Mileage vs Engine Temp

dharder · 06-11-2005, 07:23 AM

My '73 2.0L gets 35 miles to a gallon but runs a little hot. Could running lean cause the heat? Is this mileage too good? Timing is right-on. I've recently installed new rings and valves to take care of a smoking problem hoping the hot-running problem would cure itself as well but it didn't. What kind of mileage do others get?

AaronM · 06-11-2005, 07:54 AM

Define "hot". What temperature are you getting?

If you're just going by the non-numbered stock guage in the dash, don't. That stock guage is basically an idiot light. Unless it pegs out at max, it doesn't really tell you anything useful.

Aaron

dharder · 06-11-2005, 08:22 AM

I've got a center console with a small-red area temp guage from a '74 and, after an hour or so of driving, it will be right up against the red. You're right, I probably shouldn't be trusting the 30 plus year old analog gauge. Next time I go out, I'll take my infrared thermometer. I'm still wondering about the mileage, though.

Bleyseng · Bleyseng's Garage

I get around 28-29 on the highway which is what they got new.
What MPS and ECU you running?
Vacuum hoses new and tight with no vacuum leaks anywhere?

Geoff

dharder · 06-11-2005, 06:12 PM

No vacuum leaks. I assume the MPS and ECU are stock. I got the car, completely stock, with 90k miles.

AaronM · 06-11-2005, 08:10 PM

Quote:

Originally posted by dharder
I've got a center console with a small-red area temp guage from a '74 and, after an hour or so of driving, it will be right up against the red. You're right, I probably shouldn't be trusting the 30 plus year old analog gauge. Next time I go out, I'll take my infrared thermometer. I'm still wondering about the mileage, though.

I just had the dash guage in my old '76. It ran right up on the red mark all the time. Never smelled of overheating and the oil never looked burnt (checked it often).

I don't think it matters if it's the dash unit or the console unit, unless it's a numbered unit. Everyone seems to agree that they run in the upper quarter of the guage's range.

Bleyseng · Bleyseng's Garage

My 76 oil temp gauge was always in the middle when I was running stock stuff so you too might be running hot.

I run a 911 combo gauge now with oil temp and pressure. Oil temps are around 210 on the highway.

A 73 2.0l should be running a 037 MPS with the stock 73 ECU, any other numbered MPS and you are running too LEAN. You can burn up that motor if it gets too hot. What are your oil temps?
Add a CHT gauge to see how hot the heads are as you can get them too hot so the valve seats will fall outta the heads.

Geoff

dharder · 06-12-2005, 07:22 AM

The number on the side of my MPS is 028 100 043. I guess this means it's not stock. I've got another MPS floating around somewhere that supposedly came off another '73. I'll dig it up and see if it's the correct one.

Bleyseng · Bleyseng's Garage

you are definately running lean with that

dharder · 06-12-2005, 08:52 AM

Done deal. I found I had an 037 MPS in my box of misc junk and just installed it. I'm not too sure of the integrity of the unit as the seal on the adjustment screw was gone and it looked like someone has messed with it.

What did an 043 come off of?

Bleyseng · Bleyseng's Garage

The 043 MPS is off the 74-76 2.0L engines and to be used with their ECU's.
The 037 MPS is for the 73 2.0l only! You should have your 037 unit checked out as the MPS controls the A/F mix.

dharder · 06-12-2005, 10:56 AM

Checked out how? I can put a vacuum gauge on it when I get to work tomorrow. How do you identify a '73 ECU?

Bleyseng · Bleyseng's Garage

You should have a 037 (CU13X) ECU as that is stock. MPS should have a 270ohn ballast resistor on the 012 CHT also.

Vacuum gauge test it by pulling a 15hg vacuum on it for 5 mins. Should be no leak down.

It can be recalibrated to spec by Jeff Bowlsby or me or go to a dyno shop and do it your self. Read the bible :
http://members.rennlist.com/pbanders/manifold_pressure_sensor.htm

dharder · 06-14-2005, 07:43 PM

It may be my imagination but it seems that since I switched from the 043 to the 037 MPS my car seems to be running considerably cooler-like 25%. With the console gauge reading just below 2/3, the temp of the engine pan by the drain plug is 202 degrees F and the taco plate is around 220 degrees F.

I haven't given it the true test of driving several hours over hilly terrain but I'm hopeful. The performance isn't quite what it was but, oh well....

Bleyseng · Bleyseng's Garage

The preformance is off because someone changed the factory settings or the MPS is leaking so throttle response is bad. Does it hold a 15hg vacuum for 5 minutes?

dharder · 06-16-2005, 07:10 PM

Maybe the performance of my car isn't off as much as I thought. I just blew past an Audi A4 at over 80mph on a 10% grade on a long pass near where I live. The old dog can still bite. Still seems to be running about 25% cooler.

dharder · 06-19-2005, 11:44 AM

My 037 MPS leaks off in 5-10 minutes.

Bleyseng · Bleyseng's Garage

Still useable but what about the WOT plug/stop? Is it still there or how was it adjusted?

dharder · 06-20-2005, 05:55 PM

WOT plug/stop? Wide open throttle plug/stop? Not sure what you're talking about.

Bleyseng · Bleyseng's Garage

See the big screw laying there? That is the WOT stop/plug.

It must be adjusted so it just touches the diaphram to support it and set the Wide Open Throttle A/F mix. If its wrong the diaphram cracks in short order.

Geoff