Adding fuel but no change??
 

Ok, I have been trying to get the bugs worked out for 2 months now. I believe all is due to one issue that I have not resolved yet. I noticed the other day that when I added fuel in either the correction map or base map my afr's had no change. I added 50% (just to test and saw no change in AFR"S. So I am thinking the wideband is bad but FJO says it will not read wrong numbers if it went bad just slower or get stuck.... I was thinking fuel presure could be droping but have no way right now to confirm.

Any other ideas what could cause me to have no change in AFR"S while added more fuel?


Set up on fuel is stock relay turning on big relay that is wired direct to battery (very heavy guage wire). Dual supra pumps that run -6 to each rail, return is -6.

Were you adding fuel in the idle area to test your AFR's? If so, there will be no change unless you have gone to manual idle, since there are hidden maps for the idle area.

Also is this on the commander or through a datalogit and laptop?

Not Idle as the PFC has its own hidden map for this... and of course this was done with a datalogit.

Any driving area, has no change.

I just spoke to Chris at rx7.com and he gave me a few suggestions. Going to put it on a dyno and check fuel pressure is not dropping off, also sure my wideband is reading correct by comparing to the shops.

I should have changed less items and i would not have had so many damn thing s to double check. LOL...

There are so many places with the PFC and DL to adjust fuel. You should be able to analyze the problem in a couple of hours. Is it the PFC or fuel system?

You do not need a WB to determine what is happening. Idle and cruise are not affected by a week fuel pump that can't keep up with boost. Do the simple Mazda fuel pump tests using a cheap mechanical fuel pressure gauge.

If the fuel system will idle, cruise, and at lease handle mild acceleration, then there is enough fuel capacity to riched up idle and cruise.

Get a fresh and better mind in your area to help you.

Thanks for chiming in Chuck, you are always very helpful! I fresh mind would be great as I have been trouble shooting every night for 5-6 weeks now. Rewiring, testing and so on. I only wish there was a shop close by that could be of any help but in north AL there is nothing. I may give it another week or so then its going on the trailer to get dropped of somewhere??

this pump assemble came right out of ernie T's car and in mine so I feel they should be fine but will do the above test. the pfc is running the maps that BDC made for me awhile back with no changes. I have reloaded it a few times just to be sure. To be honest it really feels like its running to rich as the break up feels the same as before when I had too much fuel as the turbo came on line but the WB shows other wise. I question the WB as at idle I see high 11's low 12's on cold start but then high 12's to 13's once warm. With the 1000 cc pri before I could never get it to idle out of the 11's warm.

1000 cc primaries should only be used on full race engines as they are terrible to idle and cruise tune. They require negative lag to lean out!

550/1600-1680 injectors with a FJO driver are good for over 450 whp at 40psi base fuel pressure. Why do you need 1000 primaries? Good if you are running E85
but still a little big for that. 550 * 1.30 = 715.

going for much more than 450 and yes this will be mainly a drag-street car. My last go around with same inj. set up was seeing upper 80's on duty cycle at 24-25psi mid 500rwhp. (504 @22.5psi) Now, larger ports, Port match with RE mani and 4 inch exhaust a tad more boost going for upper 500's. But first things first.....

I would put an electronic fuel pressure gage with readout in the cabin, going for that much power you really need to make sure the fuel system pressure is spot on.

I learned this lesson the hard way after installing a brand new in-tank pump, pump was damaged and it cost me a motor.

It's also helpful in diagnosing issues, letting you immediately eliminate the fuel system as a problem.

i guess the obvious auto save or save the map after making changes is being done? Just throwing it out there i know it might be a silliy suggestion and very obvious, but you never know.

I have 1000 pri, and 1680 sec (no resistors), and I'm having the exact same problem. I've just put in a GT40r, and I just can't rich it up. It's idling very nicely at 14.7 afr (I didn't tune it for this btw). However, when I load up the boost on a dyno, it will richen up to 13.4, and no matter how much fuel I add to the base or correction maps, it will not go richer. I have tried adjusting inj % based on RPM and PIM with no affect. I am running 36psi base fuel pressure, I have a gauge and can confirm pressure is building with boost and does not drop off.

This is stopping me in my tracks at the moment. I'm suspecting an issue with the 1000cc primaries, had them flowed and they apparently don't have a linear flow characteristic, but this shouldn't matter once the 1680's come online. I'm looking to get a FJO driver and some different primary's. Right now, I can't take my project any further :(

Let me know if you resolved your issue and how!

Thanks

Are you sure that the fuel presure regulator is properly plumbed into the fuel system and that the injectors are not in the return side of the fuel system.
Either the PFC, fuel system, or pump are bad.
Check the seal in the connector between the fuel pump and hard line. They fail. I cut mine off and replaced it with hose.

