Lean Engine Decleration!
03-28-04, 11:37 AM
#1
Lean Engine Decleration!
Finally my car is running alittle better, it does not bog/hesitate as much, I had adjusted the little screw by the boost sensor and it seem to have cured the bogging a decent amount. I think it was idling to rich, then when I would give it throttle, that is what caused it to bog, It was at 11.5:1 and I upped it to 13:1 at idle, but now when driving aorund 1500-3000 rpm the afrs are around 13.5-15:1......
Anyways this was happening before, when ever I let off of the throttle, the AFRS skyrocket!!! In the 20:1++++m range and back fires/pops ALOT! It did this before I turned the idle fuel mixture screw. Since the engine is still in breakin, I have not revved it over 3K, but just doing laps on my driveway when I am driving and in first gear at about 2500rpm or so and let off the throttle the AFRS shoot up and the car backfires/pops ALOT. The car idles great, and the TPS/acelerator free play cable was adjusted to spec....
What can be done to fix this problem?
Here is a list of mods on the car:
Fresh Reman, Blitz BOV, Just reinstalled stock air box, 2.5" to 3" exhaust allt he way w/ no cats(still have airpump/ACV installed), Injectors were cleaned and balance by RC about 2 weeks ago, new fuel filter, ummm thats about all I can think of that has been done....
Anyways this was happening before, when ever I let off of the throttle, the AFRS skyrocket!!! In the 20:1++++m range and back fires/pops ALOT! It did this before I turned the idle fuel mixture screw. Since the engine is still in breakin, I have not revved it over 3K, but just doing laps on my driveway when I am driving and in first gear at about 2500rpm or so and let off the throttle the AFRS shoot up and the car backfires/pops ALOT. The car idles great, and the TPS/acelerator free play cable was adjusted to spec....
What can be done to fix this problem?
Here is a list of mods on the car:
Fresh Reman, Blitz BOV, Just reinstalled stock air box, 2.5" to 3" exhaust allt he way w/ no cats(still have airpump/ACV installed), Injectors were cleaned and balance by RC about 2 weeks ago, new fuel filter, ummm thats about all I can think of that has been done....
03-28-04, 12:02 PM
#2
I'm with stupid -----^
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Your afr shoots to 20:1 because the car automatically cuts fuel upon decelleration... this is perfectly normal behavior.. nothing to worry about, it's built into the ecu
03-28-04, 01:03 PM
#3
Always something...
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The popping (afterburn) is very normal when you lose the cats, although your ACV may have some issues. I had major afterburn when I simply upgraded my exhaust and intake systems and kept the cat. And as Chris Ng said, the ECU entirely cuts fuel to the engine on decel so your AFR should be approaching free air as the exhaust pipe starts to clear of residual fumes. 
03-29-04, 01:36 PM
#7
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You're one of those, give them a few tools and you get into trouble.
I think I commented in your wide-band thread that it's normal?
But it looks like you don't listen.
You need to read up on what detonation is.
You can't detonate when the engine isn't in heavy load.
Decel is NOT heavy load.
Cruising highway speeds is NOT heavy load.
If you got a boost gauge, ANYTHING under 0 (i.e. vacuum) is NOT heavy load.
Your wide-band is really only good for one thing - WOT.
Stop trying to interpret the wide-band at anything other than WOT.
If you have no idea how the ECU reacts other than WOT, you have no business questioning if it's wrong or not.
-Ted
I think I commented in your wide-band thread that it's normal?
But it looks like you don't listen.
You need to read up on what detonation is.
You can't detonate when the engine isn't in heavy load.
Decel is NOT heavy load.
Cruising highway speeds is NOT heavy load.
If you got a boost gauge, ANYTHING under 0 (i.e. vacuum) is NOT heavy load.
Your wide-band is really only good for one thing - WOT.
Stop trying to interpret the wide-band at anything other than WOT.
If you have no idea how the ECU reacts other than WOT, you have no business questioning if it's wrong or not.
-Ted
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03-29-04, 02:30 PM
#8
HAILERS
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When just tooling around the driveway, disconnect your 02 sensor. The results seen on the afr meter will probably be a touch different. The ECU is trying its best to maintain a fourteen point seven when connected and your tps is still not fully extended. Remember that when you are playing with your safc and trying to lean/richen your afr. Been there....made that mistake.
One heck of a big driveway you got there.
One heck of a big driveway you got there.
03-29-04, 02:34 PM
#9
You can't detonate when the engine isn't in heavy load.
I will admit, I am not bright with the electroincs in cars. But I have disassembled and assembled quite a few cars in my few years on the this earth, and I have not had ANY trouble with them until I got my TII.
Go figure!
03-29-04, 02:38 PM
#10
Originally posted by HAILERS
When just tooling around the driveway, disconnect your 02 sensor. The results seen on the afr meter will probably be a touch different. The ECU is trying its best to maintain a fourteen point seven when connected and your tps is still not fully extended. Remember that when you are playing with your safc and trying to lean/richen your afr. Been there....made that mistake.
One heck of a big driveway you got there.
