[mdss]

Hi guys



yet another small problem!!



All engine codes are normal recently changed the hall sender but the problem was there before and remains there now. Although car runs much better now its done.

Ok here goes... when i turn the car on from cold it idles up to 1000-1100 which is fine but as soon as i touch the throttle to move(reverse the car) and let go of the throttle the car runs lumpy and idles low and rough, sometimes it may turn off i can keep it going with the throttle if i drive off the car runs fine and literaly after 1/4 of a miles its fine. No other running issues.



I have checked all the spark plugs for water and dust etc alonmg with all sensor plugs and cleaned them all but the problem persists. I even removed the <acronym title='mass air flow'>MAF</acronym> and cleaned the metal flap which was very dirty which seems to have helped the car once running but not helped the cold start problem.



Could this be the DME relay any help is warmly appreciated.

as usual thanks in advance

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[DaveN]

Search the forum and find the instructions to jumper the DME relay socket and give that a try when it's cold. It will just turn your pump on permanently for a while but that's not harmful. If you find your problem clears it's definitely that pesky relay. Most of us carry a spare in the glove box.

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[mdss]

thanks will do a search now much appreciated

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[mdss]

think i will just buy anew relay it has not been changed in 8 years and for the small cost it seems worth it.

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[94SilverCab]

Perhaps cap and rotor if the relay doesn't work.



Jay

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[mdss]

cap and rotor are brand new bud and seem fine. pain really as the car runs so nice. It out ran my brother in laws subaru impreza turbo(prodrive pack) 245bhp and 255ft/lbs in a straight drag from 20mph it pulled a full cars length which is'nt bad when you consider its nearly 20 years old.

I know his car is quick as it used to be mine not so much the power but the torque is good and as it is prodrive packed the torque curve is very good.

DME relay tomorrow more expense......

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[rl968]

sounds like a similar problem I had, ICV.

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[flash]

the programming goes through a 60 second startup cycle. the mixture is enriched for that period, and then quickly tapers off to normal.



do you have an aftermarket chip in there?

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[mdss]

Hi guys, changed the DME relay for the 993 vrsion today along with a new water temp senor, still the problem persists.

Flash you are correct the car has a promax 7100 chip in it but i didn't think that would make a difference.

Think the last thing is the ICV i will take it out and give it a good clean this weekend cant think what else it could be.

Will be ineterested to see your thoughts on the chip flash as although the car does'nt run rough once moving it idles lower than it should until completely warm, which is the opposite of every other car i have had usually they idle high and as they get warmer they settle.

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[flash]

that chip is indeed known to have a few "issues". i've seen the maps too, and they aren't exactly perfect. under most circumstances it is "fine", but i can see where it could be problematic at times.



change the chip back to stock and see if the problem persists.



i'd also poke around just to be sure you didn't have any vacuum leaks.

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[rl968]

cleaning ICV won't necessarily fix it if it's bad, could be an electrical issue inside of it.

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[mdss]

Thanks flash will change the chip tomorrow and see what happens.

If that fails to work i will just buy a new ICV as rl968 makes a good point

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[flash]

i'd verify no vacuum leaks before messing with the ICV. they don't generally fail, and are a pain in the butt to get to

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[mdss]

surely if i had a vacuum leak then i would notice it at high speed ?

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[flash]

nope. car will run ok, though down on power a touch, depending on the leak. fuel economy might also suffer.



put a gauge on there and see what it says.

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[durtkillon]

If you rule out vacuum leaks first, the ICV would be my next suspect and here is why:



I just cleaned my ICV this weekend. I was experiencing some rough idle. When I'd pull up behind another car at a stoplight, I could see my headlights rattling from the rough idle. After the ICV clean, it has improved tremendously, particularly when cold or in low gears like reverse or 1st (I have a TIP).



Upon inspecting my ICV, I found a lot of crud inside. The black goo not only restricts the flow through the valve, but the actual operation of the valve itself. The valve gate operates on pulses from the DME and is spring loaded. This means the goo can create an obstruction for the gate and even though the motor drives to the correct position, the gate spring merely compresses and the intended air/choke does not occur.



I hit it with half a can of <acronym title='mass air flow'>MAF</acronym>, a tiny toothbrush and tested both the open and close function with a 9V battery. It seemed to function well after cleaning so I reinstalled it. It took about 2 hours, including a trip to the auto parts store to get some extra hose clamps and a minor Turrets Syndrome attack. The bolts are tough to get to with the 1/4 socket driver and the SC kit added a few more obsticles. I just took the throttle body off and zip tied it to my brake resevoir lines to create easier access.



I'm a believer now in the ICV cleaning procedure, especially after looking up the price of them <img src="/forum/images/smilies/968/glare.gif" class="smilie" alt="" />.

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[mdss]

I changed the chip the car felt flat as a pancake and there was very little improvement. i think i will clean the icv and see. To be honest today i showed a little patience and started the car and let it idle for 2 mins before i reversed it. The car was fine using this procedure maybe i should just do this each time as its a sensible option and good for the car.

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[flash]

i'd still be looking for a vacuum leak first.

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[Byte]

I have the same issue from time to time. My issue happens in drive (tip). It doesn't matter if everything is warmed up or not. Waiting see if cleaning the ICV helps you.

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[flash]

the tip programming has a very serious warmup cycle to prevent damage to the transmission. it takes a couple of minutes before it allows you to go full throttle.



for clarification, for the first 60-75 seconds it is NORMAL for the car to hesitate. the mixture is seriously enriched during that time. if you stab it it will cough. if it is cold outside, moisture can cause issues. if there is a small vacuum leak, and they are common, this will be exaggerated. the same thing will happen if the O2 sensor is old and tired (they only last 60k miles).



the ICV is rarely the cause of a problem. the one on our car is a pretty simple device, and does not normally fail. it can get gummed up if you don't maintain your car, but normally that thing can go forever without any attention.



i would be looking at the throttle body adjustment or a vacuum leak.

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