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Discussion Starter · #1 ·
I want to throw this problem out there. Hopefully there are some experts here who can help.

This is the same vehicle with the fuel pulse damper problem. We've had two mechanics say that the reason the engine keeps dying at idle, is the throttle body. Neither one have offered up any evidence as to the specific problem with it. I would have ask, but they were talking in the dialect and I didn't understand. The second mechanic was here at our house yesterday with the buyer. He looks at it, and says it needs a throttle body, duhhh. Car won't run, were waiting on the pulse damper to arrive. So obviously I am trying see how he arrived at his diagnoses!

This morning I went over and removed the inlet air supply hose, and looked into the housing at the butterfly valve. I could see no problems, cracks, or any missing parts on any of it inside or out. There is however about 1/16in of play where the shaft goes thru the housing, this is a side to side play on the accelerator cable side. I also found a hose about to come off some sort of component below the throttle body, which it is mounted to. See attached photos, about 5 of them.

This thing cost P2850...equivalent to $533.00 US dollars, So you can see why I am skeptical. Mechanics here have a bad habit of changing out parts that are not bad, and or giving a bad diagnoses. We don't want to be like the guy who replaced his three times, and still has the same issue. I was also thinking maybe this pulse damper problem could also be a reason why the engine has been dying at idle...

Feedback appreciated. We are in the process of selling this vehicle BTW..

thanks
 

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Normally, there are a number of tests that you need to do before determining whether you need replacement parts. When you say that the car keeps dying, it can be a number of things - timing, tune up, EGR valve, throttle position sensor, to name a few.
Has this car ever run properly? Can you give a bit of history on the car and maintenance? When the car is stalling, can you rev it out of the stall with the gas pedal? Is your check engine light on with the key on, and can you get a code 12 from the CEL? Have you checked fuel pressure? What exactly happens when you try to start the car - cold idle, for example. Can you keep this car running? You need to give more info.
And no, I would not replace anything without diagnostic testing......
 

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Discussion Starter · #3 ·
Affirmative...This is what I've been telling my Brother-In-Law, that there can be many thing causing an engine to die at idle. EGR was on my list. I took this vehicle in to the local Suzuki dealer two week ago and paid P2,000 to have it put on an analyzer. This was one of the things we were told when we picked it up, that it needed a new throttle body.

This engine only died about 4 times in the almost three years I've been here, and only when you turn on the AC compressor.

After the head gasket was replaced about three weeks ago, it started having this problem. That's why I am skeptical about their diagnoses.

The engine is strong, meaning it accelerates quickly, does not miss a lick, very smooth at cold idle about 1,250 RPM...My intention this week was to drive it around, get it hot and observe if the engine would die again. I never got the chance because of the pulse damper leaking, the same morning I went to do this. But before this, it ran fine, a bit rough with the AC on, but it never died, very rare. Vacuum hoses seem to look okay, except one I put the clamp on this morning. A little slop in the butterfly valve. Looked clean in the throat, but not sure about the injectors.

Yes, when the car gets to running rough, you can force it to run by keeping your foot on the brake, during stops, and keeping a little pressure on the gas pedal, once you start accelerating and during cruise speed, it runs great, without any jerkiness or stalling, very smooth. Over the years late 70's and 80's my experience has been having the same problem and having a faulty EGR valve, or some fandangled device with a wire connected to it screwed into the throttle body. This old Suzuki has crap all over it, and the wire harnesses do not appear to be in very good shape. Weather or not this particular throttle body has a computer drive and wiring going to it. I don't have a clue. This is not my strong suit.

I just do not see how a mechanic can just walk up and look at a throttle body, without running the engine or driving it, and come back and tell us it needs replacement.

Sorry I cannot give you any more info. Like I stated, this belongs to my brother-in-law, and he knows nothing about cars, so I'm trying to assist him if I can. I've only been here since Jan 2012, and we don't always drive that car, we take cabs a lot, and Jeepney's...

But, I did take this in to their shop and specifically requested an engine analyzer be connected to it, and to find the problem. This is what they told us.
 

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After the head gasket was replaced about three weeks ago, it started having this problem. That's why I am skeptical about their diagnoses.
I suspect that whoever replaced the head got the valve timing incorrect.
 

