Stalling Issue

[rvaughn]

Alright guys and gals here is the short and skinny on what I am experiencing. All my mods are current in my profile.

Background:
I installed three new gauges this weekend to replace/accompany my existing boost gauge and my aem wideband. I installed an electric boost gauge, oil pressure gauge, and an oil temp gauge. I utilized a prosport oil filter sandwich plate for the oil pressure and oil temp gauge. A new oil filter was installed and oil toped off during the install as the oil had just recently been changed. The gauges themselves seem to be working well, the only difference I notice is the electric boost gauge is reading different then my previous mechanical boost gauge in regard to vaccum, peak boost is the same. The old gauge read 16 vac while the new gauge is reading 19 vac. I am not super concerned but it does indicate that a vac leak is unlikely in my opinion.

The Issue:
The car starts fine in warm and cold conditions with no noticable change in behavior from pre-gauge install. I have noticed with the colder weather one or more of my belts is squeaking when cold, even when driving around town, the belt will sometimes squeak. It drives fine and pulls the same as it had. The issue comes when letting the rpms drop via holding the clutch in long enough for them to drop to idling speeds (always 750 rpm previous to issue) or from taking it outta gear to coast. When the car drops to what should be idling speed while coasting it actually drops idle down to ~250 rpm and dies/almost dies or recovers and sits at ~600 rpm. The new oil pressure gauge does indicate that the oil pressure is low (~9 psi) when the rpm bounces down below 750. I replaced the ISC last year but am considering it suspect at this point.

Attempted Resolution:
1)I have removed the boost line from the TB and placed a vaccum cap over the source and driven the car, no change.
2)I have verified that all TB common vaccum leaks are not to blame. I did not and will not adjust the BISS screw, the car will go to a professional before I touch it.
3)I have confirmed that the motor has enough oil.
4)I have checked ignition wires to be ensure tightness of connection.
5)I have verified the fuel pressure (to check for a vaccum leak).
6)I let the car sit over night and reapproached with no resolution.

Theories:
I would like some input here as I am running out of ideas. I still have a few options including; removal of the sandwich plate in an attempt to rule it out, tightening of squeaking belts, and an oil change which are both purely last ditch efforts.

Any insights you might have would be greatly appreciated.

 

[EvoInside]

Alright guys and gals here is the short and skinny on what I am experiencing. All my mods are current in my profile.

Background:
I installed three new gauges this weekend to replace/accompany my existing boost gauge and my aem wideband. I installed an electric boost gauge, oil pressure gauge, and an oil temp gauge. I utilized a prosport oil filter sandwich plate for the oil pressure and oil temp gauge. A new oil filter was installed and oil toped off during the install as the oil had just recently been changed. The gauges themselves seem to be working well, the only difference I notice is the electric boost gauge is reading different then my previous mechanical boost gauge in regard to vaccum, peak boost is the same. The old gauge read 16 vac while the new gauge is reading 19 vac. I am not super concerned but it does indicate that a vac leak is unlikely in my opinion.

The Issue:
The car starts fine in warm and cold conditions with no noticable change in behavior from pre-gauge install. I have noticed with the colder weather one or more of my belts is squeaking when cold, even when driving around town, the belt will sometimes squeak. It drives fine and pulls the same as it had. The issue comes when letting the rpms drop via holding the clutch in long enough for them to drop to idling speeds (always 750 rpm previous to issue) or from taking it outta gear to coast. When the car drops to what should be idling speed while coasting it actually drops idle down to ~250 rpm and dies/almost dies or recovers and sits at ~600 rpm. The new oil pressure gauge does indicate that the oil pressure is low (~9 psi) when the rpm bounces down below 750. I replaced the ISC last year but am considering it suspect at this point.

Attempted Resolution:
1)I have removed the boost line from the TB and placed a vaccum cap over the source and driven the car, no change.
2)I have verified that all TB common vaccum leaks are not to blame. I did not and will not adjust the BISS screw, the car will go to a professional before I touch it.
3)I have confirmed that the motor has enough oil.
4)I have checked ignition wires to be ensure tightness of connection.
5)I have verified the fuel pressure (to check for a vaccum leak).
6)I let the car sit over night and reapproached with no resolution.

Theories:
I would like some input here as I am running out of ideas. I still have a few options including; removal of the sandwich plate in an attempt to rule it out, tightening of squeaking belts, and an oil change which are both purely last ditch efforts.

Any insights you might have would be greatly appreciated.

Since your vacuum is reading lower with the new boost gauge, hook up your old gauge to the same vacuum source just to double check. If the gauges are consistant at reading slightly different, you can most likely rule out any leak you might have created by swapping them.

Next I would remove the sandwich plate. Its weird that your oil pressure is that low, that could be due to the gauge's lag time on responding to the sudden rpm drop. But at 750rpms your pressure shouldnt be that low at the sandwich plate.

When the car starts to act up, unplug the ISC, if the car shuts off right away, you can suspect the ISC is working or at least sort-of working right. If unplugging it has no effect, then you have isolated your problem.

 

[rvaughn]

I have read that under normal conditions, ie the car being warm, you can assume 10 psi oil pressure per 1000 rpms, with a 10 psi minimum, is this incorrect?

 

[morelock]

I have read that under normal conditions, ie the car being warm, you can assume 10 psi oil pressure per 1000 rpms, with a 10 psi minium, is this incorrect?

so at 7k your ruining about 70 psi oil pressure.WTF

 

[rvaughn]

You make a decent point, I had not considered it at those levels. You will have to forgive the ignorance, I have been using the stock oil pressure gauge to monitor oil pressure until now and have little experience in that department! Note taken, so what would you expect warm idle oil pressure to be?

 

[morelock]

it depends i see over 100 during cold start up and about 25 at 1k idle

25 after car warms up.

 

[rvaughn]

Ok, well I know at startup, while in the warming idle stage the car sits at 65 psi oil pressure. It then drops down (slowly) to 10 psi oil pressure once the car is completely warm (at idle). Keep in mind I have my balance shafts, and doing more research I am finding that there are others sitting at 10 psi oil pressure during idle. Anyone else want to chime in to put my mind at ease or make me worry some more as far as the pressure at idle? Still looking for some more opinions and answers as far as potential issue! All answers this far are under investigation!

 

[rvaughn]

A little update, I removed the IAC today and verified that the coil resistances were within acceptable values, no issue there. I then ran a couple logs with dsm link that I need to look at a bit later, and increased the idle by 100 rpm. With the idle rpm set at 850 the car runs fine, Im assuming at this point that one of two things is happening.

1) I have a vacuum leak that I need to pin point. (Likely, but like I said I have looked at the 'normal' leaks I have found before on the car.)
2) The newly added sandwich plate has put strain on the oil pump somehow which as far as I know is original to the car and could be showing its age.

I find it hard to believe that the oil pump would only show signs of weakness at idle but I am kinda stumped as to what else to look for. I noted that when doing a quick, fully warmed up car, second gear pull my peak oil pressure was 90 psi, can anyone confirm decent peak oil pressure on a pull? I also talked with English Racing and they said 10 psi oil pressure at idle is normal. Any other thoughts as to how I can cure my issue, I don't like the idea of leaving my idle up but right now it is the only way to drive the car.

 

[97eclipseNT]

Did you take your throttle body off to look at it? I was having idle surge/ stalling problems. The front (intercooler side) of the throttle body looked clean but when I took it off the other side of it was disgusting. After thoroughly cleaning it out using pipe brushes to get into the small holes (ISC holes, BISS screw holes, etc.) it idles perfect now. Just another thing to try.