Yes, the FPR is on the return side of the injectors. I'll check the fuel pumps hoses again, I also thought about changing the fuel filter just to be sure, but would expect the pressure to drop off with either of these.

The only thing that has changed is the new turbo setup and hot wire of the pump. I'd guess it was working fine before that, but to be fair, I hadn't dyno'd it to check AFRs. It may well have been off before hand.

The fuel line I refered to is in the tank. The top of the FP fits into the metal bell shaped housing which contains a rubber and hard nylon piece. These break and cause a leak.

hmm, the only time I ran into that problem under heavy load was because of fuel pressure dropping off due to low fuel pump voltage.

It's still highly likely to be a fuel pressure issue.

I'd expect it to get leaner as RPM/boost increased. It holds a steady 13.4 afr. The FP gauge is showing a steady pressure too. I'm sure it's something to do with my PFC setup, so will just have to play some more with that.

Thanks for the input guys, much appreciated

Maybe it is your wideband or the WB setup.

Are you sure the secondaries are firing? You mentioned not running resisters maybe the injector circuits burned out.

The wideband is coming off the dyno unit, so sure that is accurate. It's being used to map other cars all the time.

I'm thinking it the PFC drivers too. I have ordered an FJO Injector driver to see if it helps the issue. Will let you know.

If the injector drivers are the issue then the fjo won't help because it still requires a signal to convert to peak and hold.

You should test the drivers first to see if that's the problem. You can buy little socket probes that light up. You plug them into the injector clip and they can be found at automotive stores. I can't remember what they are called.

What you can do is plug them in and if you have a datalogit change the secondary times so they come on immediately, then disable your primary injectors, crank the car and see if the socket things light up......Actually an easier free way to test is something similar. Don't worry about getting the socket light probes, just unplug your primaries and change the on time for the secondaries to 0 % so that they come on immediately. You might even put 0 in the fields for the primaries so that the fuel maps would be closer. then start the car. if it starts and runs on both rotors then your secondaries are working correctly. If not then either your injectors, wiring, or PFC has a problem.

I once used a similar method to limp home when one of my primary injectors went out. I just set the secondaries to be used like primaries by setting them on immediately.

Sorry Guys that I didnt come back with the results earlier.. I was right, the issue was indeed the NTK sensor that failed... It is crazy, even FJO had not scene this issue before but when the car is started it reads correct. After 10-15 mins driving it starts to read incorrect... I confirmed with a new sensor. After full warm when I would make changes in the fuel maps it would no show... I had so many things to adjust on this new set. Car runs like a beast now..

When you add the fuel is it breaking up when you go on the throttle a bit? Mine did... Also check your duty cycle before and after the changes are made....

14.7 afr @ idle?? I dont think I have ever scene that lean...

My thought is that the signal is still there, as the injectors are firing. However, I'm thinking the PFC drivers aren't pushing enough power to the injectors to they are slow to respond or don't open fully resulting in the lean afr. In this case, the FJO should still see the signal, but run full power to the injectors. (If I understand the FJO functionality correctly ;) )

My tuner has these already, so will give it a go and see what results.

Good to know, appreciate all the help!

Are you sure the wideband is functioning correctly? Has it been tested with other cars or anything lately? 14.7:1 does seem a bit lean for the car to be idling nicely. Usually once into the 14's the idle gets a little jumpy. I'm also surprised you are able to get 1000cc injectors to idle that lean.

But assuming the wideband is accurate, you said the secondary injectors are firing. How do you know they are? It is possible for only the secondary injector drivers to burn up, so if you are assuming the injectors are firing on the fact that the car runs, this wouldn't be an accurate way of determining if the injectors are firing.

Also even though the drivers in the PFC are not peak and hold, they have no trouble opening peak and hold injectors all the way. The way peak and hold works is a large current is fired to open the injector and then the current is pulled back to keep it open, hence the name "peak and hold" The PFC drivers just open and close the circuit, and since the resistance is lower with aftermarket injectors it pulls more current then the drivers are rated for and can cause damage. Thats's why many people run resistors, including myself. Resistors actually will make the injector respond slightly slower then running no resistor, but even so this also does not keep the injector from opening all the way.

I am fairly certain if your injector drivers are no longer opening your secondaries, that the FJO will be of no use to you until that is fixed. Hundreds of people run the PFC with aftermarket injectors and have no problems with low resistance injectors not opening, with or without resistors. The FJO still uses the signal that goes to the injectors to convert to peak hold, so if that signal is present your secondaries would also be firing. So if they are firing, the FJO will not fix your problem, and if they aren't firing the FJO will not fix your problem.

yeah, I could not get my 1000cc pri's to lean out anymore than high 11's