Hi guys. Sorry to be out of touch. I ended up in the coronary care unit for angioplasty and a stent in November. That kind of takes the wind out of you for awhile, but here I am again playing with cars.

When the weather got cold, my EFI turbo slant got to where it would not run well during warm up. It was very discouraging. One of the reasons I switched to EFI was to improve coldweather drivability! After playing with the computer warmup settings endlessly, with very little improvement, I noticed that the computer was registering higher temperatures during warmup than the gauge. The sender for the gauge was in the block and the sender for the computer was in the head. The computer was switching off warm up enrichments before the engine was really warm. I simply switched the two, and voila! The engine is MUCH better during warm up. The block sensor warms up more slowly than the head, and the computer sees a much more even, moderate raise in temperature, and thus keeps the warm up enrichments on longer. If you are considering EFI, use the drain plug for the coolant temp sender, not the head.

Did you use the batch FI or some other type system?

I was wondering where you were Mr Vader. Im glad to hear you are doing better. I too ended up with some cardiac things trashing my November. It must be something to do with 5 spd. EFI afficianados. I hope Lou is ok...

You observations on sensor placement are interesting. The drainplug location would be the last place the operating temps would be reached.....good for puter "warmup"

This week I did a whole tune on my TBI Sub using a scan tool called "Genesis". I was able to deal with quite a number of outstanding issues created by the relatively large cam and aftermarket intake. The tool is owned by the shop where we get fleet maintenence done. Its worth $3500 (I wont be getting one). It was informative to watch the relationship between sensor progress and open/closed loop operation in cold temps. I had a collector gasket leak that "fooled" the oxygen sensor and a "lazy" oxygen sensor. Both were easily spotted by the scan tool. I am scheduled for a dyno run in mid-jan. I am hoping for 300 RWHP and about 350ft/lb torque. Just the thing for trailer towing.

I can see that the scan tool will be an essential part of the slant TBI initial tune.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Where did you obtain a drain plug sensor?

My slant 6 is on an engine stand awaiting installation in my 63 Dart GT convertible. I used a later head that came from the factory with the additional sensor in the head for water temp.

So, this sensor location is less than ideal for cold weather operation?

I intend to add Electromotive's TEC3 to my slant 6. I wonder if its programmability with a notebook computer can compensate.

--Walt Jackson

Sandy, are you better? What kinda goings on there with you? Lou is fine, although he is in New Zeeland right now.

Walter, it all depends on how your computer warmups are divided. The Mega Squirt computer exits warm up enrichments at 160 degrees. That was too low a temperature for the slant head. The slant still wanted some enrichemnt at head temps of 195. At this point the gauge was still reading 150 at the lower water jacket drain plug location. The slant drain plug thread is the same, 3/8" npt as the standard GM (UGH ) coolant temp sender. I have found this an easy fix for the problem, and the temp there is a much better reference for the mixture needs than right behind the thermostat, which gets real hot fast, and then cools off again after the thermostat opens.

First of all, glad you are feeling better, 'vader. Secondly, I'm having the same issues with my MS and the coolant temp sensor in my 360. I posted a note on msefi.com to see if anybody else had the same problem, but no sensible responses yet.

What I think is the real problem is the default calibration for the GM temp sensor, which I am using also. Cold, the sensor will show almost 20* warmer than it actually is. Consequently, the enrichment gets shut off too soon with the same drivability issues you mention.

I have the sensor in the stock coolant temp sensor location in the TBI manifold, which is up front, near the thermostat. I have considered moving it, as you did, for the same reason.

Really, though, I think that is curing the symptom rather than the problem - which I will do if it comes to that. I would rather fix the sensor calibration though. The MAT sensor, which is the same part number, seems to work fine. I'll do some more research and keep you posted.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Im Ok Vader. I have a ventricular arrythmia problem. This requires an EPS study which has an 8 month waiting list. The Good news is I am in excellent health in every other way (I even managed some very limited snowboarding the other day) I just cant get my heart rate over about 110 BPM without getting into trouble. Seems I like to live my life at about 130BPM. They wouldn t let me drive at first but I fixed that PDQ.

Whats your heart story?

What program do you use to mess with the MS?
Are you running a closed loop/oxygen sensor setup?

