Yes, it probably is due to the idle mixture being out of adjustment. I think I'm right in saying that over 2000 rpm the mixture is controlled by the EHA, which is why it will run above that speed, but not below.

So, how to deal with it.

You can adjust the level of the flap, there's a pin that you can knock in to increase play. However, unless you've changed the fuel distributor, its extremely unlikely the flap needs adjustment. Adjusting this pin is kind of a one-off because to reverse direction, you need to disassemble the whole shebang so don't go there unless you are absolutely sure.

Much more likely that you adjusted the position of the airflow sensor pot when you replaced it after cleaning. This unit measures the position of the flap so if flap position is the root of your problem, you should be looking at the airflow pot instead of the adjustment pin. There is a procedure for measuring current at the airflow pot to make sure it is in the right position, do a search on airflow sensor potentiometer to find the multiple threads on this. i'd also suggest refining your search to find threads involving stevebfl if you want the real deal.

Its unlikely you have the ICV in backwards, can't remember which way the arrow goes but you know it's in the correct position if you can see the arrow on top, the hoses are engine side and the electrical connector fan side. Check you are getting power to the ICV at KOEO, should be 6v. You should also hear the unit click inside when you turn on the ignition as it switches from rest to idle position.

Mixture adjustment: You really need two people to recover from an incorrect mixture setting: one to crank the engine, the other to tweak the mixture screw in order to get the car to start and idle, otherwise you'll be back and forward until you get it right. Your plug conditions point to a rich mixture but inability to start suggests a weak idle mixture. This may, of course, be due to something else wrong in the mechanical fuel delivery system, but deal with adjusting the idle mixture first.

A small adjustment goes a long way with this, so if you can't remember where you started from and adjust back to that, try by backing off counter clockwise 1/2 a turn. Try to start the engine and if it won't start, adjust clockwise 1/8 turn and try again, keep going until it starts to pick up. Then, once you're at a rough idle, try slight adjustments either way until the idle smooths out. I assume you know you have to push down on the adjuster to engage the screw before it will turn.

If you have a O2 sensor and cat converter, you can adjust the closed loop running (when engine is warm) by monitoring the current at the X11 connector. Do a search on this, plenty of posts on this subject.

If you don't have lambda control (O2/cat), once you have a smooth idle - and lets hope it works this far for you, you can get an idea of where the mixture setting is by squirting a small amount of carb cleaner into the flap and seeing how the idle responds. If it bogs down, you're too rich and if it speeds up, you're too lean. My mechanic adjusts it by feel, and after you've been through the above procedure, I reckon you'll be confident enough to adjust by feel yourself. You can see/feel the difference between a smooth idle and a slightly rough one. There is a suggestion going around that the 103 engine has a 'twitch' at idle, which I'm not sure I subscribe to but I wouldn't rule it out.

The correct procedure is to use an exhaust gas analyser and adjust back from that but if you're doing that, chances are you're already at the dealer.

One other point, if your motor mounts are shot, no amount of adjustment is going to get you a smooth idle so don't discount that as a factor when you're twiddling.

good luck

Thank-you so much for your response and detailed directions.
I shall have a go at the job again in the morning. And I'll keep you posted, again thanks for your help.
Phil

Should the ICV make the engine idle higher or lower when disconnected?

When I disconnect the engine increases... ICV could be problem...

OK, sounds like you've got the engine started and idling. That's good.

You need to do a search on ICV to find out all you need to know, all the information is here in this forum, but basically it comes down to this:

No power to ICV, the fuel system is in limp home mode, idle is 500-600 rpm but lumpy.

If you have 6v power to the ICV then it should function. If you can hear it clicking when you go to KOEO, its working. It may be gummed up inside so take it off and give it a good clean with carb cleaner.

Control of the ICV, which is there to maintain a steady idle with and without the AC and Power Steering pumps working, is achieved by the Engine Control Unit (ECU) changing the current flow. Power and current from the ECU goes through the Over Voltage Protection Relay (OVP) so if your OVP isn't working, you don't get any power to the ICV, which means you don't get any idle control.

If you disconnect the ICV and the idle goes up, what are we talking about? From 500 to 600rpm? 900 to 1000 rpm?

Still no idle on its own- must hold open flap to start-run-then idle.

When disconect ICV lead- idle rises 250 rpm (650-750ish)

I'll check the OVP now- (replaced 6 months ago...)

In looking over the OVP wiring- I found a black lead that when touched caused a clicking sound over by the ABS mechanism.

I wigled the wire and it broke off the base of the OVP pin housing.

Would this poor connection cause any no start issues?

Phil

I second what simmo300e says. Instead of measuring current I think it might be easier to measure voltage: Adjust the idle by varying the position of the potentiometer. After the idle has stabilized, fine tune the position of the potentiometer till the voltage corresponds to 0.75V (+/– 0.1).
There is a thread with pictures about the correct procedure:
http://www.peachparts.com/shopforum/tech-help/62133-300e-test-sticks-10%25-duty-cycle.html?highlight=10%25+duty+cycle
I would leave everything else alone for the moment. Good luck, Bruno

I can't get the engine to run at idle so adjusting the pot does nothing.
The only way the engine runs is with the flag held open aprox. 1/4" buy hand.

