Still breaking up and backfiring
07-31-2010, 07:45 PM
#21
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Also, not sure if it has been mentioned but a slightly damaged reluctor could become a problem at higher RPM's. Maybe when the oil pushes back to the back of the pan, it's having problems picking up the damaged tooth? I'm just reaching here as it seems that you have addressed all the obvious stuff.
I'm going to run it with no boost and see what happens also going to try it with a smaller pulley depending on the results with no boost.
Thanks for all the ideas hopefully the problem will finally turn up we'll have it well documented for others.
08-01-2010, 06:22 AM
#22
It hadn't Fuel slosh was one of the first thing I assumed since I had a crappy DIY fuel bucket with two pumps jammed in there. Anyway I put lonnies kit in no change and I'm not using the HOBBS switch as not to complicate this problem further.
Interesting would you say the car did the same thing where it lost all power at high rpms and then proceeded to sputter die and backfire. If so I'll replace the injectors ASAP of course I'll have to probably retune it.
Yea no kidding about the crank I can't imagine the stress this is putting on my engine trying to diagnose this.
Interesting would you say the car did the same thing where it lost all power at high rpms and then proceeded to sputter die and backfire. If so I'll replace the injectors ASAP of course I'll have to probably retune it.
Yea no kidding about the crank I can't imagine the stress this is putting on my engine trying to diagnose this.
As for the + draw..What does the batt voltage show on the logs?? [I don't have HPT]
Batt in the trunk? How are the cables run? Using the body as a ground?
Can you set up a pid to log fuel psi?
Last edited by Old Geezer; 08-01-2010 at 06:34 AM.
08-01-2010, 06:45 AM
#23
Airc.. Also, not sure if it has been mentioned but a slightly damaged reluctor could become a problem at higher RPM's. Maybe when the oil pushes back to the back of the pan, it's having problems picking up the damaged tooth? I'm just reaching here as it seems that you have addressed all the obvious stuff.
Someone had devised a way to test wheel run out thru the sensor hole, comes to mind.
A bore scope could allow a look, w/o disassembling the engine?
Off the cuff: Does the t-400 have the converter circuit modified to control psi?
Excessive psi will push the verter off the support, and can trash the thrust brg.[Many v-sicks Buicks suffered this fate!]
Could it be, the thrust is worn enuf to allow the crank sensor wheel to move far enuf to cause the signal loss?
08-01-2010, 04:42 PM
#24
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We logged fuel psi by using a oil pressure gauge and a hp tuners PID it was doing like it should.
Off the cuff: Does the t-400 have the converter circuit modified to control psi?
Excessive psi will push the verter off the support, and can trash the thrust brg.[Many v-sicks Buicks suffered this fate!]
Could it be, the thrust is worn enuf to allow the crank sensor wheel to move far enuf to cause the signal loss?
You lost me a little bit there I'll try my best to answer I don't know much about different types of converters and transmissions. I installed my converted and took it on and off a few times it doesn't have anything hooked up to it or the transmission it's all mechanical (hope that answers what your asking).
Excessive psi will push the verter off the support, and can trash the thrust brg.[Many v-sicks Buicks suffered this fate!]
Could it be, the thrust is worn enuf to allow the crank sensor wheel to move far enuf to cause the signal loss?
You lost me a little bit there I'll try my best to answer I don't know much about different types of converters and transmissions. I installed my converted and took it on and off a few times it doesn't have anything hooked up to it or the transmission it's all mechanical (hope that answers what your asking).
Last edited by laughatrice; 08-01-2010 at 09:24 PM.
08-01-2010, 05:55 PM
#26
Here's a.. [QUOTE=laughatrice;13677683]Usually about 12.5 or 12.6 via hptuners pretty steady the whole time. Batt is still up front. Theres a couple of grounds off the battery an extra one to the chasis and then the one to the block also added another one from the block to the chassis again.
