Rattle at high rmp...is it detonation? is my motor pooched?

You're on the right track then.
Pump and clean the tank is next. Followed closely by injectors and chip. If you know your goals will include a turbo and or more bolt ons in the future, go ahead and get injectors and chip now. For the money, I wouldn't waste it on cleaning the injectors. Especially if you don't know the age of them. If they are original 28#ers, I would keep them, but not use them. Most vendors who still offer cleaning services get $60 - $70 per injector, and by that time, you're better off getting a new set.

I know at this point, it seems like everyone is telling you to keep throwing money at it, but if those injectors are questionable, I would swap them and add a combo matching TurboTweak chip at the same time. The pump, and injectors with a combo matching TT chip are critical for reliability. It is good to see you're making progress. Stick with it and we're all here to help.

-Patrick-
 
Yes, it seems like all we are saying is spend on this or spend on that but like Patrick said this is critical. Fastest way to a blown engine is leaning out because of fueling issues. You'll have to decide if you want performance or just a great running low mod car. That would send you down a different mod path.
 
right now i just want a good running car with low mods like a couple more pounds of boost and a chip/injector combo. was hoping to mod slowly any enjoy the car. since the season is ending and the car has spent most of its time up in the air since i owned it i am going to acquire the parts over the winter and get the car ready for next spring. at least i will get a few more cruises out of it this year without putting my foot down.

Pronto, in your pm you mentioned a new hotwire kit. can these go bad sometimes. bad connections or relay/?
 
If you go the route with a fuel pump, you might as well go with a new sending unit since they flow better and have upgraded wiring. At that point not knowing the quality of the hot wire on there, it makes sense to complete the upgrade front to back. If the tank has significant amount rust then can that too. There will be no guessing then if the fuel system is in boost ready shape. Later if you want to mod then you're all set.
 
If you want to just cruise it around until the season ends and then make some mods over the winter, put the highest octane gas you can get at the pump in it, and maybe splash in a gallon or two of race gas or xylene. You want zero knock. Otherwise your winter upgrades might include new head gaskets.
 
Pronto said:
If you go the route with a fuel pump, you might as well go with a new sending unit since they flow better and have upgraded wiring. At that point not knowing the quality of the hot wire on there, it makes sense to complete the upgrade front to back. If the tank has significant amount rust then can that too. There will be no guessing then if the fuel system is in boost ready shape. Later if you want to mod then you're all set.
Click to expand...

yes, i will get everything sorted out. just gotta give my bank account a rest. most parts have to some from the USA. so we have to add 25% to convert to CAD plus extra shipping cost and duty, brokerage fees. a lot shipments almost end up twice the price. Will try and source some things from local members.

Hopefully i can keep the tank. it looks brand new on the outside. I am sure i will be posting again when i get working at it again.
 
I hear you. Inspect first, you may not need a tank.
 
I was getting knock before WOT. If I were to make a pull making sure I am at WOT and get no knock. What would that tell me ?
 
jshot said:
I was getting knock before WOT. If I were to make a pull making sure I am at WOT and get no knock. What would that tell me ?
Click to expand...

If the fuel system was up to par and the tune is on the team, with all of the other bugs worked out, then that means it could be false knock. But I highly doubt that is the case in this instance.

False knock is typically be caused by the downpipe hitting the firewall to floor pan seam when the engine rocks over under WOT. There are a few ways of addressing this.

- RJC's HD Motor brace kit (Highly recommended, I run it myself)
- HR Parts N Stuff motor mounts (Excellent mounts, but they do raise the engine slightly vs OEM rubber mounts)
- Old school torque strap (Not recommended, as it puts un-necessary stress on the accessory bracket and can crack it over time)

It can also be caused by:

- Loud valve train noises
- Wiped cam lobe or failing lifter/lifters clacking away
- Broken rocker shaft
- Loose flexplate/torque converter bolts
- Exhaust rubbing on a driveshaft
- Axle tube hitting a tail pipe under hard launches
- And in some extreme cases, a severe exhaust leak.

The factory knock sensor is just a glorified microphone, that listens for a certain frequency. It's one of the best tools we have for keeping these engines together.
Keep us posted.
 
RUQWKNF said:
If the fuel system was up to par and the tune is on the team, with all of the other bugs worked out, then that means it could be false knock. But I highly doubt that is the case in this instance.

False knock is typically be caused by the downpipe hitting the firewall to floor pan seam when the engine rocks over under WOT. There are a few ways of addressing this.

