Stock GSL-SE Fuel Pump / AFM System
01-24-07, 07:40 PM
#26
Originally Posted by Felgar
Hey Doc, sorry for not posting back. I have very little new news. I did verify the engine fuse in the interior but didn't even verify the fusible links yet (but they look fine visually). I'm waiting on the Air Temp Sensor from a supplier here in Calgary and I'll be picking up the new plugs, cap, rotor, etc from them as well.
I was going to pick up a multi-meter and start verifying the AFM but I've been so busy with other things that I haven't started that yet. And then I came home yesterday and the battery charger I was using reported "charge error" and my battery was stone dead. So I had to spend last night charging back up. I might be able to verify the fusible links tonight, but even if not, I'll report back as soon as I get back to work on it.
Thanks for keeping it in mind though Doc; I really appreciate it.
One thing I've learned is that the RX is no longer a suitable daily driver. Parts are just too hard to get now which makes fixing problems take far too long. But I'll be hard-pressed to find a car that I enjoy driving as much as the SE for less than about 10K, so I don't what to do.
Maybe a BMW 323 or 325 from 94-98...
I was going to pick up a multi-meter and start verifying the AFM but I've been so busy with other things that I haven't started that yet. And then I came home yesterday and the battery charger I was using reported "charge error" and my battery was stone dead. So I had to spend last night charging back up. I might be able to verify the fusible links tonight, but even if not, I'll report back as soon as I get back to work on it.
Thanks for keeping it in mind though Doc; I really appreciate it.
One thing I've learned is that the RX is no longer a suitable daily driver. Parts are just too hard to get now which makes fixing problems take far too long. But I'll be hard-pressed to find a car that I enjoy driving as much as the SE for less than about 10K, so I don't what to do.
Maybe a BMW 323 or 325 from 94-98...As far as a daily driver, once you get the kinks worked out she will be just fine.
As far as parts go just order in a extra set of plugs.cap and rotor. The fuel filter only needs to be replaced every 30k as well as the air filter.
As blazer1313 has stated don't forget to inspect the air intake hose where it joins together to make sure the clamp has not come loose. The only other obvious leak in that system would be the hose that comes out of the air intake at the top and goes into the top of the plenum.
Concerning the AFM test, it's pretty useless. There are only 2 defects that I have found that will occur with the AFM. 1). You have a backfire and the AFM door is bent not allowing it to close. 2). The circuit goes bad internally and allows the fuel pump to come on without cranking the engine.
01-24-07, 10:01 PM
#27
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Originally Posted by rx7doctor
Concerning the AFM test, it's pretty useless. There are only 2 defects that I have found that will occur with the AFM. 1). You have a backfire and the AFM door is bent not allowing it to close. 2). The circuit goes bad internally and allows the fuel pump to come on without cranking the engine.
01-24-07, 10:51 PM
#29
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Well I can say that my AFM door looks undamaged and moves easily (flaps as it cranks over even), and plus I know that the fuel pump is only come on when it's supposed to because of all my investigation into it. So that would rule out both of Doc's failures. Maybe an electrical problem with the AFM though... Who knows.
Maybe an electrical problem with the AFM though... Who knows.
01-24-07, 11:10 PM
#30
Originally Posted by Felgar
Well I can say that my AFM door looks undamaged and moves easily (flaps as it cranks over even), and plus I know that the fuel pump is only come on when it's supposed to because of all my investigation into it. So that would rule out both of Doc's failures. Maybe an electrical problem with the AFM though... Who knows.
Maybe an electrical problem with the AFM though... Who knows.Do you have a compression tester?
01-27-07, 01:55 AM
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I have a regular compression tester but not one that's designed for rotaries. I do know that it puffs pretty strong with the plugs out, and also turns over smooth to indicate that all 3 sides have similar compression. Probably not completely definitive though...
02-12-07, 11:09 AM
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Well, the intake temp sensor is installed. New plugs, cap, rotor are installed. The coolant temp sensor which was mentioned earlier seems to show the proper resistance. The fusible links are tested and good. Still no start.
The diagnostics on the AFM showed only 1 anomaly. According to Haynes, there's one pair of pins that's supposed to be infinite resistance when the flap is closed, and zero resistance when it's "fully open." A fancy way of saying that it's a simple switch, I believe.
Anyways, for me it reads infinite when closed, but changes to zero when it's barely open (like 1/4" movement will cause zero resistance), so maybe that's something. All of the other pins check out on-spec as demonstrated in the Haynes manual.
Tonight I might try to disconnect that pin from the AFM at the ECU so that it reads infinite resistance for the entire start. After that I guess I'll try testing voltages at the ECU... I dunno.
Is there any malfunction that could change the timing dramatically? I suppose I could verify the timing also...
The diagnostics on the AFM showed only 1 anomaly. According to Haynes, there's one pair of pins that's supposed to be infinite resistance when the flap is closed, and zero resistance when it's "fully open." A fancy way of saying that it's a simple switch, I believe.
Anyways, for me it reads infinite when closed, but changes to zero when it's barely open (like 1/4" movement will cause zero resistance), so maybe that's something. All of the other pins check out on-spec as demonstrated in the Haynes manual. Tonight I might try to disconnect that pin from the AFM at the ECU so that it reads infinite resistance for the entire start. After that I guess I'll try testing voltages at the ECU... I dunno.
Is there any malfunction that could change the timing dramatically? I suppose I could verify the timing also...
03-10-07, 08:51 AM
#34
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If I'm thinking of the same circuit, all that is is a switch to tell the fuel pump to start working. Off when closed and on in all other positions. With no sputter no nothing, next I would say ECU...there are checks to see if its ok or not. They're cheap..$40 in the classified section...
03-12-07, 06:32 PM
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Thanks blazer. If that's the case then it's fine because the fuel pump is most certainly working.
I finally caved and took it into a local Mazda dealer who has a guy who apparently knows a lot about these cars. He said the problem is poor compression, but not a blown apex seal as all 3 readings are close. Later I discussed the findings with another forum member and we've diagnosed that it's a side seal that's failed which is leaving very low compression.
Now, it still doesn't explain why it was starting well until one specific morning, because apparently the side seal failure is a fairly gradual process. So the original cause of the non-start is still undiagnosed, regardless of the state of the engine. But given the blown engine I called off any further diagnosis. I don't know what'll happen yet but I think it's the end of an era for me; I've had an FB for about 9 years now and I'll miss having one. I may still keep it but I'm currently leaning towards selling it...
Thanks for all the help and effort guys; I really do appreciate it.
I finally caved and took it into a local Mazda dealer who has a guy who apparently knows a lot about these cars. He said the problem is poor compression, but not a blown apex seal as all 3 readings are close. Later I discussed the findings with another forum member and we've diagnosed that it's a side seal that's failed which is leaving very low compression.
Now, it still doesn't explain why it was starting well until one specific morning, because apparently the side seal failure is a fairly gradual process. So the original cause of the non-start is still undiagnosed, regardless of the state of the engine. But given the blown engine I called off any further diagnosis. I don't know what'll happen yet but I think it's the end of an era for me; I've had an FB for about 9 years now and I'll miss having one. I may still keep it but I'm currently leaning towards selling it...
Thanks for all the help and effort guys; I really do appreciate it.
03-16-07, 05:44 PM
#36
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A rolling GSLSE nonrunning is worth about $400-500...I'd at least give it a rebuild then you could resell for at least $2000 depending on condition..
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