Drug another one home...

[SoCalMonty]

FYI - I have been running this for 40,000+ miles without a hiccup. It works great and according to my research is basically the exact same stuff that is in the Mitsubishi bottle. I also have 45,000 on it in Miss Skimakrart's Subaru.

Ditto. I've used the stuff for a while. Also have it in a couple Volvos. For high performance applications, though, it's Royal Purple or Amsoil Racing.

 

[SoCalMonty]

Sean,

How long have you been running the Castrol fluid? If you haven't already, a quick transmission fluid analysis might be a good idea to confirm all's well since it's not uncommon for problems associated with the wrong lube to take some time before they manifest themselves.

I know from other's experience on 4x4wire that Mobil 1 was claiming to work for the Mitsu's transmissions in much the same way. But after a while the owner discovered that it was in fact not working properly and it had caused excessive wear on his transmission. He only discovered this after performing an oil analysis several times over the life of the fluid. It showed excessive wear (metal particles in fluid) which cause some severe problems that ultimately resulted in a failed transmission.

Mobil-1 is NOT spec'd for Diamond SPIII: http://www.mobiloil.com/USA-English/MotorOil/Other_Products/Mobil_1_Synthetic_ATF.aspx

The Castrol I linked above is: http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9012226&contentId=7028224

For someone sophisticated enough to send out multiple fluid samples for analysis (on a 19 year old car), I'm surprised they didn't bother reading the label first! Would have saved them a lot of trouble.

 

[KarmannMarco]

Well , I bought a MAP sensor hoping it would fix the problem but it hasn't.
According to the code website P1400 can only be a Map sensor so now I need to figure out whether the sensor I got is faulty or if there's more to it.
I checked all the vacuum lines in and around the intake manifold for leaks but they all seem fine. They are dry and old looking but none of them have any cracks.
Regardless I will replace them for a piece of mind.
The EGR valve looks like it's seen better days. The bolts on it are covered in surface rust. Is there a way to check to see if it works ? At no point do I feel any vacuum into it or out of it when I pull the vacuum tube off it.

The truck does run good when warm. When its 50 or less outside when I start it , it dies right away unless I hold the gas at 1000+ RPM for about 15 seconds. After that It will hold an idle. On warmer days it will hold an idle right away but it fluctuated between 600-900 RPM in a pattern. At any driving speeds the truck drives great.

I do not want to rule out the plugs/wires but the code my truck is sending is intake manifold related and there's no missfire code so I will save this one for last.

 

[mapper]

Sorry, I did not re-read thread and just saw the last post so maybe I'm being redundant. Maybe MAP sensor is fine but MAP sensor readings are out of range and you have a leak into the intake. Seems the most obvious and that's where I always like to start. It would explain the temperature based issues as material expansion helps temporarily "seal" the leak. Check that intake carefully for any possible leaks.

Edit: As a matter of fact...I'd consider just pulling the upper plenum and giving it new plugs and upper intake plenum gasket. Takes a little time but you'll get new plugs...which couldn't hurt...in the process.

Edit #2: Or start by simply checking torque on upper plenum bolts. There are something like 7 of them and the torque spec is pretty low. I could easily see that one/all may have worked loose a bit and are causing a small amount of "un-metered" air into the motor.

 

[KarmannMarco]

Thanks for the advice Mapper.
I'm going to go over the whole intake and replace all the hoses.
In a week or two I will be doing a timing belt job so I'll do the plugs and wires at the same time. If it's not fixed by then it will rule out several possible causes.

 

[KarmannMarco]

Just Ordered for the 96 SR:

Dayco Timing belt kit ( includes water pump , belt , tensioner , idler , cam seals , crank seal )
All accessory belts
PCV Valve
Thermostat
Thermostat housing seals
NGK plugs and wires
New crank bolt and bolt washer

Am I missing anything ?

 

[mapper]

Off the top of my head...Valve cover gaskets, intake manifold gaskets and spark plug tube seals (they get flattened out and the plug holes fill with oily too).

Edit: not sure if the DOHC has the plug tube seals but I'm guessing it does. Also check the information on the butterfly valve issues (that is DOHC specific) as once your that deep it's a perfect time to make any changes/updates to that assembly as you deem necessary.

 

[KarmannMarco]

Thanks for the heads up Mapper.
Got that ordered now.
Not looking forward to a LONG day of maintenance....however cant wait till its all done.