Help w/ rough iddle (part 2)

Pepito opined in news:2004120507543916807%josephamadeusNSPAM@mindsp ringcom:


>>> Speed Density
>>>
>

> Can you guys explain more?

Speed density doesnt have a MAF, and you dont...IIRC, the 2.3 didnt use a MAF
till it used the DIS ignition system... around '91

So you have no codes, you've changed the FPR and runs rough on warmup yet
RPM's are normal...

Afraid, that means I'd be looking for a bad cylinder... meaning low
compression. YOu could have a burnt valve, cracked exhaust ports or broken
rings in one or more..

Does the engine use a lot of oil?

After a fairly long trip, let engine cool a little and pull the plugs, look
at insulators, you'll probably find one much dirtier than others.. note
colors/shades of deposits

On 2004-12-05 08:56:31 -0500, Backyard Mechanic > said:

> Pepito opined in news:2004120507543916807%josephamadeusNSPAM@mindsp ringcom:
>
>
>>>> Speed Density
>>>>
>>
>
>> Can you guys explain more?
>
> Speed density doesnt have a MAF, and you dont...IIRC, the 2.3 didnt use
> a MAF till it used the DIS ignition system... around '91
>
> So you have no codes, you've changed the FPR and runs rough on warmup
> yet RPM's are normal...
>
> Afraid, that means I'd be looking for a bad cylinder... meaning low
> compression. YOu could have a burnt valve, cracked exhaust ports or
> broken rings in one or more..
>
> Does the engine use a lot of oil?
>
> After a fairly long trip, let engine cool a little and pull the plugs,
> look at insulators, you'll probably find one much dirtier than others..
> note colors/shades of deposits

It does burn oil and if it helps you come to a conclusion,,, when I
replaced the air filter I noticed a 1 or 2 inches wide yellowish stain
that smelled like engine oil in the part of the filter where it filters
vaccum coming from 2 small plastic hoses, (i hope you get the picture)

I haven't seen any weird looking smoke coming from the exaust, just gas
smell from time to time, when I replaced the plugs they looked pretty
normal, only gray deposits in the tip.

--
88' Mustang LX Convertible 2.3L

Pepito opined

>> Afraid, that means I'd be looking for a bad cylinder... meaning low
>> compression. YOu could have a burnt valve, cracked exhaust ports or
>> broken rings in one or more..
>>
>> Does the engine use a lot of oil?
>>
>> After a fairly long trip, let engine cool a little and pull the plugs,
>> look at insulators, you'll probably find one much dirtier than others..
>> note colors/shades of deposits
>
> It does burn oil and if it helps you come to a conclusion,,, when I
> replaced the air filter I noticed a 1 or 2 inches wide yellowish stain
> that smelled like engine oil in the part of the filter where it filters
> vaccum coming from 2 small plastic hoses, (i hope you get the picture)
>
> I haven't seen any weird looking smoke coming from the exaust, just gas
> smell from time to time, when I replaced the plugs they looked pretty
> normal, only gray deposits in the tip.
>

Uh-oh... have you been losing coolant?

Check the dipstick and oil filler for any sign of yellow-brownish deposits,
small moisture droplets, etc.

Also check the exhaust for "puffing".. and with engine idling best as it can,
hold a piece of light paper over the open oil filler, it shoudl suck down,
not "flap".

if it's puffin OUT of the filler you have bad rings .. or worse.

On 2004-12-06 22:52:25 -0500, Backyard Mechanic > said:

> Pepito opined
>>> Afraid, that means I'd be looking for a bad cylinder... meaning low
>>> compression. YOu could have a burnt valve, cracked exhaust ports or
>>> broken rings in one or more..
>>>
>>> Does the engine use a lot of oil?
>>>
>>> After a fairly long trip, let engine cool a little and pull the plugs,
>>> look at insulators, you'll probably find one much dirtier than others..
>>> note colors/shades of deposits
>>
>> It does burn oil and if it helps you come to a conclusion,,, when I
>> replaced the air filter I noticed a 1 or 2 inches wide yellowish stain
>> that smelled like engine oil in the part of the filter where it filters
>> vaccum coming from 2 small plastic hoses, (i hope you get the picture)
>>
>> I haven't seen any weird looking smoke coming from the exaust, just gas
>> smell from time to time, when I replaced the plugs they looked pretty
>> normal, only gray deposits in the tip.
>>
>
> Uh-oh... have you been losing coolant?
>
> Check the dipstick and oil filler for any sign of yellow-brownish
> deposits, small moisture droplets, etc.
>
> Also check the exhaust for "puffing".. and with engine idling best as
> it can, hold a piece of light paper over the open oil filler, it shoudl
> suck down, not "flap".
>
> if it's puffin OUT of the filler you have bad rings .. or worse.

The oil looks crystal clear, no coolant lose, I replaced the water pump
around 4 months ago. Never had coolant mixing with the oil or any
abnormal smoke from the exaust besides the gas smell thing.