Author Topic: No start after headgasket fix (Read 4873 times)

nigel · « **on:** November 02, 2009, 02:49:08 PM »

So I just replaced my head gasket, and after getting everything back together the car won't start. The starter engages and turns the engine until one of two things happens: either the engine and starter stop instantly, or the engine stops and the started spins for a little. I've had the battery in the car the whole time, so weak battery isn't entirely impossible, but it seems strong. Also, my crank position sensor wire is a little frayed, but worked fine before i pulled everything apart. I'm fairly sure I got the timing right, but that seems like the most likely culprit. Maybe I got the cam gears switched when i put them back on... but they looked identical, and the arrows were pointing up.
Any guesses welcome... I gotta get this running so I can get out of Buffalo before the cold weather hits.

quinn11m20 · « **Reply #1 on:** November 02, 2009, 04:02:54 PM »

Remove your spark plug and then rotate the engine. This will ensure that you have no coolant in the engine. If you do, then you know what follows.

If the engine rotates fine after that, then make sure your spark leads are in the correct firing order. Both of these will eliminate, not firing, and head gasket leak. Good luck.

nigel · « **Reply #2 on:** November 02, 2009, 04:34:01 PM »

I've rotated the engine several times. First, before I even attempted to start it, just to make sure valves wouldn't get mashed. Then after I tried starting it and failed, I tried again.
As for the plugs... Cylinder one is closest to radiator, right? I couldn't find it in the Bentley manual, but someone on here mentioned it, and it seemed reasonable.

quinn11m20 · « **Reply #3 on:** November 02, 2009, 05:21:12 PM »

Right. Number 1 is to the front. Firing order if my memory serves me is 1..3..4..2. So you know your head gasket is seated right. Thats a good thing. Now its just getting it to fire. Is your computer hooked up. I mean your DME. Any relays.... Fuel pump relay in the right way. Fuel in the tank... I am not trying to be a smart ass. I am just trying to help. I know you are frantic, I have been there myself. The funny thing is it will be something simple.

nicknikolovski · « **Reply #4 on:** November 02, 2009, 05:25:56 PM »

See if your actually get fuel and spark and check your battery. Also go back and look over your work. See if you forget anything loose, disconnected etc.

nigel · « **Reply #5 on:** November 02, 2009, 06:48:45 PM »

I have a full tank of fuel, and haven't touched any relays. Definitely went over everything to make sure all the sensors are connected, but I'll do it again in the morning. What's the easiest way to check fuel and spark?
I'm a little worried about compression... when I rotated the crank by hand, it was fairly easy. Not really easy, but easier than I remember. Maybe.

Now that i think about it, I might have reversed some of the input plugs for the coils. Like you said quinn, probably something simple.

quinn11m20 · « **Reply #6 on:** November 02, 2009, 07:03:33 PM »

Good. Take a rest and first thing in the morning when your mind is fresh take a crack at it.

The easiest way to check spark is to remove one of the plugs and have some one crank it, hold onto the plug and then fuel just sniff the cylinder of which the plug you had removed. I would do that. Hey Murphy's law states "if its stupid but works, its not stupid".

As for compression....Well as long as you have tightened all the head bolts correctly and in the correct order, I don't think that would be an issue.
For this trouble shoot I would recommend an extra set of hands. Oh and tonight if you have a battery tender or charger use it, this will also eliminate low CCA. k. Good luck.

nigel · « **Reply #7 on:** November 02, 2009, 08:46:53 PM »

All right, sounds like a plan.
I thought Murphy's Law was "If it can go wrong, it will", which also applies:rolleyes:
Thanks for the quick help, I really appreciate it.

quinn11m20 · « **Reply #8 on:** November 02, 2009, 08:47:59 PM »

No prob. Oh and Murphy's has a book on laws. You should go to Barnes and Noble to get it, its very funny.

DesktopDave · « **Reply #9 on:** November 02, 2009, 09:14:38 PM »

Bad crank position sensor will keep the fuel pump from priming. I didn't see you test for gas or spark, let us know if you have one/the other/both/neither...

Cylinder 1 is definitely closest to the radiator, be sure the coils & plug wires all match, wired 1-2-3-4 from radiator to firewall.

I'd guess that your battery is just dying from he cranking...it's a real drain on the battery but it's just a guess. The starter abruptly stopping is an odd one, haven't seen that happen on my car yet.

nigel · « **Reply #10 on:** November 03, 2009, 11:30:01 AM »

Ok, it's fixed... the plug wires were flipped. Guess I was too frustrated to see it.
About the crank position sensor, though.... can I patch it? It looks like a braided conductor over an inner wire. I'm not sure about the technical aspect of it, so I'm kinda hesitant to just patch it in case this setup is necessary. Anyone done this before?

DesktopDave · « **Reply #11 on:** November 03, 2009, 12:49:01 PM »

Good to hear. That setup is confusing.

Since the CPS is working, I'd just carefully wrap it in some vinyl electrical tape & leave it alone. The braided cover is for grounding as well as shielding so you'll want it protected from too much water incursion. It's a electromagnetic sensor...the ferrous crank wheel causes an inductive voltage spike in the coil. The ECU/DME can then precisely time the engine off the crank trigger wheel.

The CPS is overpriced for what it is, so be careful not to flex the wire too much. Like I've said, if it's bad (or even too dirty) it'll kill the fuel pump as a safety measure AND set no codes.

nigel · « **Reply #12 on:** November 03, 2009, 01:05:38 PM »

Yeah, the wire is frayed enough so that it'll short if it's flexed the wrong way... luckily it's a rather stiff wire, so I haven't had too much trouble with it yet.

I was also wondering whether anyone ahd a pic of the coolant drain plug on the engine block. The Bentley says it's back by the exhaust manifold, but I didn't/couldn't see it past the control arm, steering rack, and thick black goop.

papercutout · « **Reply #13 on:** November 03, 2009, 02:32:33 PM »

You know what we did 1st time? Put the fuel lines on the wrong way round - try that, its embarassing but SOOOO easy to do!

quinn11m20 · « **Reply #14 on:** November 03, 2009, 03:35:00 PM »

Ok. Nigel, have you done any trouble shooting? What have been the conclusions?