TR cold start

Hello
I have previously posted how my 1991 US TR runs really poorly (idles around 700 rpm, spits and sputters, missing throttle) when cold.

I know that they are not ever going to run perfect when they are cold. However, I stored it last Winter. It came out firing fantastic. Even in really warm weather.
It would fire up and run at around 1200rpm then slow down when it was cool. Sounded great, good throttle response and most importantly not embarrassing.

It recently got caught in a rain storm and returned to it's old ways.

I have done some research and dried out the cold start injectors connections, the 2 water temperature sensors and the third sensor on the side of the same housing. (At work now so don't have manual for exact name.)

Maybe a small improvement. The brown water temperature sensor has a small tear in the outer wire coating so I may shrink wrap that.

The manual also talks about the auxillary air valve being important in cold starts.

Can I clean these parts. Can I dissassemble the auxillary air valve safely without ruining it.
Is there something I'm missing.Is there moisture in the wires?

Brian I know you said it won't ever be good, even from the factory they said don't bother trying, but because it was better for a few months, I was hoping to make it that way permanently. Any input from you would be greatly appreciated.
Thanks. Brent.

 

(Responding to a PM in order to post pics)

Your post implies that warm-running is OK, but there are some tests that you should do here before going further IMO. Almost unfortunately, if the "E" part of a KE-Jet system is totally dead, the warm-running can still be OKish if the manual mixture screw is tweaked up (during warm-running) to compensate (although cold-running won't work correctly). Consequently, I would suggest that you first measure the voltage on the single output wire from each O2 sensor relative to ground (like the engine block) while at warm idle (while the single wire is still plugged in) -- the voltage should be slowly "wandering" between about 0.1V DC and 0.9V DC on both O2 sensors if warm-running (and the "E" part of KE-Jet) is really working OK.

If you pass that test (call that Test 0), make the three voltage measurements as shown in this jpeg to confirm/deny if the (many) events required for proper cold-running are occurring:
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If you don't have access to the US TR wiring diagram book 509/88, there is a schematic of the US TR KE-Jet system shown on page 74 in the '91 US TR OM. The way the system is supposed to work during cold-running (meaning after being shut-off overnight and before the coolant temp gets up to ~150 deg F) is:

The coolant thermoswitch M (or item 33 on page 74) is closed when cold, as is the oil thermoswitch (item 32 on page 74) unless really, really cold. This closes relay A ...006 (item 34 on page 74) in the black triangular box. This puts a ground signal on pin 16 of each injection ECU to "tell" the injection ECUs "hey, I'm cold, so increase the EHA current for a while to add richness and ignore the O2 sensor outputs (because they are cold and the air injection system is running)". When relay A is closed, this also activates the electrovalve D (item 36 on page 74) and the air pump clutch (item 37 on page 74) to turn "on" the air injection system. The "tests" in the jpeg are only looking at what is, or isn't, happening at electrovalve D, but it will confirm/deny if relay A is doing the right thing or not.

The ball is in your court for results to Tests 0, 1, 2, and 3

Here's a clearer shot of what the Electrovalve looks like:
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I should have included that there would certainly be no harm in removing your AAVs and checking that they do open somewhat when placed in the refrigerator, and close when placed in the oven -- but you'll be lucky if those are the problem

 

Steven,
"Hats off" to you, I must say !!! Such an increadibly valuable post !
I wish, I could meet with you to show you my Testarossa and hear your opinion about the car... Do you ever travel to Houston?

 

No, Houston isn't in my usual travel plans (although we did make a special trip last month to Rosenburg to rescue/adopt a couple of Shar Pei).
My original plan was to not know so much about my TR, but it didn't work out that way -- what a surprise .

 

Well, if you will be comming to Houston in the future, please let me know. I would really like to meet you in person and share a pint or two.

 

Thanks Steve. Just got back in town.
During our engine out 2 years ago, one of the outlets on the electrovalve was noticed to be broken. It appeared to have been glued previously. I epoxied it back in place and made what I believe to be the proper connections.
I will perform those tests. I will let you know the results.

It's just odd that it worked well up until it got rained on.

This is tremendous information. If you ever need veterinary information on the pets let me know. Thanks. Brent.

 

One more quick thing.
Does it matter which way the wires are connected.
I switched them around and it seemed to start up a littler better. Still idling a little rough but better than previously. Unsure if this is my hoping it's a simple fix.
Thanks. Brent.

 

What component?

 

Sorry Steve.
On the electrovalve. It's what I would call a double spade connector. Red wire and black/purple. Does it make a difference if you flip it around and attach it the opposite way.

I Performed the tests you reccomened but realized I did not do them properly.

I tested the red wire while running cold vs a ground and it was 14 volts.

But I tested the red wire against a ground when it was running hot and also got 14 volts.

I came back in and realized I have to test the red wire relative to the black/purple wire.

Any suggestions on ways to do this while they are still connected to the electrovalve?
Thanks. Brent.

 

I also forgot to mention that the colder it is, the better it starts.
If it's below freezing, everything seems to fire up well.
Thanks. Brent.

 

No, I think that's OK (i.e., the coil in the electrovalve is electrically isolated from everything else so no polarity to observe).

Right, you did test #1 OK (and passed), but you haven't yet done tests 2 and 3.

You can do it with them unplugged, but there is a chance you could get a false result (if the wiring/other connections have a particular kind of high resistance defect). Usually, you can only partially engage the spade connectors, so they are electrically connected, yet leave enough exposed so you can touch the meter leads to a bare area of the male spade (although I realize it is sort of a cramped area). Worst case, you would need to fabricate a couple of male spade -to- female spade jumpers with another wire "T'ed" off each to connect to the meter leads.

Could be that the motion of the shutters inside your AAVs have just "aged" so they aren't open as much a fresh ones would be when cold (re your comments about really cold temp being better). If you pass tests 2 and 3, that would be the next thing to look at -- IIRC, people have posted "typical" pictures looking inside their AAV when coming out of the fridge and/or freezer for comparison.

 

Hello again.
It wasen't that difficult to test. Just slipped the probes under the covering.
Results:
Test 2= 13.48 volts while running cold
Test 3= 0 volts while running warm/hot

Looks like it passed the tests if I'm reading it properly.

Looks like the next step is checking the AAV?

Let me know what you think, and if that is the next step, if you could point me in the direction of some info on taking them apart, that would be great. Worshop manual has some diagrams.
Thanks. Brent.