# High idle cold start problem 16v swap



## 84rocco16vswap (Jan 4, 2014)

So I have a 1984 16v swapped scirocco. It's been having issues when I start it up in the morning when the motor is cold. First before I explain. It's a swap I did one year ago. I have all new sensors, distributor, cap, rotor and wires and plugs. New coolant temp sensor. Isv seems to be working, buzzing and humming. Idle and wot switches working. You get the works. 
So when I start the car up in the morning I have to press on the gas a hair after it fires and starts to barely idle at say 800rpm. And I will hold my foot on it at 1100rpm for say almost a minute if not even that. And then the car will start to idle on its own at 1500rpm. And it will stay idling at 1500 then jump up to 2000-2150 and when it jumps if I blip the throttle it will go down to 2000rpm. Then it will stay there for a few minutes then finally when the motor is warned up. It idles at 1100 rpm which is almost perfect. But it seems to sound like it misses a little sometimes. Like it's not getting enough fuel ? But all parts are working. So that makes me think that it needs more fuel. To help with the cold start in mornings ? Maybe air/fuel mixture outta wack? Cause I've messed with it before. And who knows who messed with it before me ? Also might I note that if I leave the idle switch contacting when throttle is closed like it's supposed to when I start it cold, as in said above here it does the same thing if I were to make it not contact? Is there a issue with my switch ? Also my dpr mA readings are coming out at 35mA+. I really need help ASAP! This is my daily driver. It's cis-e 88 16v swap :banghead:


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## kwak (Apr 7, 2005)

For the idle switch, at idle touch the ISV and feel that it hums. Then reach over and turn the throttle just enough so the idle switch is not pressed. Does the ISV stop humming? If so then it is working correctly.

The following settings are for a CIS-E PL (16V) engine.

Idle speed should be between 850 and 950. If it is at 1100 then it should be adjusted down.

The DPR at idle (with the engine warm) should be between 1 and 10 mA and be fluctuating (average of 5 or more). At 35 mA yours is too high so the mixture has too much fuel.


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## 84rocco16vswap (Jan 4, 2014)

Okay. I will try that isv test this morning. It does humm and buzz. Just not sure if it stops humming or buzzing after idle. Like your saying. As for the dpr mA. No matter what I do when I turn the screw with the car warm the mA is still very high. If I turn the screw to get less gas then it bogs really bad. And if I tie it do do more fuel then it has smoother idles. I use to get very bad gas mileage. 25 max. And I had fuel issues. Clean dpr and injectors. And set air plate basic adjustment and basic adjust off the roller bearing at 19mm per bentley,chiltons. And when I installed it the car wouldn't get enough gas so I started adding more gas from there. An that's where I'm at before I posted this post in the beginning. Need help. Ive been through the whole car inside and out. I tried attaching pics.


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## kwak (Apr 7, 2005)

I don't have the tools to walk through all of the steps in the Bentley but I have been through some of them.

In the Bentley use engine code PL for a CIS-E 16V. The manual is pretty good at saying, set up the test this way, check this, if the test does not work then you know what part is bad.

Have you at some point verified the fuel pressure settings? I had the opportunity once to borrow the fuel pressure test setup from a mechanic to check mine.

For idle speed, idle mixture, and dpr settings see the specs in in chapter 3 section 6.7. Under CIS-E note that it says to first confirm ignition timing and idle speed before adjusting the mixture.

Setting idle speed is in chapter 3 section 6.3 under Adjusting Idle Air Stabilizer Duty Cycle (engine codes ... PL). There are some setup conditions which must be met to not incorrectly influence setting the idle speed.

Then back in the idle mixture section a CO meter is really needed to get the idle mixture correct. If it is not already obvious, the idle mixture screw (3mm) is the mechanical mixture adjustment. Once this is correct the dpr is used to electronically adjust mixture for different conditions.

I thought of a question. Is your dpr reading of 35 mA at idle fluctuating or steady?