The OVP is fine- wire all fixed...

I don't seem to get a click from the ICV like I used to though... if the ICV is not functioning would it affect the flap?.. and how can I diagnose the ICV?

Cheers and thanks for all the help.

Phil

After thought...

I have yet to adjust the trim setting inside the pot...is this an issue?

keep in mind the thing ran great for an hour before it did'nt want to start anymore...

Very Frustrated
 

:mad: :mad: OK I'm getting very pissed here-I'm tired of working a car that does not respond to any changes..

Adjustments to the pot - no changes.
Adjustments to the idle mixture- no changes.
Adustments to you name it no f!@#$ changes.
====================================

This is the current status...

Turn over ingnition- car stars and runs for five seconds then dies...
Smell of fuel evident...
I prop open the flap 1/4"- turn over ingnition- car runs with flap held open only..

It seems no matter what I adjust this status remains the same. The plugs get wet, I wait for them to dry, do it again.

It's always flooded...
It wants to start...

What the f#$$%^ am I missing?????



Frustrated Phil :mad: :mad:

Solved
 

Well it runs now!

This is what I did:

Cranked the idle mixture several turns to rich.
Left the flap closed
Disconnected the ICV leads.

It idles and runs like a charm!

I tried reconnecting the ICV when running and it stalls the engine, so it stays disconnected for now.

I hope this helps others in the future- I know I've learned a ton of tricks during the research process to solve this problem.

Phil.

well, your original problem may be solved because you can now get the engine started and idling, but you are far from finished.

I predict your fuel mileage will drop through the floor due to the idle mixture being too rich and/or the engine will be stalling on deceleration because you've got no idle control. I'm guessing you've got an auto trans so the stalling may not be so obvious. If you were driving a stick, you'd notice it the first time you put the clutch in to change down.

I think you may have already found your problem in the dodgy wiring at the OVP junction. You should check for voltage at the ICV socket now you've got it disconnected. You should be getting about 6v when the engine is running. If there's no reading, you need to start checking connections and cables to find out why.

good luck

I do have voltage at he ICV when running. I thnk it could be a mechanical problem in the ICV- when inspecting I noticed that the rotary valve did not close all the way could this be...

I have not realized any stalling problems at all, in fact this car has never run so well. Good starts, smooth idle, no surging or hunting.

BTW, I also did some other tweaks along my journey including bleeding the fuel distributor lines, adjusting the EHV, cleaning the idle pot (which did'nt look bad at all - maybe never needed it).

I will continue to monitor and report back. (I'm going fishing with my sun now)

Phil

Well Simmo your predictions seem to be as accurate as CNN with Katrina.

- Fuel mileage is poor due to rich conditions.
- ABS light somes on goes off.
- Idle hangs above 1000 r.p.m. occasionally.
- Wiggle the OVP relay and things get wacky..

Question is why... I tested the relay two days ago and o.k.- could be somewhere in the wiring?

Phil

not sure if that's a compliment or not, we have a different view of CNN in this part of the world :)

Anyway, to address your concerns, your ICV isn't jammed, the setting at rest (without power) does leave a gap exposed. This is the limp home setting. When you apply power, the rotary valve flips to open sufficiently for the correct idle setting. The size of this opening is then varied by changes in current to counter additional loads on the engine caused by the AC compressor, power steering pump and to maintain idle on deceleration. (The deceleration switch notes that you have taken your foot off the gas and shuts off the fuel supply. Without the ICV working to compensate, this can cause the engine to shut off. )

Your fuel mileage is bad because you've adjusted the idle mixture settings to compensate for the loss of idle control. With the correct mixture, disconnecting power to the ICV would result in a lumpy idle of around 500-600 rpm. By adjusting rich, you are moving the limp home idle up to what would be regarded as normal.

The ABS circuitry is also linked to the OPV. Not sure how exactly seeing as I don't have ABS in my car so have never had to investigate this particular bit of kit but the light coming on apparently indicates a malfunction at the OPV.

Idle is going above 1000 rpm because your ICV is powering up intermittently. If you put a voltmeter across the ICV terminals and watch while your idle fluctuates, you'll see what's happening. With no power, your idle is running at a pseudo normal 800 rpm due to the rich mixture, with power the ICV is taking over and the rich mixture combined with increased airflow results in an rpm boost.

Logically, either the OPV is acting up or there's an interruption of power going into or coming out of the unit.

I would first check you are getting a good connection in the sockets, there may be some corrosion in there or the sockets may be loose.

try just wiggling the wires and see if that has any effect. do this all along the route from ICV to OPV and see if you can reproduce the problem. this would indicate a problem with the wiring.

How new is the OPV? They don't last for ever. Prise open the crimping holding the casing to the base and check the soldered connections on the board inside. They often corrode and can be resoldered to restore the connection.

my problem was an ECU gone bad. I could cut and restore power to the ICV by banging on the casing, see if that works for you. better hope this isn't the case coz its the most expensive fix. A new unit costs $1200 although i managed to pick up a secondhand one for half that.

good luck

actually, looking over your previous posts i think you've already found the problem. remember the black wire?