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Funnily enough, while they are putting it on their computer to see what the issue is, there are no real sensors on the throttle body that I would know of, that would indicate problems with the butterfly, throttle body, etc.
Your car will be an OBD1 car, presumably, if it was purchased from any market other than the US (which became OBD2 in 1996) - even so, I don't know what kind of 'analyzer' will indicate that the throttle body is causing the problem - again, the analyzer - if it is one that connects to the computer - only will pick up electronic information from sensors, as far as I know.

A few things you say that are interesting: When you put the A/C on, the idle gets rough (and presumably drops). The idle speed solenoid is specifically designed to control idle, particularly when you put a load on the engine. If/when you get the car running, a test would be to have the car at warm idle and put the A/C on - the idle should actually raise a few hundred rpm. Or, put the heater blower fan on high and put on the headlights - the idle should stay steady and not appreciably drop. The ISC is on the right rear of the throttle body - you can find it by following the small vacuum hose that runs from the air pipe connected to your air filter. This ISC had a small plunger inside that vibrates at 20x per second or so - this plunger can get stuck open, closed, etc. You can also pinch the vacuum hose to it with a pliers - your idle should drop considerably with the hose pinched. If you find that either of these tests fail, you can remove the ISC from the car - shake it slightly to see if it rattles - if so, then the ISC is no good. But if it doesn't rattle, then you can carefully clean the ISC with carb cleaner to get the plunger to work properly. You can test this on the bench with 12vdc to see the plunger vibrate and work.
Also note that on these older cars, wiring is becoming an issue. The ECU is connected to the ISC solenoid via the light green/black wire, which should have no voltage on it with the key in the on position, but battery voltage with the car running. If you find that the ISC is no good, while it is connected to the throttle body (and perhaps the reason why your mechanic says you need a whole new throttle body??) it can be purchased separately (or actually a replacement found in a junkyard or someone parting out the car).

Was typing this, as Rhino put in his message. You can easily check the valve timing by running a compression test on the engine - all plugs out, the F1 fuse removed, well charged battery, and floor the gas pedal when cranking for peak compression. Post your results - on the 16v, you should get at least 170psi on a stone cold engine - 190psi on a warm one.
 

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By the way, the ISC is also sometimes called the Idle Air control valve. A photo of it is here:
More Information for STANDARD MOTOR PRODUCTS AC294

If you remove it from the car, note that you will lose coolant, as two of the 3 hoses that connect to it are coolant hoses.
 

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Discussion Starter · #9 ·
Lot of good information here Bex. I do happen to have a compression tester I brought with me here. One thing I failed to mention in my long post. The upper timing gear pulley was wobbling on the cam shaft. The mechanic removed it and took it to the machine shop for repair, and re-installed it. I would assume he put it back on the cam shaft correctly.
Runs too good to be out of time in my opinion, really smooth cold idle, and runs out great. My problem at this point is getting my hands on a Pulse Damper so I can even run the blasted thing...!
 

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While you are waiting for the damper, you can do your compression test, so at least you have that verification. :)
 

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Discussion Starter · #11 ·
It's leaking pretty bad, pouring out of the damper housing. I'd be afraid of the fumes and a spark. Looks like a diaphram failure in the damper..I'm wondering about that IAS valve now, hmmm....Or maybe just do a good cleaning on the throttle body assembly.
 

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Discussion Starter · #12 ·
I'm trying to locate the ISC on this Suzuki. It doesn't have a small hose, it appears to be a 3/8 in one. My photo shows what I think is the ISC with that new clamp on it...I also saw one on you tube, some guy holding it rotating it for about one minute in his video.

I just returned from a test drive, the thing does good until you turn on the AC...In park with AC running, then put it in drive, or reverse it sometimes still dies...Takes a nose dive of about 600rpm, then tries to stabilize at 800, but it is searching 500-800rpm...

That's what I have here. Everything else run smooth, except for the idle.

Okay, looking over the engine from the drivers side, this valve, what I think is the valve is mounted to the right, or back lower side of the throttle body. near the pulse damper..Can i get confirmation?
 

