Driveability issues with the CVPI

[Eric91Z]

OK, so there were some comments made on how my car is running in the JLT intake thread on CV.net after I posted the video up.

So I am looking for thoughts and input on this. I know this type of thing is next to impossible to try and diagnois over the internet, but I am hoping to use this as a starting point as there is basically no tuner options close by.

Anyway, here is some background:

- The car is an '03 CVPI that was used for city duty. I purchased the car with 107,000 miles on it. The car felt like a dog from day one. Got on it to WOT the first night I had it and got check engine lights. As posted on here previously they were a mis-fire on #5, cat out of range, and the P1000 (I think).

- So, did new Motorcraft plugs, cleaned the stock MAF (with CDC MAF cleaner), new air filter, and new fuel filter. Car was MUCH better - except for the sucky stock shifting. But has always had that "hunting" sound/feel in the rpms after the 1-2 shift (you can hear this some in the video). I continued to get the cat-out-range CEL after doing the above, but no more mis-fire or anything.

- Couple months after getting the car did the Marauder air box, Marauder 80mm MAF, '04 Zip Tube, and 89 octane tune on XCal2 from Lonnie. The tune also shut off the second set of O2 sensors and no more CEL for the cat-out-range since then. Still had the issue in rpms after the 1-2 shift. If you kept at WOT it would "hunt" on the rpms (TC locking/unlocking ?), but if you let out of WOT just a tab it would wind up nicely

- Last weekend installed the "custom" JLT CAI. Car seems to run smoother overall, part throttle response seems much better, but issue after the 1-2 shift is still there as it always has been - now just more pronounced due to the intake noise of the CAI. And some commented that the car seems to be slow to rev up under load. (FYI - I do have the winter tires on still and the rears are taller than the stock tire size and I believe the car has 3.27 gears).

So, take a listen to this video and let me know what you think. Hopefully the weather will be good this weekend so I can get better, more defined footage and some data logging with the XCal2.

But in the video there are 4 different "runs":

1) First one is getting on the interstate and not going WOT until around 40mph

2) WOT from a stop up to about 50mph (started letting off the gas around 50mph)

3) WOT 25-45/50 mph short run

4) WOT from about 55 mph - you can hear the revs fluctuate some in this during acceleration

(please ignore the brief bit of my daughter at the end of the clip as I didn't get that cut off)

http://www.youtube.com/watch?v=1beMPxRXFz4




I will post up new video as soon as I get it and then anything I can post from the data logging, too. But in the mean time would love to hear any input on things to check or thoughts of what might be causing this.

As I noted above, some people stated in the other thread that the car seems to "sound slow" and that it is "bogging". The car has never felt as "peppy" or responsive as my sister's '01 CVPI with 150,000 highway miles on it as opposed to mine with now 116,000 mostly city miles on it.

But other than the WOT issues above, the car starts and idles great, runs smoothly with no bucking or anything, no current CEL's, does not burn or leak any fluids (now that the oil cooler adapter issue is resolved), and gas mileage has been steady with 16-18 on average in town and usually low-to-mid 20's on the highway.

[Aren Jay]

So what is your question?

[Eric91Z]

Just looking for input or thoughts on possible issues or what to check or what might be causing the issue.

[Raudermaster]

That sounds odd, almost like the car is being held back, and the tranny definately sounds off. There was a very old video back on CVN of a member...White something, believe he was over in India and he had a white Town Car, he had a similar video and right around 50mph or so, the car would sound really odd, and then it would shift.

[magindat]

Cats plugged up? Doesn't answer the trans question, but does answer the 'sluggish' question.

[Breadfan]

Cats plugged up? Doesn't answer the trans question, but does answer the 'sluggish' question.

My thought as well. It can also impact trans performance if the PCM is having troulbe figuring out what the engine is doing due to poor performance from a clogged cat. I've seen cars hunt for gears due to clogged cats before.

[Eric91Z]

Cats plugged up? Doesn't answer the trans question, but does answer the 'sluggish' question.

Do you think that is a real possibility in regards to cause of the issue? Because I wouldn't doubt if I have at least 1 bad cat out of the 4 from the oiginal mis-fire issue. That was the recuring CEL I was getting after fixing the mis-fire. It was a Bank 2 cat out of range which would make sense since that is the side the #5 mis-fire was on. Maybe loaded with fuel and ruined the cat?

