Possible vacuum leak? High spark timing at low rpms

p.s. high spark at idle is fairly normal.

also if your car has 80% load at idle the engine is lugging for some reason and the pcm will chunk spark at the motor to try and raise/control the idle speed.

small idle speed adjustments are quicker and more effectively control by adding or subtracting spark, than it is by manipulating the IAC. IAC is for large idle corrections and for controlling engine speed after taking your foot off the gas to prevent the engine from dying, spark is used to fine tune the idle from that point.
 
It idles perfectly, i thought the trims would let me know if it was running rich or lean in the sense that if it was always showing to add 10 to 15% on both ltft and stft, i'd know something is not right, which is what was happening before i changed the pump. Now it really does run better all around, but the load % is still high and i still feel it wastes gas at idle. I am also comparing it to my favorite mark i've owned, which was a 93. I know it was slightly faster than the rest of the years, not to mention it was mechanic owned in detroit for 90k of its miles, so i don't know if it was 100% stock or not when i finally it. I just dont have the power feel i normally do. For example, if i run it hard while its still in an open loop, it will feel a whole lot more powerful than once it reaches normal operating temperature (185-195). I'm not trying to tune it yet btw, by unlocking the sct, i've had a code because the secondary air pump is disconnected and i'd honestly feel better having no check engine light for the first time i've owned the car lol.

I also have not done oxygen sensors, just because i expect a code to be thrown when they're needed, but i might as well do them now since i've done so much other work and not changed those. I have them sitting here, but was unsure if they were changed or not on my car before i got it, so i was waiting to see a code. I assume a vacuum leak just because with all the work that was done on my car, its hard to believe we didnt make any cracks ourself in the vacuum lines. I wanted to try propane just because i think maybe one of the lines which are wrapped up could have a crack inside. One of the reasons i have no problem throwing parts at this car, is so that i can keep records and if anything goes bad, it has a warranty again. If i was rich, i wouldnt buy a 2011 or 2012, i think i would just buy a crate motor and replace EVERYTHING just to have the only 96 with a full warranty lol.
 
Btw, everyones help is very much appreciated. 4 years ago I was mechanically retarded, now from having no choice but to do certain things myself i've learned 100% more than i ever thought i would know.
 
Have you try checking idle load percentages with the IAC valve unplugged at idle? Your complaints really do sound like a vacuum leak after the MAF sensor somewhere. Heck, the MAF sensor could be bad because if it's not reading the correct amount of air coming into the engine it's going to do screwy things. I recommend tearing apart your airbox and cleaning the MAF sensor with some brake cleaner on a Q tip. Then disconnect the battery for 30 minutes with your headlights on.
 
Will it idle with it unplugged if the iac is good? I remember on my 97, it would die if i unplugged it. And i did clean the maf with a maf cleaner, but no q-tip. At one point i also cleaned the throttle body but not hard, just very gently with a brush. I've also seafoamed the car probably on a monthly basis.
 
Unplug the IAC valve and the start the car. It "should" run off a base setting and idle up real high but I could be confusing myself. Haven't done it in a while. clean the MAF sensor softly with a q-tip.
 
NJaykaplan said:
It idles perfectly
Click to expand...

you discount good information far too quickly.

first you say your car idles at 80% load, then you say it idles perfectly.

There is no way in samuel hades that it is perfect if it's reporting 80% load.

The maf is a possible culprit for mis reporting load, irregardless if you sprayed it, qtipped it or unplugged it.

Now how does what happened on your 97 fit into this issue?
simply put, it doesn't.

If you expect people to assist you, stop discounting what they say with garbage replies like that.

notice the amount of replies? notice how they are drastically decreasing?
co-incidence? I think not.

Did you go buy that book?
it's a very well spent 24 dollars and based on your misconceptions...you probably should attempt to get some good information, and that book is a very very good start.

the book costs less than what you have spent on seafoam.
 
J said:
Unplug the IAC valve and the start the car. It "should" run off a base setting and idle up real high but I could be confusing myself. Haven't done it in a while. clean the MAF sensor softly with a q-tip.
Click to expand...

I missed this post, i have sprayed it a few times but always been too nervous to touch it (Maf) . I will grab a q-tip and clean it with the maf cleaner right now. I really have not touched the iac because i thought it would let a good amount of air in if it leaks, but i will start looking there too considering its got a good amount of miles AND how notorious they are. I do seafoam fairly often just because advance will have it on sale for 5.99 a bottle, and after cleaning the imrcs one time, i dont wanna ever have to do that again lol. But i just typed up a fairly long post about to come, and went back to reread the thread before i'm done just to try to see how i'm coming off dickish. Sorry again.