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Discussion Starter · #13 ·
I finally had a chance to go and do those test on the ISC....It passed the heater, head light test, RPM dropped only 100rpm...I found the ISC valve underneath the shroud cover, near the air filter ducting bolted in front of the throttle body, with a wire connector going to it. It has three vacuum hoses connected to it, all three large about 3/8 to 1/2 inch dia. Guess the next thing I need to do is take it off and see if it rattles, if it does, then find a new one...Correct?

Funnily enough, while they are putting it on their computer to see what the issue is, there are no real sensors on the throttle body that I would know of, that would indicate problems with the butterfly, throttle body, etc.
Your car will be an OBD1 car, presumably, if it was purchased from any market other than the US (which became OBD2 in 1996) - even so, I don't know what kind of 'analyzer' will indicate that the throttle body is causing the problem - again, the analyzer - if it is one that connects to the computer - only will pick up electronic information from sensors, as far as I know.

A few things you say that are interesting: When you put the A/C on, the idle gets rough (and presumably drops). The idle speed solenoid is specifically designed to control idle, particularly when you put a load on the engine. If/when you get the car running, a test would be to have the car at warm idle and put the A/C on - the idle should actually raise a few hundred rpm. Or, put the heater blower fan on high and put on the headlights - the idle should stay steady and not appreciably drop. The ISC is on the right rear of the throttle body - you can find it by following the small vacuum hose that runs from the air pipe connected to your air filter. This ISC had a small plunger inside that vibrates at 20x per second or so - this plunger can get stuck open, closed, etc. You can also pinch the vacuum hose to it with a pliers - your idle should drop considerably with the hose pinched. If you find that either of these tests fail, you can remove the ISC from the car - shake it slightly to see if it rattles - if so, then the ISC is no good. But if it doesn't rattle, then you can carefully clean the ISC with carb cleaner to get the plunger to work properly. You can test this on the bench with 12vdc to see the plunger vibrate and work.
Also note that on these older cars, wiring is becoming an issue. The ECU is connected to the ISC solenoid via the light green/black wire, which should have no voltage on it with the key in the on position, but battery voltage with the car running. If you find that the ISC is no good, while it is connected to the throttle body (and perhaps the reason why your mechanic says you need a whole new throttle body??) it can be purchased separately (or actually a replacement found in a junkyard or someone parting out the car).

Was typing this, as Rhino put in his message. You can easily check the valve timing by running a compression test on the engine - all plugs out, the F1 fuse removed, well charged battery, and floor the gas pedal when cranking for peak compression. Post your results - on the 16v, you should get at least 170psi on a stone cold engine - 190psi on a warm one.
 

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Discussion Starter · #14 ·
Throttle Body

I went back and pulled the cover just in front of the throttle body, and saw what I think is the ISC, has three hoses and an electrical connector going to it, does that sound like that's it? Hoses coming from the air filter ducting, and some going out and down below the intake manifold.

Funnily enough, while they are putting it on their computer to see what the issue is, there are no real sensors on the throttle body that I would know of, that would indicate problems with the butterfly, throttle body, etc.
Your car will be an OBD1 car, presumably, if it was purchased from any market other than the US (which became OBD2 in 1996) - even so, I don't know what kind of 'analyzer' will indicate that the throttle body is causing the problem - again, the analyzer - if it is one that connects to the computer - only will pick up electronic information from sensors, as far as I know.

A few things you say that are interesting: When you put the A/C on, the idle gets rough (and presumably drops). The idle speed solenoid is specifically designed to control idle, particularly when you put a load on the engine. If/when you get the car running, a test would be to have the car at warm idle and put the A/C on - the idle should actually raise a few hundred rpm. Or, put the heater blower fan on high and put on the headlights - the idle should stay steady and not appreciably drop. The ISC is on the right rear of the throttle body - you can find it by following the small vacuum hose that runs from the air pipe connected to your air filter. This ISC had a small plunger inside that vibrates at 20x per second or so - this plunger can get stuck open, closed, etc. You can also pinch the vacuum hose to it with a pliers - your idle should drop considerably with the hose pinched. If you find that either of these tests fail, you can remove the ISC from the car - shake it slightly to see if it rattles - if so, then the ISC is no good. But if it doesn't rattle, then you can carefully clean the ISC with carb cleaner to get the plunger to work properly. You can test this on the bench with 12vdc to see the plunger vibrate and work.
Also note that on these older cars, wiring is becoming an issue. The ECU is connected to the ISC solenoid via the light green/black wire, which should have no voltage on it with the key in the on position, but battery voltage with the car running. If you find that the ISC is no good, while it is connected to the throttle body (and perhaps the reason why your mechanic says you need a whole new throttle body??) it can be purchased separately (or actually a replacement found in a junkyard or someone parting out the car).

