2GN.ORG

It started ok this morning then 2 minutes later, no power!
Engine making nasty clicking noise and if I accelerated hard it would pickup speed but loud clicking from engine and popping from exhaust.

Slowed down to stop and engine died, won't restart.
Making the right noise like it wants to start (not just clicking like dead battery)

Don't know if it's related but AC lines were iced up but I didnt have AC on!

I suspect ignition problem? Spark plugs changed 8k ago and wires 30k ago. Coil is the one it was built with,

Please help

sounds like it could be also a sensor problem.
have you tried the key-dance to get cell codes?
(Ignition on-off-on-off-on - watch the odometer)

I didnt try that, I had to rush to work in the other car, will try later. But the light didn't come on.

Possible timing belt slippage?

IDK if the A/C is related to the exhaust noise, or not. The relay might have stuck on. Try pulling the A/C relay for that.

Cam sensor ?? Should throw a code tho ...

occasional demons wrote:Possible timing belt slippage?

IDK if the A/C is related to the exhaust noise, or not. The relay might have stuck on. Try pulling the A/C relay for that.

I hope it's not timing belt related, only changed all that 8k ago!

Would the relay cause it to Ice up in only a couple minutes?

If the A/C compressor is not shutting off, it will basically just keep cooling until something gives. Possibly the system pressure is what's dragging the engine down, trying to turn the A/C compressor. Maybe you have an exhaust leak which is making the noise, due to the load on the engine. The A/C clutch may have welded itself together also. either pulling the relay or removing the drive belt should tell you if it is/is not the A/C.

No codes from keydance to start with.

Pulled the AC relay, no difference. Then I got 2 codes
First was "battery disconnected in last 50 starts"
The other was "AC relay short or open circuit"
Put relay back and code went.

Pulled spark plugs and all looked good.

Managed to start car after a lot of trying but it runs rough and cuts off if you don't keep revs up.

I've ordered a load of stuff from RockAuto today for other repairs, so I got a new coil and cam poison sensor so hopefully one of them will cure it!

This evening i got my meter out and measured the coil.

primary coil 0.6ohms on both sides

secondary coils about 11.8Kohm on both

So the coil seems to be ok ... what to test next?

still no codes

for a miracle

sounds like a valve train issue to me, whether it be cam/crank sensor or valve stuck open...
my head is toast, and after i changed the timing belt with my fingers crossed, it would barely hold an idle, noticeable popping from the intake, and absolutely no low end when forcing it to wobble down the road...
and im not too sure about neons a/c as mine has never had a/c.. but there should be a switch, other than the relay, that is under the hood and controls whether the clutch (iirc) kicks on or off. this should be located on the hard line somewhere on the high side.

The high side switch only turns the compressor off if the pressure is too high. It would not make it run otherwise. It's electrical contact is is normally closed. The other switch, if the freon level is too low, is also normally closed. Possibly the HVAC defrost was on, and it was frosted up from that. The A/C compressor does cycle with the defrost on...


Other than valve timing, The only thing that would cause popping from the exhaust, if it is at the manifold, may be a cracked manifold/header, or out the tail pipe would be a burnt/open valve.

I know the cast iron Manifolds have/can crack, causing all sorts of issues with the o2 sensor getting an enhanced amount of oxygen. But being an R/T you should have the shorty header. I have not heard of any issues with them, but it is not impossible. The gasket between the header and the down pipe could be another possibility, considering the o2 is in the down pipe, and not the header.

occasional demons wrote:Other than valve timing, The only thing that would cause popping from the exhaust, if it is at the manifold, may be a cracked manifold/header, or out the tail pipe would be a burnt/open valve.

I know the cast iron Manifolds have/can crack, causing all sorts of issues with the o2 sensor getting an enhanced amount of oxygen. But being an R/T you should have the shorty header. I have not heard of any issues with them, but it is not impossible. The gasket between the header and the down pipe could be another possibility, considering the o2 is in the down pipe, and not the header.

Thats would be annoying, i changed the Manifold gaskets only a little while ago when i did the timing belt (i took the manifold off the prevent damage when raising the engine)

from my limited experience with cars im gonna say it sounds like misfiring more than anything else

Well you did order a new coil. It is possible it is cracked internally somehow, and cross firing into the other side.

Or only breaking down under load?

