1995 MX6 V6 Turns over but does not start

[mob]

I am new to posting on forums in general so my apologies ahead of time if I don't get everything quite right.

Background:
My 1995 MX6 was working great until about a year ago when it started to stutter and lose power when exceeding approx 3500rpm. I dont recall everything that I checked but for some reason I pulled apart the distributor to inspect for damage etc.., not removing it from the engine, then reinstalled. After doing this the car would turn over but not start.

Details:
Codes: 29, 41
Have spark
Have fuel: smell it on all plugs and from intake.
Replace with Distributor, Rotor, & Cap (yesterday)
Replaced fuel filter (3 months ago)
New spark plugs & wires

Checked for TDC at cylinder 1 and compared to rotor position, this seems a little off to me, shouldn't the rotor be pointing directly at spark plug number 1on the distributor?

Mine appears to be about 30-40 degrees before spark plug #1 when cylinder 1 is TDC compression stroke and pulley mark lines up with "T" on the engine block. Perhaps the timing belt has slipped? I have not heard any severe or strange noises from under the hood.

Could codes 29 & 41 prevent starting?

Any help would be greatly appreciated,
Thanks in advance.

[mob]

I have tried to adjust the distributor position to compensate for the rotor not pointing directly to spark plug # 1 --- 30Degrees prior to the spark plug on the distributor is the best I can get.

I did try pulling the distributor out and moving the rotor position but it seems the distributor is keyed to fit in only one position.

I also pulled all the spark plugs and poured a small amount of oil down the holes in the event things weren't sealing properly...no luck.

Any other suggestions?

Thank you,

[mob]

Originally Posted by mob

I have tried to adjust the distributor position to compensate for the rotor not pointing directly to spark plug # 1 --- 30Degrees prior to the spark plug on the distributor is the best I can get.

,

Here is a photo representation of the position. Red pen indicates spark plug #1 position.
https://picasaweb.google.com/1095409...36814127338642

Thanks.

[PaulG]

I would guess that your timing belt has jumped. I think you can take the upper bolts off of the timing belt covers and peel them back to see if the timing marks line up.

[mob]

Many thanks for the reply. I will try to check this out later today.

Do each of the camshafts have a timing mark notched into the side of the gear or am I looking for some other sort of mark?

When the #1 piston is at TDC compression should all of the marks line up?

Just to for clarification TDC is when the # 1 piston reaches its upper most limit then starts to come down again on the compression stroke, is that correct?

Thanks again.

[PaulG]

Here's a link showing timing marks: Welcome to Probe - MX6 - Tuning section

If you compression test the motor and find one bank of cylinders has worse numbers than the other, that'll be an indication of mechanical timing being out as well...might be quicker than peeling back the timing covers and possibly removing the crank pulley to check that mark behind the crank pulley.

[mob]

PaulG,
Thanks for the link, a lot of good info on the probe-Mx6 site.
Ok, that sounds reasonable... and might save a little time. I will try that first ... once I pickup a compression test kit.

I will post my findings.

Cheers,

[mob]

Finally got a chance to do a compression check on the MX6: Here are my findings.

Compression readings not looking so good :-(
Compression should be around 200psi on each cylinder with a low of 140psi, I am assuming that this is with a hot engine. So, with a cold engine here is what I have:

Dry Compression Test:
Back Bank (near firewall)
1= 120
3= 120
5= 120
Front Bank
2=140
4=135
6=125

Wet Compression Test:
Back Bank (near firewall)
1= 140
3= 135
5= 130
Front Bank
2=155
4=150
6=165

I have read that you should compensate 10-15% for a cold engine... any thoughts on that?

Could this difference between front and back banks be accounted for by a timing belt slippage (earlier post)?

Looks like some blow by on all cyclinders, to be exptected as the engine has 269K on it, any thoughts on this...?

primary object right now is to get the car running so I can get it down to have it inspected before the end of the month. Then address a possible rebuild.

Any thoughts, insights or suggestions are welcome and appreciated.

[PaulG]

I would look at the timing. It could be (fingers crossed) that both banks are off by a tooth or two, giving you low compression.

[mob]

Hopefully thats the case and seems to make sense as it was running before I messed with the last distributor.
Sounds like a plan, thanks Paul.

*Hoping to do this soon and will try to document/post results.

[PaulG]

All you did was mess with the disty before the no-start condition? Maybe it wasn't put back together properly? How much of it did you open up? Just the cap and rotor, or the guts of the disty too?

[mob]

I pulled the guts of the old disty apart, inspected then re-assembled. Then no start condition. Then I replaced the disty and still no start condition. That was when I started looking at timing and TDC and noticed that the rotor position appeared to be off at TDC compression stroke.

Last night I reset the ECU (Pulled pos & neg battery leads and shorted them) and pulled the engine codes again. (previously cleared alarms by pushing brake method, perhaps that didn't clear things out properly?)

41 remains.
29 is gone replaced by 03

With 03 (camshaft position sensor) ... now I'm not sure that the new disty is any good, or could be the wiring harness.

Is there a good way to check the wiring harness going to the disty?
I have read that people have done it but not seen any details as to how.

Of course it still might be that the timing belt slipped or jumped a couple of teeth, I believe it hasn't been changed in about 120K ... and this new development just coincidence

[mob]

Originally Posted by mob

Then I replaced the disty and still no start condition.

Replace the old disty I pulled apart with a new disty purchased on ebay

[PaulG]

A lot of people get DOA distys, whether new or used...can you warranty that disty? Or do you have a friend with a 95-97 mx6/probe/626 who will allow you to try their known working disty?

[mob]

Yes, I think it has a 90 day warranty... will try that route too. Unfortunately, don't know anyone around here with a compatible disty. Thanks.