Was typing this, as Rhino put in his message. You can easily check the valve timing by running a compression test on the engine - all plugs out, the F1 fuse removed, well charged battery, and floor the gas pedal when cranking for peak compression. Post your results - on the 16v, you should get at least 170psi on a stone cold engine - 190psi on a warm one.
 

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Discussion Starter · #15 ·
ISC Valve

See Link: Idle Air Control Valve Standard AC294 | eBay


I went back and pulled the cover just in front of the throttle body, and saw what I think is the ISC, has three hoses and an electrical connector going to it, does that sound like that's it? Hoses coming from the air filter ducting, and some going out and down below the intake manifold.
 

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Yes, that is the photo of it. Only one of those hoses is vacuum (coming from the air pipe). The other two will contain coolant, and you will lose some when you disconnect this ISC.
When you tightly pinch the vacuum hose coming from the air pipe, your car idle should stumble considerably. If, when you are idling, you put the A/C on, and the idle gets very rough - it is the job of the ISC to actually raise the idle in this situation, up to about 1100 rpm or so, from the steady, warm 800 rpm idle.
 

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Discussion Starter · #17 ·
Update: I'm getting there. I pulled off the ISC valve, it was crudy, filthy full of crap, probably never been cleaned 17 years now...I cleaned it out good blew it out, then skirt some WD-40 in there. Then did the 12V test, and it worked...! Click-click, moved about a 1/4 inch, spring is still strong. Re-installed it, cranked the engine, got it hot, then I pulled the 2-pin connector off, and the idle indeed dropped about 200rpm, reconnected and it increased, so at least it is responding now. Drove it around a bit, it still seems to be hunting for that happy spot, when I run the AC, standing still in drive or reverse. Turn off the AC it gets steady. So everything is good except when running the AC, gets down around 400rpm initially then climbs back up to around 7-800. Something it didn't do before cleaning the ISC valve.

I freaked when I saw the coolant, didn't make sense that coming out of what i thought was an all air operated valve. Now I have to figure out, what else it could be making it unstable with the AC operating. He just had it tuned up too, new plugs, etc...

Maybe I should pull the throttle body and give it a good cleaning as well. What do you all think. Any other ideas, before I do this. We still have buyers coming in too and driving the thing, so it makes it hard for me to get a window of opportunity to work on it...What about the fuel regulator, or EGR valve, or any of the smog junk on these things...?


Yes, that is the photo of it. Only one of those hoses is vacuum (coming from the air pipe). The other two will contain coolant, and you will lose some when you disconnect this ISC.
When you tightly pinch the vacuum hose coming from the air pipe, your car idle should stumble considerably. If, when you are idling, you put the A/C on, and the idle gets very rough - it is the job of the ISC to actually raise the idle in this situation, up to about 1100 rpm or so, from the steady, warm 800 rpm idle.
 

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Discussion Starter · #19 · (Edited)
I read most of the pages, don't know what a TPS is...Answers are all over the board. I may start a new thread pertaining to our problem here. The AC in this Sidekick is also not putting out cold air, he replaced the compressor last year, fixed a few leaks in the evaporator, held for awhile but still not good. Not sure if this is related to the idle problem.

After I cleaned the ISC valve it did pass all the test, except for the AC. It improved yes, but when I turn on the AC, RPM drops about 500 and stays down, then starts surging up and down...I wonder if there could be a specific fix, but I know unfortunately there are many things which could cause the problem. One thing this guy didn't mention is an RPM surging problem.

With the AC running and in drive, foot on the brake stopped, the RPM pulsates up and down from 600 to 850rpm...That should point to a more specific fix, should it not?
 

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You say the AC does not have a charge? (or is low on a charge?)

It might be the AC clutch cycling as it kicks in and out as the system is trying to get the pressures right... and not making it.
 
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