- RJC's HD Motor brace kit (Highly recommended, I run it myself)
- HR Parts N Stuff motor mounts (Excellent mounts, but they do raise the engine slightly vs OEM rubber mounts)
- Old school torque strap (Not recommended, as it puts un-necessary stress on the accessory bracket and can crack it over time)

It can also be caused by:

- Loud valve train noises
- Wiped cam lobe or failing lifter/lifters clacking away
- Broken rocker shaft
- Loose flexplate/torque converter bolts
- Exhaust rubbing on a driveshaft
- Axle tube hitting a tail pipe under hard launches
- And in some extreme cases, a severe exhaust leak.

The factory knock sensor is just a glorified microphone, that listens for a certain frequency. It's one of the best tools we have for keeping these engines together.
Keep us posted.
Click to expand...

I am also confident the knock is real. Lots of good info here on false knock.

Could the chip be putting in too much timing before the fuel enrichment happens? Just curious. I know this is not my issue. I can never learn enough.
 
Yes in deed. That's one of the features that makes the TT chip superior. You can play with the timing and fueling. Each engine will be a little different in what it likes. With the TT chip you can work with the tune.
 
i promised i would be back and here i am. here are the off season upgrades i have completed. and Yes. no knock. thanks for your help guys. getting the fuel in tune is key.

comp 980's
MAF pipe
340 pump
new hotwire
RJC plate
60# injectors
TT chip.
adjustable waste gate. @17 currently
and a few more gauges.
 
jshot said:
i promised i would be back and here i am. here are the off season upgrades i have completed. and Yes. no knock. thanks for your help guys. getting the fuel in tune is key.

comp 980's
MAF pipe
340 pump
new hotwire
RJC plate
60# injectors
TT chip.
adjustable waste gate. @17 currently
and a few more gauges.
Click to expand...
very good!
 
one question for the gurus what is the recommendation on when to change o2 sensor, do they get dirty/clogged up or what is there a specific live span on them
 
grass doctor said:
one question for the gurus what is the recommendation on when to change o2 sensor, do they get dirty/clogged up or what is there a specific live span on them
Click to expand...
depends on fuel being used,once the counts start to get lazy its time for a change inmo,unless you want to stay ahead of it
 
From Vortex Buicks:
cc = Cross Counts
Cross Counts are the number of times that the factory O2 sensor has crossed from lean to rich across the stochiometric point (0.441v) during the sample rate of the scan tool. The more active the sensor is, the better job the ECM will do in keeping the A/F at the desired stochiometric ratio for idle and part throttle driving. At wide open throttle, it is not used. Many scan tools may show this number as a cumulative addition so that the first frame may be 10 and the second may be 30 which means the second frame was actually 20. When the total reaches 255, it resets to zero and starts over.
Given that a tool like the ScanMaster samples at approximately 1.4 second intervals and more sophisticated tools like PowerLogger may provide 20+ fps, one must take this into consideration when looking at the results.
Something like 10-40 cross counts per 1.5 seconds is probably normal. An O2 sensor that is sluggish and consistently is on the low end (count-wise) should be replaced. O2 sensors are cheap and it does not cost much to replace one periodically anyway. If you don't, gas mileage and drivability will soon go down hill.
As stated prior, leaded racing fuel will often drastically shorten the life of the O2 sensor. Symptoms are reduced output, sluggish cross counts, and/or a check engine light. Many believe the Denso sensors resist degradation much longer than do the factory AC sensors. When leaded gas has been used, even the Densos will show a sluggish cross count, but, will sometimes clean back up with use. Watch the counts, if they don't recover to a normal level, put another one in if you want optimum mileage and part throttle performance.
If you have a chip that provides an Open Loop idle, it will probably show zero cross counts at idle and this is normal. Check the cross counts at cruise. Also, do not expect cross counts at wide open throttle.
 
You must log in or register to reply here.

Similar threads

R
First time turbo 3.8 build
Replies
7
Views
632
THensley
T
B
Rebuild time
2
Replies
33
Views
981
TIMINATOR
TIMINATOR
J
High RPM
Replies
6
Views
897
mblum
M
D
Found This In Oil Pan What Is It?????
Replies
2
Views
548
daredevil95
D
C
Need to replace timing chain... What is the best option?
2
Replies
22
Views
1K
1KWIKSIX
1KWIKSIX
Top