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AFM Mod issues

2K views 5 replies 5 participants last post by  GreyFalcon 
#1 ·
A quick question, I've done the AFM Mod as specified and other than eating up lots more gas it doesn't seem to be giving me more preformance. I understand that it'll run richer with the mod but my digital dash fule gage dropped a full two bars after maybe 30 min of driving, admittedly it was at high speeds ;-) but still, gas is $1.60+ so is it worth it?I've got a K&N cone filter on it with the stock piping. I moved the spring forward 4 notches and that seemed to help but I also was getting a strong gas smell and the exhaust smell seemed stronger also. Since then I've moved it to two notches past stock and it doesn't seem to help either problem. I've got the stock cat. and 2.25 exhaust with a magnaflow high flow exhaust muffler. Anyone else with this mod? How has it worked for you and whats the supposed difference in performance?
Thanks Brian
 
#2 ·
For the mods you have where it is at stock is probably fine. You might see at most 5-7 rwhp, probably more like 2-3, for the AFM mod. You have to be kinda careful with the mod because you can screw up the 02 sensor and cat by adjusting it too rich. I think I screwed up my orginal 02 sensor playing with the AFM on the dyno.
 
#4 ·
One of the things we learned from this MAF conversion, is that the closer you are to stock, the better than stock AFM and fuel delivery is. I wouldn;t think you would see much gain from tinkering with the AFM unless you had a full intake and exhaust (or a 6M with the stock 182 injetors), simply because then, your able to flow the extra air that is needed to take advantage of the extra fuel that you get by Modding the AFM. If any part of that equation is missing, IMO, the AFM mod isn;t worth it.
 
#5 ·
Thanks for the info

Thankss guys, i just happened to have a spare AFM lying around that I didn't think was working right anyway. I put the stock ARM back in today and it did seem to be a bit sluggish compared to the modified AFM so maybe it was working. I'm going to leave the stock one in for now to save gas :D . BTW: I saw a few members from VA responded to me. Would you happen to know of any junkyards in the DC,VA,MD area that I could go look for Supra parts. I need some small interior parts and some plastic lenses for the rear too. Plus I'd just like to see if theres anything else I might want. If ou do let me know, Thanks. I also have a "wanted" so take a look and see if you can donate any parts! Thanks Brian
Fairfax,VA
 
#6 ·
I had tried the AFM mod, and went back to the stock AFM. I've got the intake and exhaust mods. I had some flat spots in the power band, especially off the line, and in the normal driving range just before downshift (automatic) lugging just under 2,000 RPM. I had burnt the ground electrode off of my #1 platinum plug at 30,000 mi., and each plug was progressively better until #6, that was almost perfect. #3 looked like classic detonation, but none of the others were like that. I had replaced my EGR valve, but I wasn't getting any EGR when I opened the valve to test it at idle. I took the throttle body off today, and cleaned the EGR passage that turns down into the intake plenum. That was totally blocked, and I cleaned the passage from the access plug near the firewall. Well, power is back, no flat spots, and there is a lot more power off the line. To make a long story short, the 5MGTE will not run right at all without a properly operating EGR system. That cooling effect of the EGR makes all the difference in the world on how it runs. I also found what I believe might have been a vacuum leak, a split hose at a connection, but that might have happened when I was moving the throttle body out of my way when I was cleaning the EGR passages. This solved a lot of things that I didn't like about how my car ran. I would bet that there are a lot of 5M's out there that need attention in this area. This made a huge difference. I may try my other AFM out again, now that things are running right, but it may just be a waste of gas. If I had the money right now, I would say with some fuel system modifications, this car is ready for one of Arron's mild turbo kits. At 177,000 mi., without any lower end work, I don’t think anything over 8 lb. boost would be wise. :D Kreber and I are up in Western Loudoun, not far from Fairfax.
 
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