typos in the first post...but it looks like you've all read through them and filled in the blanks.

The car runs perfect otherwise, great power, never a backfire once it's running. Feels like a leaky injector issue or something, soaking a plug or two with fuel. Because once it's running it's prefect, no driveability issues whatsoever occur.

Also I left out that when it's cranking it does sort of sound like an engine with no compression...or one that has it's plugs out. You know an oddly super-fast cranking speed.

Former User

Have you checked the ignition timing with a timing gun?

jfiggy86

No I have not, I'm thinking that it's fine as the distributor's not been touched for something like two years and the problem did not manifest as a result of me screwing around with anything else. It's just kinda happened. And otherwise it runs perfect...just cold-blooded for the first 3 seconds it's running then she purrs like a kitten drinking milk!

Also, once it's warmed up it no longer cranks over and sounding like its got no compression, it sounds perfect.

Also, in the middle of the starting problem if I can get it to fire and then shut it off within say 5 seconds. It will crank normally and start right up...it's odd.


Modified by jfiggy86 at 12:44 PM 7/11/2008

Hriday

Lean fuel mixture...look for injector problem, vacume leak, ect....Look around the intake manny really good for broken hoses. Spray some intake cleaner around that area too. If you have access to a scan tool, check your o2 readings and that will tell you what's up.

Hriday

'Also, in the middle of the starting problem if I can get it to fire and then shut it off within say 5 seconds. It will crank normally and start right up...it's odd. "

Make sure that your main relay is clicking. I've seen perfect working main relays but ECU's still have problems closing the ground circuit. Turn the key on, listen for the click and it should fire. I've had to wait 20 seconds before it fired up before which turned out to be an ecu malfunction.

There is always the possibility that an intake valve could be sticking open. Have you done a compression check or leakdown test? How many miles on the engine? Head gasket ever been replaced...ect??

jfiggy86

Interesting thought in the intake valve...though in a long long career of fixing cars and building motors I've yet to see such a problem on my own car. But that does not mean it doesn't happen right?

But yeah, I can run a compression test and or leak down to see if there's anything bleeding out into intake or exhaust.

The thing that baffles me is that otherwise the car runs totally perfect.

Miles are around 200k, and no signs of head gasket issues, i.e., cooling system pressurized during cold starts by cylinder pressure, coolant consumption, or coolant in the oil. But I will double check the simple stuff. I've not lifted a finger towards diagnosis yet, just thought, as all cars have typical problems, maybe someone has heard of such a thing.

It's odd, but with a small amount of patience it starts up within a minute.

And the reason I noted the normal start up and cranking after the initial firing is that I was experimenting and trying to see if it would crank ok after it was running okay.

So it would go like this, car is cold, not starting...mash the pedal to floor, she spits and sputters and sounds like no compression, then starts after a few tries, run it up to 2-3k rpm, shut it down after not even having been run for 10 seconds and...

Start it again and, bam engine cranks normally, sounds like compression is good, and starts without needing the pedal floored and idles perfectly. ?????? Very odd, but I will try to do some diagnosis over the weekend. And as you can imagine it's not easy since you have to be ready to figure it out while the motor is cold. B/C once she's running she'll start just fine from then on!

Thanks a lot though for everyone's thoughts...even seasoned pros sometime miss the obvious and easy stuff!


Modified by jfiggy86 at 2:13 PM 7/11/2008