knock knock goes the jeep....

[CSH-HQ]

How is the return line routed?.  On some applications, it's wound around all 
kinds of hot parts, ie tranny, exhaust.
  One one oem app. it ran over the torque converter and along the top of the 
tranny case, and then ran with 4" of the exhaust for about a foot.
  Gee guess what happened on long trips after having the light end aromatics 
boil off (those are the ones that are the octane improvers).
  How is the fuel tank vented?.
How old is fuel pump/relay?.
Grumpy



>Here's a problem that I'm working on....
>>engine: '88 TPI 5.0L with Vortech SC (FMU and MSD boost retard) running
>>'7730 with '92 axxc bin (nearly identical to anth etc..). This is in my
>>Jeep with an NV4500 trans (5-speed manual 0.72 or-so over-drive, 4.10
>>gears, 33" tires).
>>problem:
>>I'm was cruising on the highway in 5th and started up a moderate grade
>>while following someone. As the person moves over, I
>>down shift into 4th (about 6845 sec on the tps plot of
>><ftp://jsgpc.mrcday.com/pub/knock/tps.jpg>), delay a few seconds till
>>the road was clear and gave it some gas... heard it knock... I lifted then
>>tried again around 6850 seconds... still no go. At about 6855 seconds,
>>I shifted back into 5th. From about 6855 seconds and on, it was in 5th and
>>now knocking. It didn't fully recover until about 6960 seconds.
>>
>>The spark advance is plotted in
>><ftp://jsgpc.mrcday.com/pub/knock/sprkAdv.jpg>, and the rpm in
>><ftp://jsgpc.mrcday.com/pub/knock/rpm.jpg>. As I went back into 5th at
>>6855 seconds, the knock sensor has pulled out almost 20 deg of timing
>>(the timing goes into retard and is also shown as such in MW1)
>>BUT... it's still knocking. no real boost at this rpm and something
>>that it would not otherwise do.
>>
>>I believe this has only happened three or four times now. Each on long
>>trips and shifting down to fourth to pass.  Other than that, the car
>>has been running fine. Accelerating from a stop or slower speed has
>>not had any such problem.
>>
gwynne