***car bogs on start up -> Still doing it...NEED help/ide

Jerome Adams · Post by **Jerome Adams** » Tue Jul 26, 2011 9:13 pm

***Title edited to capture entire saga***

My car started bogging real bad on start up and had erratic idle (much worse with A/C on). I had oil in the #4 spark plug tube, so last night pulled VC and pulled the spark plug tube, cleaned, and hammered back in after putting on some blue thread-locker. I also replaced the VC gasket and spark plug seals. This morning it ran great and no oil in the #4. No problems on the way home and then about an hour later when I went to take my kid to Taekwondo the car bogged a bit and acted stupid. When I got there I pulled the #4 plug wire and no oil, so I thought it was a fluke.

Went to leave 45 min later and it took me 3-4 min just to get out of the parking lot...then a few minutes later it was fine.

Only code is P0038 and I have had that for a long time...I have a LTH with the downstream O2 in front of the cat.

2-3 weeks ago, I did a mag head, comp 400, and mag intake mani install and have run the car for over 1000 miles since and this is just now starting. I dont think it is related to the install, as the car ran okay for weeks (got me to Wisconsin and back and numerous trips around time and many, many trips up to redline).

Any ideas??? I use Lucas fuel treatment a couple times a year, and the plugs looked good when they were out last night. Plug wires are new within the year. Car has 106K on it and I flog it regularly

Kelevra · Post by **Kelevra** » Tue Jul 26, 2011 9:23 pm

ever change the coil pack?

Jerome Adams · Post by **Jerome Adams** » Tue Jul 26, 2011 9:42 pm

no stock coil...but if it is the coil, why would it only run like crap on start-up? I also thought fuel filter, but same thing, you would assume it would have a hard time keeping up under load but once the car is warmed up it pulls pretty decent. There might be a slight stumble, but I have done so much in the last 3 weeks I am still learning the new feel of the car.

Kelevra · Post by **Kelevra** » Tue Jul 26, 2011 9:50 pm

does it only do it at idle? or under power as well?

Jerome Adams · Post by **Jerome Adams** » Tue Jul 26, 2011 10:16 pm

both. It will idle like crap falling to 500 rpms and stumbling before coming back up. Feathering the accelerator will sometimes help, other times it will bog worse (acts like it is flooded). Even if I do get it to rev it seems to choke around 4k rpms until it warms up.

The idle had been erratic due to the install but then it all evened out for awhile. It barely had any lope at all if I had the AC off, but if I turned the AC on during start-up/warm up...it had really strong lope (sounded badass!) Once it was warm the lope would almost completely go away. Then a few days ago it started stumbling real bad for the first few minutes, especially under load (trying to go up hill). I figured oil on the #4 plug was needing to burn off and then it would be fine...but there is no more oil and it is doing the same thing.

Oil on the dipstick looked fine...oil change after install a few weeks and a little over 1K miles ago. (mobile 1 5w-30)

No evident leaks (oil or vacuum)

Kelevra · Post by **Kelevra** » Tue Jul 26, 2011 10:48 pm

IAC going bad?

Jerome Adams · Post by **Jerome Adams** » Tue Jul 26, 2011 11:13 pm

will look at it tomorrow and try to clean it up...

sirvaliant_98 · Post by **sirvaliant_98** » Wed Jul 27, 2011 5:04 am

Yeah I was going to guess iac also. Kinda what it sounds like to me. Unplug it before you start the car and see what it does. I had similar issues with my car, I unplugged the iac and issue went away

Jerome Adams · Post by **Jerome Adams** » Wed Jul 27, 2011 1:35 pm

It works fine in the AM or if the car has sit for awhile (coming home for lunch). It only seems to do it, if the car sits for about an hour or so and then go to restart. It has to be a sensor of some sort.

I know the new magnum intake mani gets smokin hot compared to the old plastic one. Like I said the swap was a few weeks ago, so I dont think this is swap related...but not ruling anything out. Hope to have time to mess with it tonight.

Post by **occasional demons** » Wed Jul 27, 2011 3:16 pm

Use a meter and back probe your TPS sensor, remove it if needed, and check the output voltage. Brown/Yellow (middle) and Orange/Dark Blue wire.

If the voltage is too high for off idle, it will try to flood the engine. It is relying solely on the o2 to lean it out at that point.

