Italian

I drove it this weekend and the problem persisted. I cleaned the fuel filter again as a little more rust make it back in, which signifies that the fuel puck up is the cause of it. Only a little came out, though, so it shouldn't be too big of a deal. I did figure out that the fuel pressure regulator is bust, which is why there was never fuel pressure. My friend's dad suggested clamping the return hose to see if it builds pressure, which it did, and what do you know, fuel pressure. I ordered a Holly pressure regulator to hopefully fix thisand get me home (http://www.jegs.com/i/Holley/510/12-804/10002/-1?parentProductId=#moreDetails). Once I do though, I plan to replace it with a Fuel Lab 525 regulator so that I have a return system. I have a quick question on the regulator though. I plan to use only one of the two outlet ports on the regulator to avoid cluttering up my engine bay, would this cause any flow issues? I've already ordered the fittings and a plug, so now is kind of a bad to to ask, but I can always get another fitting somehow. Thanks

Sorry it's been a while, I've been busy with the end of school. I drained the tank and filtered everything on Sunday. I expected nasty, red gasoline to come out, but that was no the case at all. Here are the buckets in order of when they were filled. First bucket was the first to gas, ect. As you can see, there was a considerable amount of gunk that came out initially, then a little more in the second bucket, and barely any at all in the third. Once I filtered all of that I put it back in and repeated the draining and filtering, and no more sediment came out. I also cleaned the pre-pump filter, but I forgot to get picture. It was full of really thick gunk that I had to clean off the glass with my finger as running water didn't get it off at all. I haven't started or driven the car yet, but I will tomorrow, so hopefully all is good. I'll update here with whatever happens.

I did some searching around last night and I think I'm going to go with a custom tank like in this thread: http://forums.hybridz.org/topic/96955-a-%E2%80%9Cstock%E2%80%9D-fuel-tank-solution/ Benefit of a new Al tank that wont rust, with welded in bungs and such, but without the issue of a fuel cell it seems. Awesome. It looks like I'm going to be doing this at school in a big parking lot, so it shouldn't be an issue. I'll definitely be taking pics of the process and what comes out, it should be pretty neat.

Seattlejester, thats a great idea, cheaper too. Just find a shirt large enough and tie/bungee cord it around the bucket to pour fuel into, then have hose and a valve at the bottom of that bucket to drain the clean fuel back into the tank/gerry can. Yes I'll definitely be thinking of that. Luckily theres no smoking at school (its a boarding school, against the rules) and neither of my friends smoke so their garages would be okay as well. Question though, would it be safe to use an electric fan to ventilate a garage of the fumes? or would I have to worry about arcing in the motor possibly igniting the fumes? Xnke, thanks for the tip! I have a good bit of time to research whether that would still be feasible or if a fuel cell of some sort would be a better option, so I should be able to figure something out.

That is exactly what I was looking for, thanks!! I'm going to do the draining and filtering method one of these weekends as its the most feasible in my situation. I talked with a friend of mine about this last night and the plan is to get a few cheap five gallon buckets, barb fittings, some hose, a simple on/off valve, and a 100 micron mesh filter sock, then set up the whole operation to run in a day. Might do the multiple filters thing, but I'm not sure at the moment. I'll keep thinking about it for sure though. On JNC I got a suggestion of washing the tank and lines out with mineral spirits, which I think I might do to just the hard line running from the pump to the engine bay as I'm sure they're fairly rusty and gunky. I'm gathering parts to re-do all the fuel lines this, so their condition will soon be irrelevant. So the current plan: 1. Wash out tank while I'm at school to get all the current sediment out. 2. Drop the tank once I get home and have it professionally cleaned and treated. Might have a sump welded on, at the least I want AN bungs welded on in place of the barbs for out/return (if this is possible at least). 3. Replace all fuel lines with braided hose and AN fittings.

Its so odd how that works isn't it. I know for sure I will be dropping the tank and having it professionally taken care of in the summer once I'm home from school, but right now my biggest concern is getting the car/tank in a condition where I could drive it the 510 mile trip home once school gets out. I might be able to get it professionally taken care of up here, but its a big might. Obviously there is a lot of sediment in there now, but how long does it take for a decent amount of sediment to build up? I'd assume it varies with tank condition and such, but if I could get all the sediment out of there now, or as much as I can, and make the car drivable for the next month without worrying about having too much sediment build up again I'd be happy. Would that be a possibility?

Heres all the useful info from over the weekend: When I was draining the tank, there was but a trickle of fuel coming out using the fuel pump. This pretty much confirms the suspicion of poor fuel flow. I then went and disconnected the hose that goes from the return line to the tank and let the fuel drain out of there. Next were the filters and some hose. The source of the issue showed itself upon firing up the pump for the first time. A whole hell of a lot of sediment filled up the pre-pump filter immediately. Then the post-pump filter wasn't filling up, but from a little of what I've read I think that is normal. I'm going to figure out a way to drain the tank and try to get all the sediment out, as well as clean out that pre-pump filter. Hopefully I can figure that out before June. The car is running horribly and I believe it's due to the poor flow. Especially considering I could only get a max of 1 PSI of line pressure. If anyone has advice on draining the tank and cleaning it without dropping it, I'd love to hear it.