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## 84rocco16vswap (Jan 4, 2014)

yeah i know its a 16v PL 88 scirocco swap. with knock box. wired in just the one wire per a2resource.com evrything thing is done right in the swap also. will double check grounds also. i dont have a bentley for my 88 16v swap. I have a chiltons and a haynes. I also have a 16V training pamphlet that tells how to adjust etc. but my question is... since i deleted the charcoal canister and stuff will that affect the mixture settings extra, timing ? will make sure to set ignition timing after fully warm at 6degrees btdc. i can use my volts meter to do dpr mA. i already made a jumper harness. and as for the isv. i think i can adjust it by using the duty cycle on a test plug on harness. i know what your talking about. but im not having 100% luck getting the car to run right. yeah i know the 3mm allen is the basic mixture adjustment and the dpr takes control after idle. and at wot it always maintains lambda stoichometric 14.7:1 air fuel. will a bad O2 sensor be at fault here? the car also seems to have a little rev hang at 2000 rpm. and seems to be a little sluggish but not much. just seems to have wrong air fuel adj. cause right off from idle its a little off with throttle response. and i cleaned the fuel dist plunger and injectors. and set air plate cone adj per wire under plate, not leaf spring. also set basic adj at 19mm. measurement from bottom of dist to roller bearing. and when i got it back together and primed system. it needed more fuel so i gave it more fuel till it stayed running good and getting decent mileage. probly 30 mpg


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## kwak (Apr 7, 2005)

Thanks for additional information. Knowing you don't have a Bentley I can look up stuff for you.



84rocco16vswap said:


> since i deleted the charcoal canister and stuff will that affect the mixture settings extra, timing ?


On the charcoal canister delete, what do you have in the left over airboot hole? It can affect idle speed. Also, if the hole is wide open the oxygen sensor will see the mixture as lean and increase the dpr number to add fuel.

Instruction for setting idle speed. Unplug the ISV air hose from the breather hose. Leave the little red restrictor plug in the end of the ISV air hose. Unplug the charcoal canister hose from the airboot and insert a plug with a 1.5mm (.059") hole in the airboot hole. ISV duty cycle should be 23-27%. If the duty cycle is incorrect turn the idle air bypass screw on the side of the throttle body.



84rocco16vswap said:


> will a bad O2 sensor be at fault here?


That is why I asked,



kwak said:


> Is your dpr reading of 35 mA at idle fluctuating or steady?


Fluctuating means the ECU is getting a signal from the oxygen sensor and is adjusting the mixture. I will need to look up how to test the O2 sensor.

A high dpr number like that can also mean the coolant temp sensor (2 wire) is not working correctly. The colder the temperature the higher the mixture (dpr value). You can test the ohms between the two sensor terminals and look up the value in your manuals or let me know and I will look it up in the Bentley.


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## kwak (Apr 7, 2005)

84rocco16vswap said:


> and at wot it always maintains lambda stoichometric 14.7:1 air fuel.


Stoich is maintained at steady throttle or idle. The ECU watches the O2 sensor and always sends the mixture to the other side of stoich. That is why the dpr signal fluctuates. At wot the ECU drops the oxygen sensor out of the loop and goes to a fixed large value on the dpr. That is why if the 3mm mixture screw is off so the mechanical mixture is off then the ECU has no way to compensate at wot.


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## 84rocco16vswap (Jan 4, 2014)

yeah no problem. thanks for helping me. i understand yeah if the dpr ma is fluctuating then it is geting a signal from the o2. i have the hole in the intake plugged. will describe further in this reply. and the coolant temp sensor i replaced a few months ago but maybe the one i got is defective? the connector doesn't snap on as tight as the old sensor. and maybe my old one was good? i have a few spares. they all are the right white colored cts. i will switch and see? 
as for the isv duty cycle adjustment. my 16v scirocco training manual says this. chiltons says a little. my tank vent hose is in engine bay. my throttle body is on drivers side of car etc. cis-e e3 aka ke-jetronic