We logged fuel psi by using a oil pressure gauge and a hp tuners PID it was doing like it should.
good thread at TB.com. This has been a problem w/ the Buicks. Here's a thread involving a LS engine...Don W. [Don ****] is the guy I learned the fix from, as my v-sicks/t-400 combo ate the thrust brg.
Check the crank end play. If it's way too much, the crank sensor / wheel may be out of line enuf to cause this problem..
http://www.turbobuick.com/forums/tra...s-big-ls2.html
Camarod may have a good point. I think that 12.5v is low. When under boost, the load on the plugs/coils/wiring goes up. [hi cyl psi.] I'd want to see at least 13.2+.
We logged fuel psi by using a oil pressure gauge and a hp tuners PID it was doing like it should.
Off the cuff: Does the t-400 have the converter circuit modified to control psi?
Excessive psi will push the verter off the support, and can trash the thrust brg.[Many v-sicks Buicks suffered this fate!]
Could it be, the thrust is worn enuf to allow the crank sensor wheel to move far enuf to cause the signal loss?
You lost me a little bit there I'll try my best to answer I don't know much about different types of converters and transmissions. I installed my converted and took it on and off a few times it doesn't have anything hooked up to it or the transmission it's all mechanical (hope that answers what your asking).
If I'm following you correctly you mean excessive pressure inside the converter causing it to move away from the transmission towards the thrust brg causing damage. I'm not sure I assume if I pulled the transmission this would be fairly obvious where the converter meets the engine. I have a spacer in between my converter and the crank converter needed it for an LS1. The clearance was right though when I checked. This is the first thing that actually pertains to when all this started I had just changed out the converter first time I ran it after I swapped it so it caught my attention.
Excessive psi will push the verter off the support, and can trash the thrust brg.[Many v-sicks Buicks suffered this fate!]
Could it be, the thrust is worn enuf to allow the crank sensor wheel to move far enuf to cause the signal loss?
You lost me a little bit there I'll try my best to answer I don't know much about different types of converters and transmissions. I installed my converted and took it on and off a few times it doesn't have anything hooked up to it or the transmission it's all mechanical (hope that answers what your asking).
If I'm following you correctly you mean excessive pressure inside the converter causing it to move away from the transmission towards the thrust brg causing damage. I'm not sure I assume if I pulled the transmission this would be fairly obvious where the converter meets the engine. I have a spacer in between my converter and the crank converter needed it for an LS1. The clearance was right though when I checked. This is the first thing that actually pertains to when all this started I had just changed out the converter first time I ran it after I swapped it so it caught my attention.
Check the crank end play. If it's way too much, the crank sensor / wheel may be out of line enuf to cause this problem..
http://www.turbobuick.com/forums/tra...s-big-ls2.html
Camarod may have a good point. I think that 12.5v is low. When under boost, the load on the plugs/coils/wiring goes up. [hi cyl psi.] I'd want to see at least 13.2+.
08-01-2010, 09:30 PM
#27
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Yea I thought 12.5 was a little low and that's what it reads off my voltmeter as well once the car is warm when it's cold it's around 14. I changed the alternator with a stock replacement it didn't change this at all maybe I need a high output alternator. I have quite a few accesories drawing off the + post and my fuel pump hot wires connect right to the alternator I may remove my accessories and see if I get a higher voltage reading.
I took my voltmeter through the fusebox and got pretty consistent readings some of the fuses were a few tenth's lower than other but I don't think too significant.
I took my voltmeter through the fusebox and got pretty consistent readings some of the fuses were a few tenth's lower than other but I don't think too significant.
08-01-2010, 10:16 PM
#28
Mine is at 13v when it's at full op temp. You can go down to 11.5 without any issues. I wouldn't go down that road at this point.
Check your pigtails and make sure that they are making good contact on your sensors. I just discovered this problem with my TPS today. It has driven me batshit crazy for the last couple months trying to figure out what was going on. Totally intermittent.