Edit: I will try unplugging the iac as well and checking the load, but i thought it would be very hard to get to, i will go look now. I was waiting until i can actually get it into my buddys shop, because where i live in south florida it is horrrrrible having to work outside. I guess i was not thinking the iac could leak only a little, that it would be very noticible if it was that. i still dont see how it looks like i'm discounting peoples replys, i do appreciate everyone.
 
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XLRVIII said:
you discount good information far too quickly.

first you say your car idles at 80% load, then you say it idles perfectly.

There is no way in samuel hades that it is perfect if it's reporting 80% load.

The maf is a possible culprit for mis reporting load, irregardless if you sprayed it, qtipped it or unplugged it.

Now how does what happened on your 97 fit into this issue?
simply put, it doesn't.

If you expect people to assist you, stop discounting what they say with garbage replies like that.

notice the amount of replies? notice how they are drastically decreasing?
co-incidence? I think not.

Did you go buy that book?
it's a very well spent 24 dollars and based on your misconceptions...you probably should attempt to get some good information, and that book is a very very good start.

the book costs less than what you have spent on seafoam.
Click to expand...

I mentioned the 97 asking about the iac and what is normal to happen if its unplugged. I'm not discounting anyones replys, i actually did miss something in J's reply about a spark plug wire could cause an issue but i thought that would be more noticible. I will change the wires just because i have some new acdelcos. Also, the O2s I have are motorcraft, but thank you very much for the info on bosch. The original owner did some work, but i know they were cheap as hell so i will definitely change them with the motorcraft i have, i wouldnt be suprised if it was some discount ones in there right now. I guess i should have been specific, but i dont see how i'm aggrivating you. I did see one time when i was talking about my fuel pressure under load, where i didnt seem to mention i was checking with a fuel pressure guage and not just looking at the stft and ltft. I definitely needed a fuel pump, was not just throwing that at the car, and when the car finally did idle funky the last few days before the fuel pump job, the pressure was at 28 after some driving, 32 when i cranked it (Both with vac). That is why i didnt go for the iac, i knew from other things it definitely needed a pump, and with 140k miles if i had to change the iac too i was willing to do that. It idles perfectly smooth and quiet, no misfires according to the engine light and the sct livelink. I had a high load % before the fuel pump job, and i thought that would be the cause, but it is still a little high. It is 60-80% at idle, but if i sit there and rev to 3k rpms, it will drop to inbetween 20 and 30. After pulling the ground and letting it sit over night, It does seem much more responsive now today. Still a high load %, but maybe the maf isnt reading right, it wont be very hard for me to go grab one at the junkyard and see if it makes any difference. I've recently cleaned not only the maf but the wires as well but not with a q-tip.

I guess my next step will be swapping a maf to see if the readings are any noticibly different if cleaning doesnt help, and i will also do plugs and wires. I have the wires that came with the car because they were changed at 90k miles, but its at 141k and change now, and currently champion rs12yc copper plugs gapped to 48 each. It has no misfires and idles quietly, as i said, it just shows a high load % and the tps % looks to be normal too as long as 20% is normal at idle. Really if this doesnt work, i'll give up for a while, it does drive nice i just think i could be getting better gas mileage.

Sorry if i came off like i was discounting anyones reply, but i felt like if i did change the iac i would be throwing parts at it. If its something easy to get to, and cheap, i dont mind. But my cost on an iac is probably 60-80 dollars and it seems like a real nice spot to get to. I am only being anal about the car because my first mark was amazing, my last one i got ripped off on, and this one i don't care how much it costs me, i want it to drive perfect.
 
It was pouring and i didnt get a chance to do anything, but i talked to my mechanic who told me to get my cat looked at. At WOT, he says the car gets a sulfur smell. Unfortunately my nose doesnt work, so smells and things like that i have no way to judge lol. As soon as i can get to a shop, i will change my upstream o2s. Old owner used the cheapest O2s rockauto has for the front and rear, i called and asked, and that was still over 40k miles ago.
 
First off, your mechanic is an ass. Ofcourse your car smells like sulfur, it's running super rich. That sulfur smell is your cat WORKING by burning off all that gas. Your cat is fine.

So I was reading over your post and I don't know why I didn't think about this in the first place. Your TPS sensor is faulty I'm sure of it. If your car is idling perfectly (which I understood when you said it because you meant mechanically, not entirely to include load %) than your MAF Sensor is fine. If the MAF was going bad the car would idle like CRAP. Your IAC valve is good too or the car wouldn't idle at all or it would idle super high. I do recommend changing it at the same time you change the TPS though.

Parts arent that expensive so I don't know where you're buying from. I shop on Amazon for my stuff and use RockAuto.com for part numbers.

TPS
http://www.amazon.com/s/ref=nb_sb_n...aps&field-keywords=Mark+Viii+throttle&x=0&y=0

IAC Valve
http://www.amazon.com/gp/gc/ref=topnav_giftcert

Don't mind XLRViii, he can get easily frustrated by unappreciated folks. I understood everything you were typing an just tried to give you correct info vs. assuming you didn't care.
 