It is kind of how mine was a few weeks ago. It was reading 3+ volts from 3/4 throttle down. It would idle decent tho, just as soon as you hit the throttle, it would stumble and lope radically. Once the throttle was opened enough to match the voltage, it would come on like a bomb, and throw you back in the seat.

It was a random thing, until it got to the point it stuck in that range. No TPS code, as the voltage was within the window. I did get a TPS/MAP correlation at the end. An opposite one from the NGC 60mm: The MAP was showing too much vacuum for the "throttle opening".

Jerome Adams · Post by **Jerome Adams** » Wed Jul 27, 2011 10:39 pm

It didn't act up today at all. I know even less about electronics than I do engines...but I will see what I can figure out this weekend. I have a cheap $20 wiring kit/box from Autozone that has a bunch of connectors, cheap needle-nose, and the little probe thingie, but it only has a + and - light on it. So I am assuming I will need something more fancier. The auto hobby shop should have what I need. In the meantime I can practice some "GoogleFu" and see what I can learn about car electronics.

For other peoples with comp 400 or larger, is it normal for the cam lope to increase dramatically when the AC gets turned on. Mine goes from a slightly off (most people wouldn't identify it as lope, just think it was a POS neon that was on its last leg) to holy shit, does that thing have a V8...I prefer the latter, but if given the choice would prefer my car to run and pull strong, than sound bad ass and stumble.

Jerome Adams · Post by **Jerome Adams** » Thu Jul 28, 2011 12:06 am

The more I read, the more it sounds like a bad TPS. The car will also sometimes hit "dead spots" around 2-3K rpm, stumble for a bit, and then take off. That has been going on for a long time, but not frequently or steady enough for me to diagnose/worry about.

A little google action returns prices on TPS from about $25-$100+...most made by "Standard". I will probably order one from Rockauto as they are cheap and ship super fast....unless I get a suggestion otherwise.

Post by **occasional demons** » Thu Jul 28, 2011 8:27 am

Yeah, I would have gone with RA, if It wasn't so bad that I didn't want to drive it like that for a few days.

I got one from AZ for $50. I have to admit, it doesn't quite match oem quality, as the speed control is now not as consistent as it was. But for the price difference, I guess I'll just have to deal. Otherwise, I prolly wouldn't have noticed any difference.

Also to note: The Speed Control will not set with a CEL lit. At least anything fuel control related.

Jerome Adams · Post by **Jerome Adams** » Thu Jul 28, 2011 8:28 pm

occasional demons wrote:

Also to note: The Speed Control will not set with a CEL lit. At least anything fuel control related.

Can you elaborate on that? I always have at least one code...usually P0038 and P0551.

Does that mean my car is staying in closed loop?

Post by **occasional demons** » Thu Jul 28, 2011 10:52 pm

I think if it is only in relation to the TPS, and/or MAP. It needs to know where the throttle/engine load is to control the speed. When I finally got P0121*, the cruise control would not set.

I have multiple codes due to having an R/T PCM in a non R/T car, in addition to the PCM being SKIM equipped, and somehow failing to lock down. But none of those will set a CEL, and seem to have no affects.

*(M) TPS Voltage Does Not Agree With MAP TPS signal does not correlate to MAP sensor signal.

Jerome Adams · Post by **Jerome Adams** » Fri Jul 29, 2011 8:31 pm

Gotchya...speed control = cruise control (which I dont have). I thought that is what you were trying to say but somebody (non-neon person) was telling me any cel will put the car into closed loop mode and you lose hp and mpg...I didn't think that was the case....but wanted to make sure that isn't what you were hinting at.

Car bogged for a second or 2 leaving the grocery store today so I may just get the TPS and see if that fixes it instead of wait for things to get worse.

edit: Just ordered a Standard Motor Products TPS (TH213) for $26.77 shipped from Rock Auto (using the discount code provided in the Timing Belt thread).

Be even happier if it solves the issue, and I think it will, otherwise I wouldn't have ordered it.

Jerome Adams · Post by **Jerome Adams** » Sat Aug 06, 2011 8:32 pm

Car acted stupid again trying to leave the mall. Bogs and wants to die, throttle input does nothing...spits and sputters. If I can get it to rev to about 3-4K I try to slip the clutch and get moving and it just bogs, lurches, and tried to die until I clutch in and work the throttle until I can get the revs back up...after a few minutes of warming up it worked okay and got us home.