I was thinking of doing the Magnaflow OEM replacement cat-pipes with new O2 sensors along with new mufflers and tips this spring, but kept putting off since the over all cost of all of that would be close to $1000. But if it would help I would do it for sure. I wish the car had fewer miles so that it could have been covered under the emissions warranty...

Any way to determine that from the data logging? I know that with the tranny or shifting issue that after the 1-2 shift at WOT it will bog some. But if you let out of WOT a little it will pick up and eventually pull quite well - at times.

Like I said, it definitely doesn't feel as "peppy" as my sisters '01 with 150,000 miles and definitely not what I remember after driving a few '92 and '93 models when they were originally released back in the day.

Keep the ideas coming. I am open to any and all input and discussion.

[UncleLar]

It's probably all pigged up and carboned up.I'll bet the old plugs were full of deposits.
Lots of guys here seem to recommending Sea Foam treatment in the gas tank and thru the pcv hose to the intake to clean it out.

[Eric91Z]

It's probably all pigged up and carboned up.I'll bet the old plugs were full of deposits.
Lots of guys here seem to recommending Sea Foam treatment in the gas tank and thru the pcv hose to the intake to clean it out.

I have done the SeaFoam through the PCV hose and did get some smoke out of it. Did not change the plugs afterwards, but they were relatively new before (within 1000 miles). I have heard both you should change and OK not to change.

[252life]

Do a Engine Compression Test, it's a good start to diagnose the engine problems.
It definitely sounds slow in the video.

[JMan]

Cats plugged up? Doesn't answer the trans question, but does answer the 'sluggish' question.

Well, see below!


My thought as well. It can also impact trans performance if the PCM is having troulbe figuring out what the engine is doing due to poor performance from a clogged cat. I've seen cars hunt for gears due to clogged cats before.

I concur! Could very well be the culprit.


Do you think that is a real possibility in regards to cause of the issue?
Keep the ideas coming. I am open to any and all input and discussion.

Do you have a vacuum gauge of some sort or can you borrow one? Unfortunately, multiple different problems can have the same symptoms. A vacuum gauge of some sort will help.

Take a reading from one of the ports on the intake elbow. A strong 2v 4.6l should pull around 20"hg at idle when warm. Next take a reading at ~1500rpm and at ~2500 rpm allowing the engine speed to equalize at each increment. Whatever the reading at idle (Whether 15" or 22", doesn't matter), it should increase at each increment. It doesn't need to increase tremendously, but it should increase! e.g. Idle 19"hg, 1500rpm 21"hg, 2500rpm 22"hg. Faulty cats causing blockage would present lower readings at higher rpm's once the speed is stabilized. This does not work on cars with blowers!!!

I agree, car sounds wimpy for a PI and the shift points and lock-up schedule really sound like they need some correction. But you need it to run right before making those assumptions or corrections.

Best luck,

J

[Raudermaster]

How does he do that with no tach? :D

[Eric91Z]

I think the Live Link SCT software will show engine rpm. Planning on getting the XCal2 hooked up to the car and laptop this weekend and get some data logging done (as long as we don't get too much snow that they are predicting!).

Will then look to see if I need to get a vacuum gauge or if one of my friends has one I can borrow to do the above testing.

[JMan]

How does he do that with no tach? :D

This symbol [~] means approximately. The idea, for the black and white crowd, is the engine vacuum (read: efficiency) should increase above idle and up to a given engine speed (typically near peak torque.). If you guessed and did 2000 and 4000rpm, it would still hold true as long as both were above the idle reading after the speed and vacuum equalized. As I stated, faulty catalysts, blocking exhaust flow, would present lower readings at the higher increments.

Best luck Eric,

J

[Eric91Z]

OK, so got 3 data log runs done with the current setup. Ran out of time to switch intake and tune as I spent a while configuring and getting it to recognize the device.

Anyway, now what I would I do. And how to determine if I got the correct parameters checked? I have RPM, IAT, knock sensor 1, MAF counts, upstream O2 Voltage 1 & 2, LTFT 1 & 2, STFT 1 & 2, MAP, O2 Voltage Front Bank 1 & 2, TC slip, Knock Sensor 1.

I think that was it from what I can read off the graph. Now, how to read?