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All is well until '86 560sL is warm...

955 views 2 replies 2 participants last post by  pmac7488 
#1 ·
I've read and read and read...and nothing is *quite* what my situation is...

A bit about me:
26-year-old electrical engineer. I've always driven Toyotas (and fixed Toyotas)...exhaust systems, O2 sensors, distributor caps, rotors, wires, plugs, oil changes/filters, alternators...I've done some things and I feel like I'm vaguely-qualified for anything that this topic might call for me to do.

A bit about the car:

The car as approximately 131,000 miles on it. I say approximately because I reset the tripmeter while the car was moving once and the odometer has not worked since (August 23rd, 2013). When I originally purchased the car, I briefly read about what to look out for...original fenders, mis-matched paint, broken paint around screws...blah blah blah. I also read that the engine likes to kill itself if, specifically, select top timing chain guides fracture and cause interference issues between chain and sprocket. I have removed the valve covers and noted that the camshafts look correct (no lobes are appreciably warn) and I also know that the guides, at the moment, are original and not fractured.

When I first got the car, I replaced all brake hardware - calipers, pads, rotors, fluid...I figured, above all, it'll stop! I also replaced the spark plugs with the NGK plugs that all of these forums swear by - it ran fine afterwards. I've topped off the power steering, noted that engine coolant was full, and changed the oil WITH 10W-40 synthetic, and I also changed the mondo filter that this car has for the oil.

Aside from other little things like bulbs, a radio, and 6x9 speakers in the back, nothing else has been done.

The power antenna does not work anymore (shocker!) and the AC never has (the belt is physically not there on the compressor - I assume the compressor is bad). There is pressure in the lines, but I'm not sure if that is freon or hot air under pressure. Either way, it doesn't work.

Now, the issue...

When the car is cold - as in - has sat all day and has not been run - it takes one or two cranks to start. Usually, one crank is plenty. It starts up, overshoots to about 1,000 RPM, and then gradually settles around 600-650 RPM. Either way, it is generally steady at this RPM. The oil pressure gauge is pegged at "3" and the economy gauge, in park or neutral, sits happily to the left.

When I put the car in gear - forward or reverse - the economy gauge moves towards the right, maybe 1/10th of the total span of the gauge. I pull the car out of the space and I drive it for 10 - 15 minutes in warm (75-80*F) weather.

After this warm-up phase, the temperature gauge sits happily(?) at 80. When I then slow the car down to stop at a light, stop sign, or in traffic, the RPMs go down further than the original 600-650 RPM, but not much lower. The engine sounds as though it is idling weaker and the economy gauge is much further to the right than in the original cold state - I'd say between 1/8th and 1/4th of the span of the gauge as compared to the 1/10th (which I still think is too high) when cold. At the same time, the oil pressure gauge reads "2", sometimes about "1.5" if the car has been run for a half hour or more. In this state, in very hot (85-90*F) weather, the car may continue to idle, or sometimes, it gives in and stalls.

Whether the car stalls or I physically shut the car off, it is very difficult to get running again. Several engine turn-overs is the usual procedure, followed by swift gas pedal action to keep the idle 1,000 RPM. At this point, I'm shifting into reverse or drive while holding the brake and gas at the same time. Not a good situation and not a safe situation, particularly in reverse and in a parking lot. I then begin driving to wherever I'm going - carefully making sure the RPMs are above 700 RPM by whatever means are necessary. Keeping the RPMs up in this manner keeps the oil pressure gauge at or near "3", which is where the car runs happily and smoothly.

A few forums with members posting related problems cited a vacuum leak check was in order. While parked and with hood open, I carefully pulsed a can of starting ether all around every vacuum line I could visibly see. The only difference in engine sound was observed when a burst was sprayed directly into the intake. The engine surged a moment and then was back to normal idle.

I also cleaned what little guck was in and around the intake (under the air filter housing, venturi might be the word?) This did not help either.

Between my buying the car and driving...it might sit for a day to a week. It sat through the winter last year outside. I started it up and let it warm itself for 10 - 15 minutes at least once a week to keep it running "well".

That's pretty much all I've got so far. If anyone has had THIS specific problem and knows what maintenance needs performed to make this car run smoother as it warms up, I would greatly appreciate your experience and advice. :)

Thank you!
Paul
 
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