So I just swapped in a new TPS and removed the IAC and cleaned out the backside of the throttle body. Took the CAI intake off and cleaned/adjusted that too. (Side note- if you are going to do a mag intake swap, makes sure you port out the opening that connects to the Throttle Body as much as possible...it steps down pretty far, restricting all that nice air you are trying to get).

Hopefully that solved it. If not, I will be swapping the IAC next. And if that doesn't work, maybe a new coil... maybe a new coil anyway, it is the original and has 106K plus hard miles on it.

Post by **occasional demons** » Mon Aug 08, 2011 7:20 am

If you have a hand vacuum pump, you could check the output of the MAP sensor also. But I don't think the problem would be as random with that. There are no moving parts to wear, it would be either good or bad.

With the coil, heat might affect it. IDK, I have over 160,000 on mine, and it is doing fine. The Accel coil I bought only lasted about 5000 miles. OEM FTW!

Jerome Adams · Post by **Jerome Adams** » Mon Aug 08, 2011 1:41 pm

Well I ordered a Granatelli coil from MP and it is on the way. Today on the way home for lunch it wouldn't rev past 3500, I pulled over and checked the codes and had:

P0068-MANIFOLD PRESSURE/THROTTLE POSITION CORRELATION

then I restarted it and it worked fine? Will look into replacing the MAP next

Post by **occasional demons** » Mon Aug 08, 2011 3:06 pm

Either a bad TPS/MAP or moderate to large vacuum leak will give you that.

And of course a larger TB is a potential cause on '03 up. But I doubt at idle a TB would trigger it.

Jerome Adams · Post by **Jerome Adams** » Mon Aug 08, 2011 9:31 pm

I have had the MPx 60mm for years and never had an issue.

I just reset the comp tonight so I will see if it comes back. If it does I will order the MAP.

Post by **occasional demons** » Mon Aug 08, 2011 9:58 pm

Yep I have the Mustang 60mm TB, and got that code with the faulty TPS reading too high at idle. At first I was like

it's not NGC! Uh-oh!

But like I said, at idle, I doubt the airflow/manifold vacuum would set that code, unless either the MAP sensor, or TPS is not sending the correct info. Each time I checked the MAP, it was spot on. The TPS finally got to where it wouldn't read below 3ish volts, thus the correlation code. Manifold vacuum was too high of a value for the throttle being "open" (in the pcm's view) that far.

Pull the MAP and check for debris/goo blocking the inlet. If it is closed off enough, it could affect the response time. MAP sensors are not cheap, (unless you go to the JY) so hopefully it is a simple fix.

Jerome Adams · Post by **Jerome Adams** » Tue Aug 09, 2011 8:57 pm

Well it acted up again so I pulled off the new TPS and put the old one back on, then I pulled the MAP and cleaned it out and reinstalled...no change. It runs fine for a bit and then wont rev past 3500...then even at steady throttle it is like it just cuts out and I don't move my foot and then it takes off and cuts out.

I just ordered a new MAP from Rock Auto for less than $15 shipped.

STANDARD MOTOR PRODUCTS Part # AS221 $10.81

If this doesn't fix it...then I will have to check the wiring to both the TPS and MAP.

One thing about the Magnum intake is that the MTV doesn't make the MAP a little harder to get at!

Post by **jonnymopar** » Wed Aug 10, 2011 8:35 pm

Jerome Adams wrote:If this doesn't fix it...then I will have to check the wiring to both the TPS and MAP.

Do this! Bad wiring to the TPS is so common, there's actually a Chrysler part number for the repair kit. It happened on my 03. Try starting the car, then with the car running and idling, go under the hood and wiggle the TPS wiring around. When mine did that, I'd go from anywhere between 400rpm and 1600rpm. Spliced on a new connector and it's been good since.

Jerome Adams · Post by **Jerome Adams** » Thu Aug 11, 2011 7:42 pm

I am actually going to try and take the connector apart and look at it. I have the MSD 8969 so I can sit and watch the digital tach reading jump all over the place but the idle doesn't change. Reading will jump from 0 up to 3500 and then bounce all over. It is likes to do it in intervals of 800 rpms (0800, 1600, 2400, 3200 etc).

