1G Optimal operating temp. without a logger?

[93AWDDSM]

hey guys, I did my HG recently and was having issues with pushing coolant and over heating a little. I fixed my radiator leaks, all hoses and new radiator cap/t stat (180 degree). I also put my stock heat shield back on which seems to help quite a bit.

It now runs good but I have a question, the temp gauge now sits a little lower towards colder and my idle is around 1300-1500 @ lights/stops. Could this be because of the T stat's lower degree?

there's a pic attached.

EDIT: I forgot to mention. even when I was doing some sprinted driving through most gears, the temp raised a hair and then went back to this position. Even after hard runs it wasn't budging, are we in the clear?

****compression test was done on 2/19 and results = 4/160 psi, 3/155 psi, 2/160 psi, 1/160 psi

 

[gst-turbo]

You should get a temp guage there only like 30 doller at the parts store it read numbers and will telll you the temp more accurate.

 

[tmoney20g]

for best results, replace both temp sensors if you have no idea how old they are. the 1-wire goes to the dash needle gauge, the 2-wire goes to the ecu.

for even better results, tap a line off the 1-wire gauge to an actual aftermarket gauge with numbers on it, which may also come with the probe you can use to replace the 1-wire temp sensor, which i believe is 1/8 npt.

 

[300K_1G]

I doubt the high idle has anything to do with temperature. Try adjusting idle back down to normal and see if the temperature climbs.

 

[o0GuitarKid0o]

Do your fans come on?
Check your thermal sensor for the fans there's 2 on a 1g

But Get that idle under control it definitely is not helping with your temps
Btw you could be maxing out you isc motor and that's a good way to burn it out

Make sure you ground out the diagnoses port

And ground out that connector on the fire wall

Don't just adjust the biss with out doing that^^^

VFAQ has a good guide,
I'm sure there's a guide on tuners also

Does the coolent gauge get higher than that picture you posted ?

 

[93AWDDSM]

Okay, backstory. Car overheated end of December 2015. Sat for a month while head was getting worked on/retrieving parts. Once I put it back together I noticed the radiator had a leak from the bottom where the (2) prongs set on the bottom, thought no biggie. At about 500 miles after head work/HG I noticed the temperature starting to climb upwards to the right side of the "P" on the temp gauge.

When I saw it start to climb I would hit my defrost (fan turns on) on and run it till it got back to middle of "E and M" on the dash cluster. I assumed air was being sucked in from the radiator leaking somehow and a few days later I noticed I had the bubbling in my overflow tank after NORMAL driving/-vacuum. I replaced the following: upper radiator hose, T stat(180 degree), new radiator cap, still bubbled and "overheated/warmed up past the "P" I just replaced the leaky radiator two days ago and added the stock heat shield to the 2g manifold I have on, and so far I have no coolant leaks, I'm not burning coolant or mixing it. compression test was good across all 4 cylinders and now its running as you saw in the picture.

I'm looking into replacing the Temp. gauge sensor and the CTS just because. I'm also building a BLT'er tomorrow!

Do your fans come on?

Does the coolent gauge get higher than that picture you posted ?

Fan turns on/off and since the past two days. I haven't noticed the temp gauge get any higher than that even after some 5-7K sprints but is it possible that it's stuck in open loop causing high idle and rich because of the 180* t stat?

 

[tmoney20g]

t-stat won't make it rich, just opens the entire water cooling loop earlier so initial warm-up takes a smidge longer.

since you replaced the head, how about base ignition timing ?

check the t-stat cap with the car cold, make sure its full in there.

 

[93AWDDSM]

since you replaced the head, how about base ignition timing ?
check the t-stat cap with the car cold, make sure its full in there.

BLT and Timing light/base ign. timing are tomorrows checklist. Yes, I've checked the T-stat cap with it cold and it's still full. I'm not so worried about the idle, more if the temperature gauge is actually reading correct. It seems like it because I let car get to operating temperature and the fan came on ran for a while then turned off. I think it reached it's peak hotness and then was cooled down.

 

[steve]

The fans are activated by the thermo-switch in the bottom of the radiator. On a 1G the ECU has no control over the fans but the ECU does get the engine coolant temp as an input it uses for various fueling decisions. The connector to the ECT sensor is well known for the wires breaking which usually causes hard starting problems when it's warm out.

The FSM has resistance measurements for the sensor at various temps and you can measure them at the ECU pins to check both the sensor and wiring. Since the gauge is off a bit I'd get out the multimeter and verify that the ECT and gauge sensors are accurate. The idle speed is likely caused by other issues.

A datalogger is always a good idea if your going to be keeping the car to diagnose these sorts of issues. It will tell you what the ECU thinks the temp, and where the ISC is stepped to which helps debugging the idle issues.

 

[o0GuitarKid0o]

Fan turns on/off and since the past two days. I haven't noticed the temp gauge get any higher than that even after some 5-7K sprints but is it possible that it's stuck in open loop causing high idle and rich because of the 180* t stat?

