L27 under LN3 Induction
#41
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Originally Posted by BillBoost37
Wow...great progress. Keep up posted.
Waiting to see if there is much diffrence between the L27 block and LN3 block in terms of power...
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#42
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Originally Posted by opensourceguy
The dipstick differences may not be due to differing sizes of oil pans, but perhaps different oil capacities. Maybe one of the engines was on an SSE, and the SSE has a higher oil capacity than the lower trim levels. But the pans don't differ.
The bellhousing covers that go on the bottom are different between the two. Putting the original LN3 covers back on the L27 engine turned out to be very difficult. I am quite sure the pans are different. And more than just one having a sensor and the other doesn't.
On another topic, I was planning on using the gear reduction starter the L27 had. But, it is longer, although smaller overall, and hit the engine oil cooler lines, so I had to put the "regular" LN3 starter back on. Since I've had several starter failures between the two Bonnevilles, I was looking forward to the updated design. Oh, well. If the '91 starter ever fails again, the GR starter can go on it - no engine oil cooler.
#43
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Got it back together and started it up. It'* got a definate miss, can't seem to trace it down to one particular cylinder. It'* setting code 41, cam sensor, popped that off and the interrupter just happened to be by the sensor hole - no magnet. When the '91 lost the interrupter magnet, it set the code but didn't miss. Somehow I don't think those two are related.
Guess I'll be pulling the front cover. Might do a compression check as well (should have done that when the engine was on the floor, I suppose). I had put a new timing set and interrupter on the '90 when I first checked out the oil pressure problem, guess I'll put those on the L27.
Guess I'll be pulling the front cover. Might do a compression check as well (should have done that when the engine was on the floor, I suppose). I had put a new timing set and interrupter on the '90 when I first checked out the oil pressure problem, guess I'll put those on the L27.
#46
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I don't consider the need to pull the front off of the engine as a "minor bug to work out", but that'* probably just because I'm tired of working on this car and need time to work on other things. Plus, the SSE gets a lot better gas mileage than the van my wife is having to drive around since her car is out of commission.
I may be wrong about the sensor not causing the miss. According to our beloved Admin jr's3800, "When a Code 41 sets, the ECM uses the last known cylinder #1 TDC reference, or the last SFI reference pulse... With no idea what or where the fuel pulse is the car will not run worth a ***^... " Since the computer had no previous reference (at least nothing usable), it'* lost.
That makes me feel better - at least if that'* the case, I can stop worrying about a dead cylinder in the L27.
The busted interrupter is probably another reason the engine was available to me. The seller said he got the car from the original owner, and it needed a new cat & muffler, new front fenders, but that it ran well. He seems to have convienently left off the part about the check engine light coming on.
I may be wrong about the sensor not causing the miss. According to our beloved Admin jr's3800, "When a Code 41 sets, the ECM uses the last known cylinder #1 TDC reference, or the last SFI reference pulse... With no idea what or where the fuel pulse is the car will not run worth a ***^... " Since the computer had no previous reference (at least nothing usable), it'* lost.
That makes me feel better - at least if that'* the case, I can stop worrying about a dead cylinder in the L27.
The busted interrupter is probably another reason the engine was available to me. The seller said he got the car from the original owner, and it needed a new cat & muffler, new front fenders, but that it ran well. He seems to have convienently left off the part about the check engine light coming on.
#47
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Originally Posted by five7kid
I don't consider the need to pull the front off of the engine as a "minor bug to work out", but that'* probably just because I'm tired of working on this car and need time to work on other things. Plus, the SSE gets a lot better gas mileage than the van my wife is having to drive around since her car is out of commission.
I may be wrong about the sensor not causing the miss. According to our beloved Admin jr's3800, "When a Code 41 sets, the ECM uses the last known cylinder #1 TDC reference, or the last SFI reference pulse... With no idea what or where the fuel pulse is the car will not run worth a ***^... " Since the computer had no previous reference (at least nothing usable), it'* lost.
That makes me feel better - at least if that'* the case, I can stop worrying about a dead cylinder in the L27.
The busted interrupter is probably another reason the engine was available to me. The seller said he got the car from the original owner, and it needed a new cat & muffler, new front fenders, but that it ran well. He seems to have convienently left off the part about the check engine light coming on.
I may be wrong about the sensor not causing the miss. According to our beloved Admin jr's3800, "When a Code 41 sets, the ECM uses the last known cylinder #1 TDC reference, or the last SFI reference pulse... With no idea what or where the fuel pulse is the car will not run worth a ***^... " Since the computer had no previous reference (at least nothing usable), it'* lost.
That makes me feel better - at least if that'* the case, I can stop worrying about a dead cylinder in the L27.
The busted interrupter is probably another reason the engine was available to me. The seller said he got the car from the original owner, and it needed a new cat & muffler, new front fenders, but that it ran well. He seems to have convienently left off the part about the check engine light coming on.
Its hard for me to say what the problem is on that motor, But the ECM uses the interupter/Cam sensor for a cylinder #1 TDC reference... Without it its lost in a way... The crank sensor does so much, but the ECM will have no idea where #1 TDC is, this means that the ECM can not operate in true Sequential Fuel Injection mode, the ECM will them revert back to a good know SFI pulse or what the ECM has Learned... at that point you have a 1 in 6 chance that the car will be a totall dog... Turn it off and start it again and it may run good... The next time it may be a bit crappy....
But being that the battery has been dissconnected, and there is no #1 TDC reference, I believe that the ECM is confused...
Pulling the timming cover isn't a huge headache, but after all of the work you have done, I myself for sure would have lost my cool, dropped the hood and walked away...
I know how you feel, and I hope that you'll have the time to tackle the problem...
And the compression test you were talking about, if you do it, at least you'll have a good idea of what shape the rings and valves are in... May be worth the time to make sure there aren't any internal problems...
I believe that a timming set is $40, the interupter is $14 and the timming cover gasket set is $15... Autozone should have all of them...
Best of luck to you on this project... and keep us informed..
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#48
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Code 41 is a "minor bug" - you do not need to disassemble the front of the engine. See http://www.performanceresearch.us/pa...ars/cammag.htm
#49
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Sorry..I meant you got it..swapped the parts, over came big hurdles and that to pull the cover and do this is pretty small compared with everything you've already done.
We know you can do it... sometimes the cars want us to drink..
We know you can do it... sometimes the cars want us to drink..
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I'm not sure I'd be comfortable trying to JB the interrupter in. The LN3 has all new timing parts, including the interrupter, I think I'd rather get that stuff in the engine than take a shortcut at this point.
Not that I'm all that impressed with the OEM design for the interrupter. JB and the plastic tangs may be the hot ticket.
I'll agree, Bill, compared to what I've done, this is minor. It'* still several hours out of my life that could have been used in other ways. On the other hand, this is something I could have checked while the engine was out, and it would have been much easier to replace then. Good ol' 20/20 hindsight.
At least the L27 has oil pressure.
Not that I'm all that impressed with the OEM design for the interrupter. JB and the plastic tangs may be the hot ticket.
I'll agree, Bill, compared to what I've done, this is minor. It'* still several hours out of my life that could have been used in other ways. On the other hand, this is something I could have checked while the engine was out, and it would have been much easier to replace then. Good ol' 20/20 hindsight.
At least the L27 has oil pressure.