Kisara

iTrader: (1)

I have searched for all of this, but nothing has helped so far… But there are still things I found in my searching that I have yet to try. I just want to see if there's one thing in particular I should look at. Need some input and inspiration. (S4 TURBO)
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My problems started around when I had a stereo system installed. They might’ve grounded something that shouldn’t be grounded while installing it, but I don’t know. The problem has gotten progressively worse. My problem is a violent bucking/hesitation on acceleration, sometimes accompanied by a bad idle, which sometimes dips too low and the engine dies. In the past, it’s only happened when the car is fully warmed up, but now it’s started to happen all the time. I have replaced and adjusted the TPS—didn’t help. Spark plugs and wires were replaced ~1000 miles ago. Replaced fuel filter. I checked for vacuum leaks, and didn’t find any (but I’m going to check again soon when I have help). I regrounded the main battery ground, and the one under the trailing coil (haven’t done the one under the UIM yet). I do have a hesitation at 3800 RPM, so I do need to check that ground. I have not checked the injectors yet, either.
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Recently the problem has gotten a lot worse. I have turned the key to start the car, and nothing happens (I hear something buzzing, but it won’t crank). Eventually, the car does decide to start. But then it dies, after sitting at 2500 RPM for a second. My accelerated warm-up doesn’t work anymore. I have to give it gas to keep it alive (vacuum leak?). Then the idle is really random, going up and down between 1K and 500 RPM. It’s not cyclical. It might go from 1K to 800, back to 1K, down to 500, up to 900, etc. Very rocky, you could say. The other day, I found a large hose from the AFM to something on the engine (I can’t see. Throttle body, I guess) that wasn’t connected. I connected it, and it seemed to get rid of some hesitation, but not all of it all the time (I haven’t tightened it on there well, though). Still runs really roughly sometimes, and it was after I connected it that my accelerated warm-up stopped working.
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Oh yeah, and my idiot lights have never all come on whenever I start turn the key to ‘on.’ They work when I have a problem, like low coolant, or if a door is open, but not when I turn the car on. At one point, they would all turn on if the car stalled itself (engine dying due to that stupid idle if I put the clutch in or something), but not anymore. The clock worked occasionally when all the lights would come on if it stalled, but now it works all the time. The A/C and fan work only when they want to. And if I turn them on, it tends to be instant death to the engine. Sounds like maybe the BAC.
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The car does run rich (judging from the brown stains on the rear bumper), so I’m pretty sure it’s not leaning out. The hesitation is sometimes REALLY violent (it hurts, honestly), but other times it’s just lack of any power/acceleration. It lasts for maybe a minute and goes away. But then sometimes comes back. Maybe it's flooding itself. I’ve tried pulling codes, but have nothing. I’m pretty sure the AFM is connected correctly. The engine is a fairly new rebuild, probably with 3000 miles on it. The vacuum hoses all look pretty new and in good condition, and that’s why I haven’t looked at them again yet. I’m confused. I’d really like to get my car running well again by late July. Help?? Things I should DEFINITELY do?


Sorry for the length... Just wanted to be detailed.

Malevolent5

You need to find out who rebuilt your motor and did the install and talk to them. Also, no matter how nice the vaccum lines look, check out the fsm and make sure they are all firmly connected where they belong. The AFM hose you mentioned needs to be securely fastened as well, that alone can cause half the problems you've mentioned. Good luck!!!

RotaryRocket88

iTrader: (7)

It sounds like you have a horrible vacuum leak somewhere along the intake manifold. Get a can of something like brake clean and spray it around gaskets and vac lines while the car is running. Idle speed increases will tell you that there is a leak where you just sprayed. It's going to be harder with the TII's intercooler blocking things, but you can rig up some PVC pipes to connect the turbo to the TB while you're testing things out.

Kisara

iTrader: (1)

I actually did talk to the guy who did the rebuild a couple months ago, and he said it was probably the TPS or AFM... I thought about taking the car back to him and making him fix it, but I really want to do it myself. Heh.

Thanks. I'll get out to the garage sometime this morning and look for some vacuum leaks again. Will it be a noticeable/large increase in RPM when I spray around a vac. leak? I have to listen for it b/c I don't have someone to watch the tachometer right now...

trust7

Ok heres a thought:

and this is just something that all people working on cars should perscribe to:

REMOVE THE LAST ITEM YOU JUST DID OR HAD DONE BEFORE TOUCHING ANYTHING ELSE!