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J said:
First off, your mechanic is an ass. Ofcourse your car smells like sulfur, it's running super rich. That sulfur smell is your cat WORKING by burning off all that gas. Your cat is fine.

So I was reading over your post and I don't know why I didn't think about this in the first place. Your TPS sensor is faulty I'm sure of it. If your car is idling perfectly (which I understood when you said it because you meant mechanically, not entirely to include load %) than your MAF Sensor is fine. If the MAF was going bad the car would idle like CRAP. Your IAC valve is good too or the car wouldn't idle at all or it would idle super high. I do recommend changing it at the same time you change the TPS though.

Parts arent that expensive so I don't know where you're buying from. I shop on Amazon for my stuff and use RockAuto.com for part numbers.

TPS
http://www.amazon.com/s/ref=nb_sb_n...aps&field-keywords=Mark+Viii+throttle&x=0&y=0

IAC Valve
http://www.amazon.com/gp/gc/ref=topnav_giftcert

Don't mind XLRViii, he can get easily frustrated by unappreciated folks. I understood everything you were typing an just tried to give you correct info vs. assuming you didn't care.
Click to expand...

Oh you don't even know, i love him and i've known him 7 years, but yeah he is. At idle, on my actron scanner, the tps % shows to be 20% and at WOT it goes to 95%, i have not really checked it much though. I have been using the little actron mainly because i had my car broken into recently and not trying to keep a nice laptop in there, nor the x2. I will try changing the tps and i will clean the maf with a q-tip and maf cleaner as soon as the weather and time allows. I always shop around for parts, or try to snatch up wholesale closeouts at rock-auto. I always assumed it was running lean vs rich because anytime i check my plugs, they're too light colored as well. TPS should be an easy change at least, i'll shop around. I wish advance had motorcraft, they're right across the street but i dont use them for electronics.

Edit: I will see if i can stall and get another paycheck before going into this job, that way i can afford a motorcraft iac and tps sensor. Off topic, but my windshield wipers only work on high, and don't retract, so i will swap the whole wiper housing since the bolts holding the motor to housing are destroyed anyway. Combining the jobs might work me a good amount of extra space in there.
 
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Haha! I guess I called it. ;)

Sounds like you have a good list in front of you, you seem to be on the right track, and you have a good understanding of everything we're throwing at you so I'm confident you'll figure it out.

As far as the TPS percentages vs. load at idle, you can always volt meter it so see if the readings are in spec before replacing it. I can find the figures and can link a walk through if you'd like.
 
I appreciate everybodys help, my current high priority plans are now the O2s and the TPS sensor. I will also try to get an iac if i can afford a motorcraft one, if not i will put it to the side. Even with the high load % she still idles at 600 rpms, and before i do the above i will change my wires just because i actually have 2 sets of wires here, one ac-delco and one taylor on rockauto which was sent to me by mistake instead of the acdelco and they never asked for it back (again from rock auto.) With how easy it is to do wires and plugs on these cars, i might change the plugs as well, i think they've been in about 10k miles lol. I honestly do like doing it to see how its running, but everytime i've seen them pretty white or light tan colored. I'll probably stay with the 2 ranges colder plugs considering i'm pretty hard on it, and whenever all the problems are taken care of, i will pay for a tune for my x2 :).

As far as the iac goes, now that i think about it, and with me HAVING to remove the windshield wiper assembly already, i guess its smart to just get them both out of the way so i never have to touch that assembly again on this car lol. I really do appreciate everyones help, i'll update and probably use sct for my datalogging this time.
 
Anytime. :)

I quickly buzzed over the thread and I don't think you mentioned the year of your car. I'm assuming its a Gen 1 based on the IAC location complaints. :) My suggestion....get a 1/4 deep wobble for that IAC bolt with the stupid post on it. Lame...still by far the worst job I've ever done on a Mark, and that includes the oil filter adapter gasket I did immediatly afterwards, lol.
 
a 96. Lol. First thing i had to do was hunt down imrcs when i bought this thing. I do love it though, first gen with obd 2.
 
I keep looking up O2s because i was curious who makes Motorcraft for Ford and all i have found is old threads saying Bosch used to make them, and even some threads that had O2s with both ford and bosch stamped on it. I'm now curious, yes off topic to my thread, but xlrviii was talking about them switching much slower. I'm going to search more on the forum about that, but i thought most of the time bosch was quality stuff. I don't know if you are still checking up here, maybe i'll shoot you a PM if you don't come back, but were you perhaps talking about universal o2s from bosch? Just curious for future references.
 
I've never had problems with Bosch but then again I don't have a data logger to look at the switching intervals.
 
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