Chasing power loss

[bryno]

Quick history on my problem with '99 DII:

I installed a 4.6 w/ headers (no cats) and Piper cam @ 136k. Power was great ran like a champ.

At about 170k, I lost my 1st gear from the 'D' position. I still have '1' and can shift into
'D' when I get to about 8-10 MPH, drove for 20k without any other problems with tranny or engine.

About 190k, 4 months ago, is started noticing it didn't drive with authority like it used to. As I was 'feeling' it out, noticed that when I accelerate in 'D', with tranny in 3rd gear at about 50% throttle, I get 2 noticable surges of power at 2300 RPM and again at 2600 RPM. It shows on the tach and seat of the pants. The surges, quick about a second, feel like the power I 'should' have in the truck.

My gut is that something is retarding the timing, but can't get a good diagnosis.

Had it at an Indy last week on testbook. It was only showing P0333 Knock Sensor 2 Circuit High Input (Bank 2), P0430 & P0420, so they replaced the knock sensor. Of course all the adaptives were reset. I drove progressively better for about 200 miles, thn over the next 200 miles seems to have gone back to were I was previously.

Also noticed that my engine mounts are shot.

I just this morning threw more codes. Read in this order:

P0332 Knock Sensor 2 Circuit Low Input (Bank 2)
P0430 Catalyst System Efficiency Below Threshold (Bank 2)
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0171 System too Lean (Bank 1)
P1171 Oxygen Sensor System Too Lean Fault Banks A & B

Any help will be appreciated.

Bryan

 

[stolenheron]

cant help you with the problem, but give some QT motor mounts a try. i love mine, rides a bit better after i broke both of my stock ones. you definitely get more vibration when you floor it (like when getting on the interstate), but its smooth when idling or cruising.

got any pics of the headers? company who makes them or custom? how is the sound difference? i've got magnaflow exhaust now and i love it.

 

[DiscoArt]

Maybe your aftermarket cam is walking and rubbing on the cam position sensors. Just a thought.

Usually bad cam sensors = no power. Does piper cam use a thrust plate?

 

[kennith]

cant help you with the problem, but give some QT motor mounts a try. i love mine, rides a bit better after i broke both of my stock ones. you definitely get more vibration when you floor it (like when getting on the interstate), but its smooth when idling or cruising.

got any pics of the headers? company who makes them or custom? how is the sound difference? i've got magnaflow exhaust now and i love it.

Those QT mounts are worth their weight in gold. They just feel more solid, which they are. You know you have an engine in there now, as you can feel it.

It may only be in my mind, and who cares if it is, but that first little snap of the throttle feels sharper. "Feels" is good enough when they have everything else covered so well.

It's just more fun to live with, and puts a little more "Land Rover" under the pedal. They are aftermarket, and they are blingy, but somehow, they just feel like they belong there.

That's all a matter of opinion, however. The only fact I have on the matter is that they aren't as prone to failure as the factory mounts.

Cheers,

Kennith

 

[stolenheron]

it definitely "feels" more torque-y with the mounts installed.

there is also a company called OE? making solid mounts like QTs as well.

sorry for the thread hijack

 

[bryno]

Will look at the QT's when I get to that point, thanks.

 

[Chris-St Louis]

Have you checked backpressure and vaccum with a gauge?

 

[bryno]

Back-pressure where?

Have you checked backpressure and vaccum with a gauge?

 

[bryno]

The interesting thing is, at least to me, is that there is a consistent surge or increase in power/RPM at the same RPM range. It is something that doesn't happen in at other RPM's and that I can recreate nearly everytime.

There are no TPS codes, but would the TPS have this affect, w/o a code?

 

[bryno]

Look through my posting history. I have a thread somewhere with pics and soundbites too, if they are still alive. They are hedman headers, for the Rangie, right hand drive i think.

got any pics of the headers? company who makes them or custom? how is the sound difference? i've got magnaflow exhaust now and i love it.

 

[bryno]

Going to bump this one back up. I really could use some advice here. Since there aren't any current codes, I am not sure where to go from here. It is still running like crap.

 

[jhawk]

All of the codes can be explained by th e lack of cats and bad motor mounts. You already know there is something wrong with your tranny. IS it really power loss or are you losing power through a slipping tranny?

Jim

 

[bryno]

Strange update!

23 month ago, my transmission stopped working in 'D' from dead stop, as explained above.

Last Monday, it started working again. I guess it was a clogged valve? Anyway, tranny is alive and working; functionally 100% and no codes.

 

[bryno]

So now, back to my engine problem. I have no codes, currently. I have no tranny problem. But I still have significant power loss with surges of power at 2300-2600 RPM particularly.

Occasionally I can hear the engine ping and instantly reduce power (retard timing).

 

[KyleT]

get the transmission faults read.

IIRC the tcm sends a signal to the ecm to reduce power during shifts to make it shift smoother. i wonder if the trans control modle is crapping out or has an issue in the system causing this.

 

[Oldnintheway]

Have you hooked her up to a testbook or similar? have you sent an email to the guy that built your engine?

 

[bryno]

So I am back on this problem after no resolve on the engine.

Good new is that the transmission is still working fine. I guess the ole 'never change the tranny fluid' scenario was true in my case. It took two years for a valve to get unclogged once clogged.

So back to my current engine woes and codes:
- P0332 Knock bank2
- P0420 cat sys below threshold
- P0153 Sensor circuit slow response bank 2 sens 1

Since my transmission is functioning correctly now, it seems more obvious that I am loosing power through timing. I can occasionally accelerate 3/4ish and hear the ping -n-retard, ping-n-retard, etc.

Have recently cleaned my MAF and O2 plugs, but havn't thrown $ at swapping yet.

Any help please?

 

[Ed Cheung]

Your engine is running without cats?

 

[bryno]

Your engine is running without cats?

no.......

or maybe, yes, for off-road purposes only!

 

[singingcamel]

you may want to advance the timing a tooth or two. I had a rr classic with a diff cam and headers , i cant remember what kind but had alot of issues with the timing ,don't know why but it seemed I had to advance it to improve performance a time or two.
Check the fuel filter and you may want to clean your sensors up.making sure they are not all carboned up.