Yes that is possible too. Depending on the wires you bought, 30,000 miles might be their lifespan also.

Oh the wires are unbranded but they look / feel good. I should megger them and check.

Is there any way to test the cam and crank sensors other than replace them?

The voltage output should change when a magnet is placed near the CPS, but that doesn't necessarily mean it is actually switching at speed. I would think if it was bad enough to make it run like crap, there would be a code. Eventually.

Damn I wish it would give me a code!

What are the chances of a dead PCM causing this?

I would say slim. Without checking the plug wires, compression etc, to rule out the basic stuff, it would be tough to lean towards the PCM.

occasional demons wrote:I would say slim. Without checking the plug wires, compression etc, to rule out the basic stuff, it would be tough to lean towards the PCM.

I Guess thats kinda good news.

a bit of an update, i dont know if its relevant.

when i try and start the engine normally, it just chugs over but wont start (you can hear occasional popping in the engine (i guess its where a cylinder fires occasionally)).

but if i put the gas pedal down to the floor and try and start it, it will start and rev up, runs like $#!T though and if you dont keep the pedal down the revs drop very low then it stalls ...

Could be a bad TPS. If it is shorted to WOT voltage, that may do it. It would be basically injecting max fuel, and with the throttle wide open, it is sort of matching air to fuel.

You could try pulling the connector off the TPS, and see if it runs (idles) better. You should definitely get a CEL then.

Possibly pull the MAP connector also.

occasional demons wrote:Could be a bad TPS. If it is shorted to WOT voltage, that may do it. It would be basically injecting max fuel, and with the throttle wide open, it is sort of matching air to fuel.

Thats an interesting idea ... actually i think my OBD2 reader has a TPS readout so ill try that too

How do the spark plugs look?

Donkeypuncher wrote:How do the spark plugs look?

They look absolutely fine, a little discoloured with normal usage but that aside, practically new

This may be a stooopid suggestion, but how are your battery terminals ?

I had a 'no-start' condition happen to me one time, when I went to a gas station - Refueled the car, and then it would not re-start.
It turns out that some Dufus ( read: me ) had not tightened the battery terminals sufficiently and they came loose.



Aside from this, I would suspect the coil and / or Spark Plug Wires.

I should mention that I once had a set of MoPar Performance plug wires, that tested O.K. with an ohmmeter - but one of them, was definitely going bad and 'shorting' internally.
It was 'snapping' during firing so loudly, that it sounded like valvetrain noise !! No exaggeration.

I replaced the spark plug wire set, and the (so-called) "valvetrain noise" went away.


- Nick

NickKo wrote:This may be a stooopid suggestion, but how are your battery terminals ?

They're fine, nice and clean. Plus the battery is only like a year old.

NickKo wrote: Aside from this, I would suspect the coil and / or Spark Plug Wires.

I hope it is something this simple!

still no codes come up.

New coil should arrive Tuesday so i can rule that out

I've been doing some tests with my OBD2 monnitor

The TPS seems to respond normally to gas pedal movement.

It says :

MIL = On
DTC = None

Intake Manifold Absolute Pressure is 14.36 PSI and when engine stared goes down to about 7 PSI

Both oxygen sensors around 0.5v

Well I am not sure on your MAP scale, but it should go to vacuum when started. If it is 7 in hg at idle, then there may be your problem. you should have a higher number for a vacuum reading at idle. Something in the 15 to 20 in/hg range.

So possibly the MAP sensor is bad, not reading the vacuum side properly, or you have a vacuum leak/engine problem.

You may need an actual vacuum gauge to see if it is fluttering, or steady.
Check the scenarios at the bottom in this link:
http://www.secondchancegarage.com/public/186.cfm

occasional demons wrote:Well I am not sure on your MAP scale, but it should go to vacuum when started. If it is 7 in hg at idle, then there may be your problem. you should have a higher number for a vacuum reading at idle. Something in the 15 to 20 in/hg range.

Ok we tend to work in PSI or BAR.

So 14.36 PSI-A is Atmospheric pressure so approx 1 BAR-A

(apparently converts to about 29.5 In/Hg)

which is the reading when engine is off (as expected - atmospheric pressure)

When idling its 7 PSI-A which is about 0.5 BAR-A
(apparently convers to be 14.25 In/Hg)