Bad idle when warmed up

87CandyBlueT

87CandyBlueT

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Feb 8, 2006
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I only read through the first 5 or 6 posts. Any how I had this problem(engine shaking idling rough, sputtering etc. and it got worse over time where it would eventually stall after a minute or 2 of running. Mine ended up being a very loose ground strap. Fixed all my idle problems, sputtering and engine shaking. So check all of your grounds, mine was the strap on the intake manifold.(between where the upper and lower plenums meet)


Also I had the periodic code 31 for quite awhile, eventually I got a code 24 and 31 permanently and it ran very rough. So you should be picking up an extra set of electronics. Whatever you do, DO NOT TRY AND CLEAN THE AFM.

GL hope you get her fixed.
 
B

Back2Basics

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Dec 30, 2005
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Milwaukee, WI
Good advice. I noticed and had planned on upgrading my grounds next time I work on my car. I dont think mine are loose, but they are really rusted and corroded looking.

I hoping either that, a new water temp sensor or a new temp sensor connecting plug will fix my problem. I know I made another post, but nobody is responding so if someone thats reading this, and has a second or two, could you run out and check the part number that is on the water temp sensor connecting plug?? I'd really really appreciate it!!
 
B

Back2Basics

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Dec 30, 2005
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Milwaukee, WI
no, now im actually not getting any codes. I tested/messed around/adjusted a bunch of electronic parts just to see what it would do and Im not throwing any codes anymore, but my problem is still there.

at one point I did have a 51. I'll be able to check again this weekend to make sure. it really was bad last weekend because I finally got the car all running again after adjusting all that stuff and then all of a sudden I'm getting smoke coming from behind the dash. It ended up being coolant leaking out of the hard pipe at the back of the dash. The smoke was coming right from where that hard pipe exits the through the firewall on the passenger side.
 
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thevork

thevork

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Apr 28, 2005
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Well, today I took the iscv completely off. Cleaned everything and installed a new gasket. Also cleaned the boost check valve that was inside the manifold.
I rechecked the continuity of the iscv according to the tsrm and it turned out that it's all good. When I tried to check the movement of the valve by putting power to it and grounding s1,s2,s3,s4 (in that order, according to tsrm), the pintle only moved a very very small amount. If I looked very very well I just could see it move. So it barely moves. Is that normal?
Also: When I take the plug off while the engine is running, the rough running doesn't change. Actually nothing changes. there is no differense wheter I have it connected or not. Isn't that weird?


I also went ahead and checked and set the TPS according to the tsrm and checked for vacuum leaks AGAIN! Nothing seems to help.

Anyway I will also check the grounds. thank you for the hint.
And I don't know if it means anything, but sometimes during the sputtering and hasitation I can hear some kind of weird ticking noise. It's not regular and is a mixture of metal to metal and a really big spark going to metal. The sound is heard the best under the intake manifold. But maybe that's a really different problem.

@Dark006:
I also redid all the wiring going to the thermostat housing and the afm.
While I was at it I also redid the wiring going to the coil pack(s). Didn't help me but it's a good thing to do, even if it's just to make sure that a loose wire isn't really your problem. :)
 
B

Back2Basics

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Dec 30, 2005
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Milwaukee, WI
I'm going to redo the coil pack and battery grounds next. When you say you rewired the wires going to the thermostat housing and the AFM what exactly do you mean? Did you cut them and just attach wires to new connectors for each of the sensors? Can you take the wires out of the connectors somehow and reattach them more securely?
 
thevork

thevork

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Apr 28, 2005
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Well, I cut the wires from where I measured constant resistance (so I could be sure there was no faulty wire) and from there I attached the new wires. (otherwise I should've taken the whole wire out of the wiring loom)
I replaced about 30cm (as seen from the connector) from every wire because they were all very very bad.

Also, some of the plastic from the connector had to be cut where the wires were going in to the connector to get enough wire length from the wire in the connector to attach them securely.

For some other wires I just replaced the whole connector by other home-made connectors (the ones electricians use, those with the pvc sleeves to go over them. don't know what they're called).

If anything is unclear I can take pictures for you. :)
 
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Back2Basics

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Dec 30, 2005
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Milwaukee, WI
are they male/female spade connectors? and this is how you secured them to the connector plugs? if you could take some pictures that would help a lot! what year is your car? if its a pre89 could you take a look and see what the part number is on the ecu temp sensor? i have no numbers on my plug at all.
 
thevork

thevork

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Apr 28, 2005
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The batteries of my camera are currently charging. I'll take pictures as soon as I can. :) Everything is taped up but I hope it will be of use for you.

To secure the wire-to-wire and wire-to-connector I soldered everything together. That's the only way to get a good, constant and long-lasting connection.
The spade connectors themselves are a tight fit onto the male sensor part so no soldering is necessary. Just make sure that you tape it together

And I just used the female spade connectors because the male part is actually the part that is on the sensor.

Hope this makes sense... Will post pictures asap.
 
B

Back2Basics

Regular
Dec 30, 2005
317
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Milwaukee, WI
I think I got it. I take it you had to use REALLY small female spade connectors then for the ecu coolant temp and cold start injector sensors since the male connectors in the plug are quite small?
 
thevork

thevork

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Apr 28, 2005
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okay, little update about my own little problem:

Today after starting the car dies immediately. tried 3 or 4 times and every time the same. got sick of starting so i popped the hood and disconnected the icsv.
after that the car started and did not die on me anymore however the rpm varied between 700 and 1600rpm.

So when I got home I took my old icsv and hooked it up with icsv still out, and it moves when starting the car and when stopping it. but it does not move an inch when the car idles. not even when it idles bad or rough so it does not try to correct the air flow rate (at least that's my perception)

So what does this tell me/us ?
:)
 
jetjock

jetjock

creepy-ass cracka
Jul 11, 2005
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It tells me you're likely barking up the wrong tree. Be sure you have a code 51 with the throttle cracked and no code when it's closed. Why are you screwing with the ISC valve so much anyway? From what I've read you don't have an idle speed problem. You have an idle quality problem. Different things with different causes. That the idle varied with the ISCV disconnected is a sign of a mixture issue. Main ECU grounds are at the rear of the intake manifold. I seriously doubt they're the problem though.
 
thevork

thevork

ShoarmaTeam Member
Apr 28, 2005
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Okay this is new for me. :) Most topics about bad idling give info about checking things like TPS, AFM and ICSV. The first two are not the problem because I've swapped them for other parts that came off of a running supra. Therefore it leaves me with the ICSV.

Other topics, and my own mechanic who also owns a supra, tell me to check the wiring grounds, especially since we've installed a remote door lock/unlock device. We got a new 12v lead from the battery to it, and maybe there might be a problem there.
We also installed a new walbro fuel pump and I did the 12v mod. (checked at the pump and it's really getting 12v)

I get no error codes whatsoever. :(
 
Nick M

Nick M

Black Rifles Matter
Sep 9, 2005
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No error codes means the sensor and circuit are within parameters. I doen't mean it is working right. But that is one of the first things to check.
 
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