My grandfather was an engineer for Mobil racing and his "catch" phrase was "its probably the simplest thing" and honestly it usually is the simplest thing, we just are too stubborn to admit or realize this.


1. Remove or unplug every single item of stereo equipment that was installed.
2. Check every wire or plug, hole they drilled every SINGLE thing they touched in relation to installing the stereo and make sure there are not any wires grounded, crimped, CUT ?, or damaged in any way.
3. Also just as an FYI it is quite possible something was damaged in relation to either the wiring or internally on the ECU, do you have a friend who will loan you his ecu for testing ? If you do then assure him you will check your wiring related to this stereo **** PROFUSELY before plugging in his ecu, because you might owe him an ECU if you dont' lolz.

After all that if you have thoroughly checked x 2 your wires and stereo crap related to this and still have this problem then and only then should you check in this order:

1. Grounding, make sure if you had the 3800 buck which is the transition from Primary to Secondary injectors by the way, that you make sure your engine to chassis and ecu/plate to chassis and all grounds are good to go.

2. double triple check all your vacuum lines for leakes and holes and loss of connections. I bought a T2 a month ago stated not running would idle and die over and over for 1500.00 was only a boost pressure sensor vacuum line T'd off from the manifold for N370 pressure sensor and the boost gauge, at the manifold the hose was broken, thats it, runs like a scalded ape now (new motor and all lol)

C

Kisara

iTrader: (1)

Hm... I thought of another question. Could a bad/not-good-enough battery cause problems? The battery I have was put in (by the previous owner) June '07. It's an Autocraft Silver. From what I've seen, those are pretty cheap (I'm no battery expert, though). Maybe the stereo system is putting too much of a load on it..?
Batt. is currently being charged, b/c I tried to start the car a little while ago, and it cranked scary slow (the starter is fine.). It died last week after I accidentally left the parking lights on for a few days. grr. So I charged it for a while, cranked slowly, but ran. Though crappily at times.
Electricity confuses me.

lax-rotor

iTrader: (1)

Then there's really no reason to say that. You're on the right track with that. Check and clean your grounds, and if it still doesn't fix your problems check your injectors or send them out to be cleaned. KGParts did mine when I had extremely clogged ones.
Are you sure it connects to the AFM? I do not remember there ever being a hose of any sort connected to the AFM... the intake pipe sure... but not the AFM You may have your idle set much too low. Have you messed with your secondary throttle plates at all? If you have may I suggest you return them to normal and adjust the idle properly. (You may have to adjust the idle so it runs higher on the tach than normal. Wait for the engine to heat up to operating temperatures and then set it. Osilating idles usually indicate a TPS out of spec (whether that's incorrectly set or if it's dying/dead I do not know. It's usually good practice to replace it with a brand new one, or remove it--but that will cause the computer to think you're WOT all the time)
You have a short somewhere. I'd recommend taking out a multimeter and seeing where you're completing the circuit prematurely. You may also want to re-solder your idiot cluster, and may have to do the same with your logicon.
sounds really similar to clogged injectors. Possible vac leak, but that's really easy to check. Given that information I'd recommend the following:

0) Check your TPS, and other electronics to make sure they are within spec and contain no dead spots. That would by far be your easiest option up front. Another easy check is to remove the TPS completely and see if the problem persists. Also adjust your Idle. It honestly sounds like you have it set too low and you BAC is having trouble trying to maintain it.

1) Check your fuel pressure (go out and get a fuel pressure gauge and check it while driving around to see what your fuel is doing when you have only your primaries running, and then both primaries and secondaries. This will tell you if you're actually getting the fuel you're supposed to be.

2) Check your vac lines using the propane method. Searching for that should tell you alot of things.

3) Not being able to crank may be as simple as coroded terminals on the starter/battery or may be as severe as a slow drain on the battery or even a failing battery. Which I am currently suffering from. I'll probably trade it all out when I move the battery to the cabin.

If you have any other details that may help us diagnoise your faults with the car. Also making a descriptive title will generate more attention than a "help me" title. For instance: "Hesitation/bucking, and other electrical problems" would probably yeild much more help than what the current title is. Just FYI.