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Gun pilot. Thanks for your feedback. I had about the same success posting on the MS board. Does your car run OK when warmed up? How did you determine that the GM sensor reading was off? Did you measure the water temp with a thermometer? I don;t recall thinking my 'realtime' display on the Megatune program readout was showing me cold temp. readings that were off from the cold coolant temp. I could be way off here as I did not actually measure the temp of the coolant when it was cold, and compare it to the 'realtime' diplay's temp reading, but the reading I was seeing seemd logical. I could buy a thermometer and check it now, as the temp of the coolant should be uniform throughout the jacket before you start it. I have followed the warm up temps as they progress since changing the location of the sensors, and the gauge sendor is now reading higher than the computer sensor, until it gets fully warmed up, and then they read about the same. The head shows about 195, and the water jacket shows 190 or so. I would not hesitate to fix your 360 with the sensor location switch if I were you. I have a 360 in another dart, with a thermoquad and stock aircleaner, and the cold start drivability is perfect, so it should be possible to get your computerized EFI version of it to do better.

Sandy, I had 95% blockage in the left coronary artery. When the heart rate got to 105, it felt like a brick was sitting on my chest. Everything seems cool now. I have perfect weight for my height, exercise regularly, don;t smoke, and am a vegitarian, so all you overweight, smoking, Big Mac lovers can laugh your fannies off now. My business partner has your problem. It is seldom, if ever, fatal but it scares him because his heart beat gets goofed under certain circustances. Are your symptoms like his?

Once it is warmed up, the thing runs awesome. It doesn't really run all that bad cold, but it's just impossible to get an accurate cold enrichment setting on it the way it is.

The way I determined the sensor was off was simply by walking outside on a 60-degree morning and noticing the CLT sensor reading was around 80 before start-up on a stone-cold engine. Not scientific I know but enough to tell me something's amiss. Plus, I have an accurate Autometer temp gauge installed, and it disagrees with the GM CLT sensor by a corresponding amount. The sensor for the autometer is in the stock temp sender location, opposite the CLT sensor, so they should be getting similar amounts of heat. The enrichment LED will go out (supposedly at 160 degerees) when the Autometer is hardly off the peg.

I am going to work with Easy Therm a bit, and try to get a better calibration of this sensor. The computer I was using to tune packed it in, so I'm a little behind, but I have a new one almost ready.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Im Not sure how this relates...but something here sounds familiar. On a non-slant EFI project I have going we cant seem to get the oxygen sensor(several new and know tried) to "read" correctly at the PCM. The resulting scanned BLM readings and O2 sensor voltages are way off resulting in lean mixtures below 2000rpm. Current thinking points toward a bad ground at the PCM.

Troubleshooting this stuff can be a tad frustrating/rewarding. A lot of non-linear thinking necessary. The scan tool does all the conventional thinking....leaving us with the rest.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Sandy, are you sure the sensor is getting hot enough? How far away is it from the head in the exhaust? An o2 sensor will not read properly if not hot enough. Try a heated o2 sensor.

One thing to try with warmup and/or variable climate problems is moving the MAT (air temp) sensor around too. I wouldn't be surprised if it doesn't adjust as well for climate if it's in the manifold vs. the air cleaner.

I bet the high reading CLT sensor is probably just a poorly calibrated sensor off the shelf, or a high resistance (bad contact) wire to it.

Sad to hear about Sandy's and Vader's heart issues. Keep 'em outta the red (or build back up) so we can enjoy you guys for a lot longer!

Lou Down Undah

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Home of Slant6-powered fun machines since 1988

I thought the same thing about the sensor so I returned it to NAPA and exchanged it. No change. But that's a good thought about the wire being bad. I'll put a meter between the sensor and ground, and compare it to the wire/ground at the relay board.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Check that. I'll actually test it all the way out to the pin on the DB37 that plugs into the MS. That way I'm looking at the whole thing from sensor to MS. If that checks out, I'll check the MS itself.

Thanks for the push, Lou. Grab one of those Hemi Slants while you're down there.

Check it again. I know the MS box is good, because it's fine on the Stim.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!

Checked it tonight. The resistance at the sensor was the same at the end of the DB37 tha plugs into the MS. So the wire is good. I'll look in the computer.

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It's a Slant thing. Even I don't understand.

1974 Duster, EFI /6 soon to be turbo...

Get that Monkay! Get that nasty thing!!