get car warm of course. make sure no vacuum leaks. make sure timing is correct. 
hook up test meter to plug (grey blue test lead). idle switch closed. below 1200 rpm
insert 1.5mm t connector in intake boot. substitute t 1.5mm insert part # 026 133 382 D. ( but what end of the Y part do i insert into intake boot?)
and unhook large hose at crankcase and allow fresh air in. 
adjust with idle air speed/bypass screw on the back of the throttle body to 23 to 27% duty or 21 to 24 dwell my chilton says this to the left for PL, and it also shows a picture of cis-e motronic and motronic has the red thing your talking about. my 16v training manual says 26-30% duty and adjust to 29% + or - 1% for PL. the chiltons says that my 16v manual adj spec is for HT or RD engines. but its not a 16v scirocco specific manual. all my vaucum lines are routed just like the 16v manual says also. not much difference between cis-e and cis-e motronic. 
you said unplug the isv air hose from the breather hose ? you mean the crankcase large end of hose ? that big hose has three ends. one end goes to bottom of airbox. one end goes to crankcase. and one part where it t's has a white restrictor in it that goes to the right side of the bottom half of the intake manifold. on the air intake boot i have a black Y plug on one hole where charcoal canister hose was. the black y is part # 026 133 382 D. one hose goes to left side of intake manifold for air shroud injectors, at air boot side it has a blue connector. and one hose loops to isv. and that connects to top where cold start valve mounts on right side of intake, where the breather hose with the white restrictor in it. just like a normal 16v scirocco? thats the way it was when i did swap. so are you saying my hoses are wrong? 

and you said red restrictor ? i only ever seen thiose on cis-e motronic on 2.0 16v. the chiltons has a picture. its like what you said in your adjusting duty cycle but it seems mine is different. the throttle body on those is on the left etc. the lower half of intake is the same though as my car. i studied a few lol. so maybe there is some miscommunication? all my hoses are done right. i just double checked. meed help still.


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## kwak (Apr 7, 2005)

It looks like between your 3 manuals you have good information.



84rocco16vswap said:


> the coolant temp sensor i replaced a few months ago but maybe the one i got is defective? the connector doesn't snap on as tight as the old sensor. and maybe my old one was good? i have a few spares. they all are the right white colored cts. i will switch and see?


Instead of just trying a different one, use a multimeter and measure the resistance between the two terminals. Do that for the one in the car and one (or all) of the spares. Also, does it feel like the cts connector might not be making good contact? A test might be... while looking at the dpr value, hold the cts connector down better and see if the reading changes.



84rocco16vswap said:


> ( but what end of the Y part do i insert into intake boot?)


My car doesn't look like the T or Y fitting in the picture but here is what the manual looks like. The hose to the canister as on one leg. Then at 90 degrees is the one normally plugged into the airboot. Then sort of straight across from the hose is the one which has the small hole in it that is used in test mode.



84rocco16vswap said:


> 23 to 27% duty or 21 to 24 dwell my chilton says this to the left for PL, and it also shows a picture of cis-e motronic and motronic has the red thing your talking about. my 16v training manual says 26-30% duty and adjust to 29% + or - 1% for PL.


Bentley says 25-30% on 8V engines and 23-27% for 16V. Maybe go for a value which works for all, 26-27%?



84rocco16vswap said:


> and you said red restrictor ?


I wouldn't worry about the color. But the restrictor/connector to join the ISV hose to the crankcase breather hose must be in place on the ISV hose or it throws off the idle. I noticed this when I had a loose ISV hose unplugged from the restrictor.



84rocco16vswap said:


> thats the way it was when i did swap. so are you saying my hoses are wrong?


It doesn't sound like it. But my car does not have air shroud injectors so you have some stuff I cannot check on my car.

Maybe in describing what you have you will notice something. Or hopefully someone else reading will spot something. My only engine related skill is knowing how to read a manual and follow what it says.


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## 84rocco16vswap (Jan 4, 2014)

yeah think i can get some where with the three manuals. but you check resistance on the CTS. like ohms ? both leads of multi meter to both leads on CTS? what should it read? 