Check your pigtails and make sure that they are making good contact on your sensors. I just discovered this problem with my TPS today. It has driven me batshit crazy for the last couple months trying to figure out what was going on. Totally intermittent.
08-02-2010, 08:35 PM
#29
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I spent quite a bit of time driving it today and working on it. I changed the pulley to reduce boost checked a bunch of wires couldn't find anything.
Couple observations while driving around it only seems to do it when the engine becomes unloaded during wheel spin. It's like the PCM can't keep up with rapid changes of engine load, RPM and boost. If the car is rolling about 40mph or so and I go WOT it seems to be fine and just pull on along it's only at low MPH usually. Any thoughts?
Couple observations while driving around it only seems to do it when the engine becomes unloaded during wheel spin. It's like the PCM can't keep up with rapid changes of engine load, RPM and boost. If the car is rolling about 40mph or so and I go WOT it seems to be fine and just pull on along it's only at low MPH usually. Any thoughts?
08-04-2010, 09:52 PM
#32
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Here's what I've found so far. The fuse under the hood INJ1 has a constant current of 2.2V even if the car is off I can also pick this same 2.2V up at the coil packs and where the injector wires out of the PCM. Also on the Ignition relay at the 87 pin shows the same current.
Any ideas to where this is orginating from I'm still doing the trial and error method but I'm hoping this is my problem it doesn't sound normal to me.
Any ideas to where this is orginating from I'm still doing the trial and error method but I'm hoping this is my problem it doesn't sound normal to me.
08-05-2010, 08:02 PM
#33
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So i tracked down the source of the feedback voltage. It has something to do with my SLP fan control harness when that thing is hooked into the harness the voltage is present when I remove it the voltage is back to zero. I removed it no change in the cars performance.
Just checking things since I've already replaced the crank sensor should I replace the cam sensor too. I know it's generally associated with starting issues but fine once running but if it was intermittent could it cause issues up high?
If this isn't it I'm going down the crank reluctor wheel and crankshaft end play route but that's a big job.
Just checking things since I've already replaced the crank sensor should I replace the cam sensor too. I know it's generally associated with starting issues but fine once running but if it was intermittent could it cause issues up high?
If this isn't it I'm going down the crank reluctor wheel and crankshaft end play route but that's a big job.
08-05-2010, 09:48 PM
#35
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I started thinking the reluctor wheel is screwed up so I started checking out my transmission to block connection and the damn dowel pins for the tranny have fallen out I'm not sure if this is causing some flex in there when the engine torques over but it's not good so I'm going to replace those.
08-06-2010, 06:09 AM
#36
"If this isn't it I'm going down the crank reluctor wheel and crankshaft end play route but that's a big job."
It's not a big job. Just bar the balancer back and forth. If it moves more than a "RCH", the thrust is gone.
How in hell did the dowel pins get gone??? Have you knocked them out, before, and they were loose?
No pins, and the trans will move around! The bolts are not a register for the trans case.
It's not a big job. Just bar the balancer back and forth. If it moves more than a "RCH", the thrust is gone.
How in hell did the dowel pins get gone??? Have you knocked them out, before, and they were loose?
No pins, and the trans will move around! The bolts are not a register for the trans case.
08-06-2010, 08:31 AM
#37
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"If this isn't it I'm going down the crank reluctor wheel and crankshaft end play route but that's a big job."
It's not a big job. Just bar the balancer back and forth. If it moves more than a "RCH", the thrust is gone.
How in hell did the dowel pins get gone??? Have you knocked them out, before, and they were loose?
No pins, and the trans will move around! The bolts are not a register for the trans case.
It's not a big job. Just bar the balancer back and forth. If it moves more than a "RCH", the thrust is gone.
How in hell did the dowel pins get gone??? Have you knocked them out, before, and they were loose?
No pins, and the trans will move around! The bolts are not a register for the trans case.
Fairly 