Symptoms of bad/weak FPR?

[float_6969]

Alright, well I've finally got everything wired up, SDS, gauges, everything. But what I've been noticing is that my AFR's seem to kind of wander. It's like I log a run and when I go to correct the fuel at a certain RPM, it won't seem to match the numbers above or below it.

Example(these are made up #'s):RPM FUEL AFR1000 75 11.51250 76 10.01500 78 12.5

Now I don't think the fluctuations were this drastic, but you get the point. It's not like it's a linear problem. The RPM values should increase pretty linearly with the RPM. But as you can see, I would have to have a higher number at a lower RPM range to make the AFR #'s right. Something just seems off to me.

Here is the info about the fuel delivery. Walbro 255lph fuel pump555cc NISMO CA specific Fuel injectors300zx TT Fuel FilterSDS ECUStock FPR

I haven't checked the fuel pressure yet. I'm going to try doing that this week. If it does turn out to be the FPR, how much trouble have you had doing it while the fuel rail was on the car?

[WeldingHank]

i haven't done it, but it seems to be next to impossible while its on the car. when i was doing my turbo upgrade that was next on the list for the day. but it was getting late and i looked at it for about 20mins and the only way i could think of doing it was taking the rail off.

[biosehnsucht]

nearly impossible, depending on if you can get the damn screws off

replace them with small hex head bolts while you're in there!

also if you use the nismo FPR remember to get some high pressure fuel hose to make a new peice of hose that can loop back around where it needs to go cause the drainback angles off the wrong way..

[float_6969]

Is the problem somewhat consistant?

Innovate WB are somewhat know for that. You add in Lambda input, you readings maybe off. They said they have fixed the problem, but I still see it.

But, check your fuel pressure too.

Consistant in what aspect? Do you mean that the variations are consistant at a givin RPM?

What I'm going to try and do tonight is do 3 1500-7500RPM pulls and write down the results from each run.

I will also TRY and check the fuel pressure. I don't have a gauge mounted in the car, so all I can really do is check it at idle and different vac levels while the car is sitting.

[boost_boy]

Alright, well I've finally got everything wired up, SDS, gauges, everything. But what I've been noticing is that my AFR's seem to kind of wander. It's like I log a run and when I go to correct the fuel at a certain RPM, it won't seem to match the numbers above or below it.

Example(these are made up #'s):RPM FUEL AFR1000 75 11.51250 76 10.01500 78 12.5

Now I don't think the fluctuations were this drastic, but you get the point. It's not like it's a linear problem. The RPM values should increase pretty linearly with the RPM. But as you can see, I would have to have a higher number at a lower RPM range to make the AFR #'s right. Something just seems off to me.

Here is the info about the fuel delivery. Walbro 255lph fuel pump555cc NISMO CA specific Fuel injectors300zx TT Fuel FilterSDS ECUStock FPR

I haven't checked the fuel pressure yet. I'm going to try doing that this week. If it does turn out to be the FPR, how much trouble have you had doing it while the fuel rail was on the car?

So many things play in that area with your standalone. If you think it's the tuning, then take advantage of the open loop on/off option. The most important area you need to be real concerned with are your ratios from 3k and up. If your fuel pressure regulator was playing-up on you, you wouldn't notice it that much down low. But if you were having lean problems under load, then I'll suspect the fuel pump or pressure regulator. But since your figures are rich, I would suspect map adjustments.

Dee

[float_6969]

I'll get some real numbers here in a bit and post them up. Those were just made up numbers to get my point across.