The car seems to idle high at like 2000 rpms till the temp is half way minimum. maybe i have a sticky ISV? or a vacuum leak? or a bad ground somewhere ? i am going to check all that i just mentioned. also gonna check micro switches. do you know procedure? 

and the duty cycle, i figured out what part of the y that has the 1.5mm restrictor to allow fresh air in. 


i will let you know what i find out. wish me luck :banghead:


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## 84rocco16vswap (Jan 4, 2014)

Well I tried my other cts and the car would only start if I had my foot on the gas.

And the newer one I had in the car, the plug from the ecu seemed to not fit very snug. So I got another rubber insulator for the inside of the plug that's supposed to help with moisture. The plug fits nice and snug now. And the car starts right up with it. So it seems to be working correctly. But the plastic part of the sensor moves a little and stops? But sits and stays in one spot and seems not not be affecting the sensor. So the cts problem is solved ? 

Also might I say that the car still idles high at about 1800-2000 rpms until the car warms up to half way minimum on coolant temp gauge. And when it idles down it idle pretty good and steady at 1000-1100 rpms. 

The throttle response seems to be off some, little like it's running lean? but not much at all. But the car seems to have rev hang at about 2000 rpms and sometimes the tachometer bounces. But no mis-fires. All 4 cylinders firing and all four spark plugs read the same, as in color wise. A lil black. But I haven't changed my plugs cause they work fine. So they could be dirty from before my adjusting etc when I was running way rich. 


The car seems to run better when it's warm. So it's rev hang isn't as bad when warm. But still is some noticeable rev hang at 2000 rpms. 

Also air/fuel mixture seems to be off some... 


Help


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## kwak (Apr 7, 2005)

Woohoo! I just found an online copy of the Bentley manual. These don't seem to stay up very long http://vnc.thewpp.ca/stuff/bentley/ep0niks.ctech.ca/vw/eva2/index-2.html. Click on "Fuel System - Gasoline", then scroll down to section 6 for CIS-E for everything I am looking at.



84rocco16vswap said:


> check resistance on the CTS. like ohms ? both leads of multi meter to both leads on CTS? what should it read?


Yes, that is how to check. The Bentley manual, and maybe one of your manuals, has a graph with a curve on it showing what the CTS ohm reading should be at what temperature. If your engine is cold, get the air temperature and the ohms and check the graph.











84rocco16vswap said:


> The car seems to idle high at like 2000 rpms till the temp is half way minimum. maybe i have a sticky ISV? or a vacuum leak? or a bad ground somewhere ? i am going to check all that i just mentioned. also gonna check micro switches. do you know procedure?


Only for the switches. Take the connector off the ECU and do the electrical tests in this Bentley section: http://vnc.thewpp.ca/stuff/bentley/ep0niks.ctech.ca/vw/eva2/FU01/ch6.4.5.html. Since you will have the connector off go ahead and do all (or most) of the tests. Might as well check. I've done this before with my car.

When there is a rev hang and you are sitting in the driver's seat, have you tried using your toes underneath the gas pedal, lift your toes, to see if the idle speed drops? I used to have a sticky throttle blade giving me an idle above 1000 rpm instead of 900 rpm, and that trick would work for me.

Otherwise your temperature dependent high idle has me confused. It keeps making me think too much air is getting past the closed throttle blade.



84rocco16vswap said:


> i will let you know what i find out. wish me luck :banghead:


Definitely, good luck. :thumbup:


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## 84rocco16vswap (Jan 4, 2014)

Okay. So I fixed the connection on the cts and car starts fine.

The cold start valve is squirting in the morning from the thermo time switch and the cts is working properly. I'm assuming cause i unplug it the car dies. 

I still need to perform some electrical tests. I will let you know the outcome. Thanks for the help in advance kwak :thumbup:


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## chris_b3_coupe (Aug 3, 2014)

I am also having idling problems on my Audi b3 coupe, it previously had a 2.0 8v engine and I dropped a 2.0 16v ace engine into it and when the car is cold it's very hesitant and splutters and wants to stall could that be the cold idle valve causing it to happen as I am miffed


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