There's an "idle position switch " located on the throttle body this may be your problem once you let off off the gas it's triggered.
it may just need a simple adjustment

When mine went bad I had high idle up to 1600 rpms

You really need a logger mine tells me pretty much everything

 

[93AWDDSM]

The fans are activated by the thermo-switch in the bottom of the radiator. On a 1G the ECU has no control over the fans but the ECU does get the engine coolant temp as an input it uses for various fueling decisions. The connector to the ECT sensor is well known for the wires breaking which usually causes hard starting problems when it's warm out.

The FSM has resistance measurements for the sensor at various temps and you can measure them at the ECU pins to check both the sensor and wiring. Since the gauge is off a bit I'd get out the multimeter and verify that the ECT and gauge sensors are accurate. The idle speed is likely caused by other issues.

A datalogger is always a good idea if your going to be keeping the car to diagnose these sorts of issues. It will tell you what the ECU thinks the temp, and where the ISC is stepped to which helps debugging the idle issues.

OK, I'll pick up a multi meter tomorrow and try to test those. Should I run the car hot then test the CTS? it says 176* should be 0.3 Ohms. How will I know the car is at or above 176* for correct testing without removing and testing in a pot of hot water.

 

[93AWDDSM]

There's an "idle position switch " this may be your problem once you let off off the gas it's triggered

When mine went bad I had high idle up to 1600 rpms

You really need a logger mine tells me pretty much everything

Idle switch is set for continuity and is working. I'm 48% sure that my whole tank of radiator was leaking/sucking air bubbles as well as the bottom drip drip was causing my temperatures to rise (not to the red) but past the P and then back to normal-ish. It wouldn't PEG overheating/red though.

and yes, a logger is definitely what I'll be getting again soon.

Also, I forgot to mention the weather in my area is currently fluctuating around 32-50 degrees throughout the day

 

[93AWDDSM]

Update: got a timing light, it's now set at 5* BTDC. I also tested the IPS switch with the multimeter and it didn't give me any continuity. Also, there was no difference in idle speed when the green wire spade was unplugged. Time for a new one.

As for the overheating I'm still tinkering for that stuff.

 

[steve]

Make sure that the TB is still grounded. Over the years the grounding strap from the throttle elbow to the top of the throttle body seem to go AWOL which leads to the IPS not working and the ECU not knowing to manage the idle speed.

 

[93AWDDSM]

Do you have a quick picture on hand? I only see the ground for the throttle cable?

 

[steve]

Do you have a quick picture on hand? I only see the ground for the throttle cable?

http://www.dsmtuners.com/threads/new-problem.404895/#post-152612174

 

[93AWDDSM]

Lol. Thanks, but that part is long gone. I have a vrspeed fmic kit. What's the best way to get it set up correctly?

Thank you.

 

[steve]

Lol. Thanks, but that part is long gone. What's the best way to get it set up correctly?

You now know what it is and what's it's for, what's the best way on your car to ground the TB so that your IPS will work?

If you still have the screw that goes on the TB top (or have one with the right threads), Id' run a wire from it to the Intake Manifold ground and test your IPS again.

 

[93AWDDSM]

Basically like this

 

[steve]

Yes, that will work.
Note that car still has the factory TB ground.

 

[93AWDDSM]

I got it to ground, when I went to adjust the IPS it started making the car idle surge, unless I backed it off. Could this possibly be a bad IPS switch?

 

[steve]

Nope, not a bad switch. Now that it's working you need to fix your idle surging cause by the engine idling too high when the throttle is closed. The stock ECU wants to maintain a 750 +- 50 RPM and if it's higher than about 1k the ECU cuts off the injectors until the RPMs drop.

That could be a bad ISC, FIAV not closing, BISS adjustment, air leaks, throttle blade not closing, etc.

 

[93AWDDSM]

Nope, not a bad switch. Now that it's working you need to fix your idle surging cause by the engine idling too high when the throttle is closed. The stock ECU wants to maintain a 750 +- 50 RPM and if it's higher than about 1k the ECU cuts off the injectors until the RPMs drop.

That could be a bad ISC, FIAV not closing, air leaks, throttle blade not closing, etc.

Thanks I'll be looking into this stuff shortly.

 

[o0GuitarKid0o]

http://www.vfaq.com/mods/BISS-1G.html

Make sure you adjust the biss properly ^use this guide

Keep this in mind
it's possible your over adjusting the ips ,
If you screwed it in to tight you may be causeing the throttle plate to be open slightly.

If so than This will completely screw up your idle (I no first hand , had to replace my ips twice due to it failing when HOT)

You want to just barely make continuity and than do like a 1/16 turn in

My car seems to idle nice around 850-900 but every cars different

 

[steve]

Forgot the BISS, edited in case someone looks in the future. Thanks!