nickblackbelt

iTrader: (5)

99 miata
60k miles
ran great then stalled at a light
no turbo
no start
backfires out of the intake.
i replaced the cam sensor, and spark plugs. i also put a new to me coil pack on. i can hear the fuel pump and smell gas after cranking. the crank bolt is tight, the timing is dead on and tight.

i tried a compression test and i got #1 60 #2 90 then i gave up because i guess i could not get it on tight. i just did the head gasket with arp studs/timing belt(after doing this it ran for about 1month great till this happened)

fooger03

iTrader: (2)

You are frakking HORRIBLE at describing symptoms.

Help us help you. Take a few minutes to write out your problems in a good chronological and sequenced order:

My money is on you not properly tensioning your timing belt. Your intake cam has slipped several teeth relative to your crank.

fooger03

iTrader: (2)

Thats better.

If you're backfiring out of the intake, your timing is FAR from dead on.

Either that, or one of your cams is broken.

p.s. Next time you ninja edit to fix something I called you out on, I'm going to kick you in the nuts.

nickblackbelt

iTrader: (5)

hahaha, but the timing on the 99 is not adjustable? the cam sensor is not adjustable either.

Joe Perez

iTrader: (8)

Given the combination of backfiring out the intake and the very low compression numbers on cyl #1, could it be that you have an intake valve which is burnt / stretched / otherwise not seating properly?

If you have access to a leakdown tester, now would be the time to use it.

EDIT: I just re-read everything and saw the "no start" part of the problem.

Are you absolutely, 100% certain that your cam timing is correct? I've never seen it happen personally, but stories abound about loose cam belts jumping a few teeth.

fooger03

iTrader: (2)

Of course the timing is adjustable - in 1 tooth increments.

When you say "the timing is dead on, and tight"

"the timing" refers to the positions of the intake cam, the exhaust cam, and the crank, the spark time, and the injector pulse, all relative to one another.

Since your intake cam is matched to your camshaft angle sensor on the '99, we can determine that your intake cam is not rotationally aligned with at least one of (if not all of) the aforementioned parts or processes.

nickblackbelt

iTrader: (5)

well when i did the head gasket a while back i did the valve seals and its been running great till now. the timing belt is on

fooger03

iTrader: (2)

OF COURSE the timing belt is on. Without the timing belt on, you wouldn't have backfiring because you would have no firing at all. You also wouldnt be injecting any fuel.

What we're saying, very pointedly, is that "the timing belt is on incorrectly". We are not suggesting that you put it on wrong, because as you mentioned, it obviously ran after the timing belt change. We are suggesting that the timing belt has slipped across one of the three pulleys that it operates about. Your symptoms are congruent with the diagnosis, and you have yet to give us reason to believe otherwise.

nickblackbelt

iTrader: (5)

i said timing belt on as in its on the right way and tight i checked it

lordrigamus

iTrader: (14)

Meaning all your timing marks still line up correctly, right?

nickblackbelt

iTrader: (5)

yes. i also just ordered brand new coil packs and a new crank sensor.. there gos 300 bucks

lordrigamus

iTrader: (14)

You should do a compression test on all cylinders. You should also quit ordering random parts till you diagnose the problem.

Joe Perez

iTrader: (8)

A couple of diagnostic tests might be in order here, before you go blindly throwing parts at the car.

1: Have you tried removing the voodoo box, and any other electronic mods?

2: Have you plugged an OBD-II scanner into the car to see what it has to say?

3: Do you have access to a leakdown tester?

edit: lordrigamus beat me to it.

lordrigamus

iTrader: (14)

Maybe, but yours was more detailed and informative. I yield the floor to you, sir.

nickblackbelt

iTrader: (5)

1. yes i removed it and put it back on. it stalled and would not start before i turboed it.
2. yes and no codes
3. no how much? how does it work

flounder

Can you run those compression numbers by me again? What's #1 60 #90 mean?

Do you have access to a scan tool?

nickblackbelt

iTrader: (5)

yes i have a obd II reader and theres no codes. i did not do the test because i could not get it tight in the spark pulg hole

lordrigamus

iTrader: (14)

Why? Is it one of the ones you have to hold in the plug hole?

nickblackbelt

iTrader: (5)

it screws in. its brand new from harbor fright
the cheapest one, heres the link
http://www.harborfreight.com/flex-dr...ter-92697.html

flounder

Is it one of those cheesy push on ones or is it a threaded tester? Either way those numbers are way low.

Like another poster said, leakdown test sounds like the way to go. Make sure your at TDC on the cylinder(s) you're testing and keep the regulator set below 50 psi. Listen for air exiting from the throttlebody or exhaust pipe.

Your sure all the timing marks are correct?