When just tooling around the driveway, disconnect your 02 sensor. The results seen on the afr meter will probably be a touch different. The ECU is trying its best to maintain a fourteen point seven when connected and your tps is still not fully extended. Remember that when you are playing with your safc and trying to lean/richen your afr. Been there....made that mistake.
One heck of a big driveway you got there.
Yeah my driveway is about 1/4 of a mile long, did a few laps and now have 2 miles on it
Still need to fix my brake problem before i go on the road.
03-29-04, 03:13 PM
#11
Lives on the Forum
Originally posted by eyecandy
So I guess when my engine detonated last October crusing at 2500rpms, wasn't really detonation???? I heard a LOUD pop and bam! No power, couldn't idle, couldn't drive! Took the car part looked at the rotors, hot damn! I blew two apex seals!
So I guess when my engine detonated last October crusing at 2500rpms, wasn't really detonation???? I heard a LOUD pop and bam! No power, couldn't idle, couldn't drive! Took the car part looked at the rotors, hot damn! I blew two apex seals!
There was something already wrong with the engine to cause it to fail.
There is no way a perfectly running engine, cruising on the freeway with no load at 2,500RPM, would detonate and kill itself.
-Ted
03-29-04, 07:51 PM
#17
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Originally posted by RETed
This is almost impossible to do.
There was something already wrong with the engine to cause it to fail.
There is no way a perfectly running engine, cruising on the freeway with no load at 2,500RPM, would detonate and kill itself.
-Ted
This is almost impossible to do.
There was something already wrong with the engine to cause it to fail.
There is no way a perfectly running engine, cruising on the freeway with no load at 2,500RPM, would detonate and kill itself.
-Ted
Oh, non-turbo 82RX-7
03-29-04, 07:54 PM
#18
I'm a boost creep...
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Ted's point is that it's not detonation that killed the engine, not that the engine can't die at low load. There are other ways an engine can die other than detonation, which is purely a high-load phenomenon.
03-29-04, 08:23 PM
#19
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Originally posted by HAILERS
Oh, trust me, a rotary will do just that. The only one that went on me was my 82. Ran just fine. Got up to go to Jury Duty. Doing maybe 45mph, no stress, no strain. Then I really don't remember the sound, but it was running on one rotor and I barely made it to court. No real sign prior to it going. Except for the last winter before it's demise it was hard to start and on occasion I had to pour a little motor oil in the carb to get it to start.
Oh, non-turbo 82RX-7
Oh, trust me, a rotary will do just that. The only one that went on me was my 82. Ran just fine. Got up to go to Jury Duty. Doing maybe 45mph, no stress, no strain. Then I really don't remember the sound, but it was running on one rotor and I barely made it to court. No real sign prior to it going. Except for the last winter before it's demise it was hard to start and on occasion I had to pour a little motor oil in the carb to get it to start.
Oh, non-turbo 82RX-7
03-29-04, 08:30 PM
#20
Originally posted by ERAUMAZDA
So your saying you have 0 psi all arounf on the rear.
So your saying you have 0 psi all arounf on the rear.
I am sure my engine had detonated a few times under load, and one last detonation at crusing is prolly what killed it.
Hmmm something I just realized, we are talking about detonation, after the initial spark of the air/fuel. Don't for get about predetonation (pre-igintion), before the spark plug ignites the fuel.... Both are harmful, both can happen at anytime, it is JUST MORE likely to happen at higher loads.
03-29-04, 08:48 PM
#22
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here is the answer to your problem. LOL http://www.prepsparkplugs.com/frames.htm
03-29-04, 08:48 PM
#23
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Originally posted by NZConvertible
Ted's point is that it's not detonation that killed the engine, not that the engine can't die at low load. There are other ways an engine can die other than detonation, which is purely a high-load phenomenon.
Ted's point is that it's not detonation that killed the engine, not that the engine can't die at low load. There are other ways an engine can die other than detonation, which is purely a high-load phenomenon.
*****So I guess my engine didn't blow then! 102psi in front rotor and 0psi in rear,
hmmmmm interesting!****
What makes them go is WORN OUT APEX SEALS. They're worn out for several reasons. Neglect being the number one culprit in my case.
Last edited by HAILERS; 03-29-04 at 08:50 PM.
03-29-04, 08:55 PM
#24
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Originally posted by ERAUMAZDA
LOL...how many miles, how do you know it was detonation. Could have been a lot of things.
LOL...how many miles, how do you know it was detonation. Could have been a lot of things.
I corrected my earlier post. No, it was a 82RX. No detonation doing 45mph on a level grade. It was a worn out rotary engine. You know, one that is hard to start on occasion. Real hard to start in the winter. It was a truly abused little engine. Ever pull a NACRA 18 Square over 800 miles in the Texas summer? With the a/c on? It was the little car that could. Well, for about 110,000, then it was a one lunger.
03-29-04, 09:19 PM
#25
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my first motor actually went when i was decelerating coming to a stop light. i pushed the clutch in to change gears and it stalled out. and when it started back up, i had to floor it to keep it running. completely no compression on the rear rotor. and i was actually cranking it and not turning if over by hand to check compression.