I saw it was a common problem on the SRTs and they have the repair kit for them, but I haven't seen the repair kit for the 2.0L.

Post by **occasional demons** » Thu Aug 11, 2011 8:32 pm

I don't think a bad TPS will affect the tach signal. Have you tried unhooking the 8969, to see if it is the problem ?

Jerome Adams · Post by **Jerome Adams** » Fri Aug 12, 2011 8:21 pm

Well, I swapped out the connector and that didn't fix it. Going to put in the new MAP and see if that solves it.

Then I will unhook the 8969 and see if that is the problem...maybe my crappy wire job is coming undone somewhere...

Jerome Adams · Post by **Jerome Adams** » Fri Aug 12, 2011 11:18 pm

So, I got the new MAP on and took it for a test drive and it worked fine. Then I put the new coil on and took it back out and flogged on it some more just to make sure and it started acting up again. (Didn't want to rev past 2.5K-3.5K...it changes) and the P0068 is back.

I double checked all the wires I had going from the 8969 to the coil pack harness.

The 8969 still jumps around and I am not sure if the 2 issues are related.

My next theories:

The computer needs to relearn everything so I will reset it and try again (for some odd reason turning the car off briefly seems to help me be able to rev past the sticking point for awhile, until it decides to start acting up again).

The P0068 problem that the 03 R/T have with the 60MM TB. Maybe I didn't get the code because I had the shitty plastic intake and that was enough of a bottle neck to prevent the code. I always assumed it was the R/T PCM vs the SXT PCM...but maybe the codes aren't that different and it is the intake and the 60mm that don't jive. But if that is the case, why did my car run fine for over 1000 miles after the intake was installed with the 60mm TB?

It ran fine for a few weeks after I hooked up the butterflies. Then it wouldn't idle for shit, but once it warmed up it was fine. Maybe it is the butterflies activating that cause the issues? I dont have them set to a WOT switch...just open at 5K and close at 7K

Now the idle problem is gone but I get the fake limiter/limp mode.

So I am going reset the comp again and try again tomorrow and hope it is miraculously better. If the code comes back, I am going to swap the stock TB on...and I am almost hoping that doesn't fix it, because I like my 60mm TB.

And I still don't know why my 8969 will jump all over the place.

I just want my car to pull like a train, get 30 mpg, and be as reliable as a swiss watch...is that too much to ask???

My other theories are a bad ground somewhere or my PCM is going bad....I hope it isn't the PCM

Jerome Adams · Post by **Jerome Adams** » Sat Aug 13, 2011 2:03 pm

this morning I adjusted the CAI again hoping I could make it stop throwing the dreaded P0068 but to no avail.

It seemed to have issues when I went off throttle going around 50mph in 4th on a slight downhill...so that seems to be where the MAP and TPS disconnect comes. It is probably pulling too much vacuum at that point? Once I get it to start acting up, it will buck and lurch and act like an ass until I shut the car off and start it back up and then it will pull all the way to redline and be fine for a bit before I hit another window where the TPS and MAP go out of whack.

I was also able to get it to act up going up a hill in 3rd at about 2.5K rpm. If I avoid these windows the car seems "fixed".

So I took off my beautiful MPx 60mm TB and busted out the tiny, ugly ass plastic stock TB and put it on and no lurching, no bucking, and no codes. I guess I will have to recalibrate my right foot for the less sensitive TB and just get used to having a little less response.

I was really hoping it wouldn't be the 60mm because I ran it for years with no issues, but when I upgraded to the mag intake mani, the mag head, and a comp 400 I guess it put the air flow outside of the acceptable parameters.

I am going to make sure the code doesn't come back, and then in a month or 2 I may end up selling my beautiful 60mm TB

I also have a new TPS that I didn't need, 2 different TPS pigtails I didn't need, a MAP I probably didn't need and a new Granatelli coil that I probably didn't need either. So over $100 and 2 weeks or so of troubleshoot, when the part I needed all along was sitting right there on my workbench

Hopefully this is my last entry in this diary...

Danteneon · Post by **Danteneon** » Sat Aug 13, 2011 2:59 pm

Ouch. Sorry to hear that you have to go back to a stock TB. But if it gives you less headaches, the loss of throttle response is a fair trade.