Update: Starting the car today I noticed the fuel pressure gauge was reading 1, maybe 2 PSI at best when I just had the pump going. This could either be due to the FPR being inaccurate, or the fuel system not being able to flow enough fuel or maintain any higher pressure. Since it needed to be done anyway, and, well, since I already had the parts, I'm going to eliminate the flow side of the equation. It also ended up being the cheaper route Whilst driving the car it bogged a lot less than the last time I drove it, and I noticed it really only did so when I held the car at a speed where the engine was revving over 3000 rpm. If I kept it under that, it seemed to be just fine. Anything over it though, and it bogged pretty quickly. I checked the fuel hard line in the engine bay (bit that goes around the front of the cam cover) and there were no restrictions, so that is ruled out as a possible cause of the bogging. However, I noticed that the inside of the hard liens were rusted and dirty, so I'm going to remove them completely and put 5/16 hose in their place. Won't look the best, but it'll do for the 1 or 2 months before I re-do everything with AN lines. I ordered a Holley Red pump as well as some filters to install this weekend. The current filters being clogged was another possible cause of the bogging, and the fuel pump being already pretty low flow and possibly on its last legs was another. New filters will free up some flow for sure, plus they're both clean so I can see if they're clogged. On top of that, a new pump with nearly 4 times the free flow rate should definitely help. I installed the fittings on the pump just earlier today so that the thread sealant has time to set up before I install the pump. This will also give me time to prepare everything for the install. Container to hold the fuel in the tank, make sure I have all the line and clamps I'll need, figure out wiring, and possibly secure a lift to make the job go a whole lot smoother. I have not checked the float level yet as I realized if I did have to adjust it, I'd need new gaskets for the float bowl lids and since I don't have any spares, it'd have to wait anyway. Hopefully I'll have good news after the weekend!

Ah alright, I'll check that. should that be the case I'll just make a run to the hardware store and pick up some more fuel line and get rid of the hardline. I might just get a new pump then anyways. At the very least, it might reduce noise. Float level check will take place this weekend for sure. So from that list: Electrical: Good Fuel routing: Good Fuel tank: Definite Possibility Clogged filter: Definite possibility, will replace both Fuel pump: Plan to replace anyway, will buy sooner than planned Fuel metering device: Checking this weekend Engine vacuum: Good. I rebuilt the engine last summer and have put ~2000 miles on it. It pulls a very strong vacuum Low fuel: I haven't noticed any difference when there was more fuel in the tank than less, but this sparked another idea. The fuel gauge seems to be off a good bit, and when I took the picture of the pump it looked like it had been bashed in a bit. With those things in mind, theres a possibility that the feed for the pump is no longer at the lowest point of the tank. I'll check it again and make sure that this isn't the case.

Hmm, well alright then. Either way, theres still the possibility that it might be on its last legs. One of the days when it was happening the pump was absurdly loud, so much so that it could be heard over the exhaust (which is quite loud). Also the noise it makes is like a rapid thumping, like a really muffled motorbike type of rapid thumping. Is that abnormal? I've always ever heard the buzz of an electric motor, never a thumping type of sound. I have no idea whether or not the restrictor is in there. I could check hopefully over the weekend. Could I just take those hard lines off and try to pass some liquid through one (hold the line vertically, pour liquid in the top) and see if one flows less? It usually does read around 13 or 14, and I haven't noticed any correlation between the differences in voltage and the bogging. The volt meter has ticks at 12 and 16, so I can really only guess the values, but still. There seems to be a mild inconsistency in the voltage. The alternator was replaced with a rebuilt 280zx unit a year and a half ago, so I would assume it's in OK condition. I'll see if I could do that this weekend, though it may have to wait till next. Would trying to get an idea of flow rate be a good way to test the pump? Like time how long it takes to pump out a gallon then figure out the GPH based o that?

Heres the fuel pump, which after some research I think may be the root of the problem. I looked up the pump and it has a flow rate of between 23 GPH and 32 GPH, which sounds quite low to me. On top of that, the inlet/outlet are 1/8" fittings, which seems quite small. Plus it would explain why the bogging happened more after hooking up a return line. Previously, the fuel could only go to the carbs, whereas now it has a place to escape. The wiring shouldn't be an issue as the entire car was properly re-wired in March. Theres a fuse on the fuse panel, as well as an internal fuse in the pump, at least according the the Facet website. Heres the new routing of lines and the FPR: The line that appears to be coming/going off the right side of the first photo is the brake booster vacuum line, not a fuel line. The fuel filter is the round matte grey can in the second pic. The fuel pressure gauge was reading ~2.5 PSI when I took the photos, which was about 20 minutes ago, and the pump hasn't been on since Sunday evening/ Maybe the gauge just needed to "break in" somehow, which I've never heard of a gauge needing to do but it would explain why it read nothing over the weekend. I haven't checked float level, but I could do that next weekend (hopefully). The stock volt meter is still in the car, but I can' say how accurate it is. It seems to red between 12 and 14 volts depending on the day. One thing I can say about the electrical stuff is that when ever the car bogs and I kill the engine, I have the star the car by letting the clutch out. If I try to start it using the starter with the clutch in, it sounds as though the battery is dead. I have no idea why it does that, the battery is new, wiring is new, and the car starts just fine after sitting for a week and a half (Longest I've left it dormant since the rewire). Right now I'm thinking the most likely issue is the fuel pump. I plan to and have started buying stuff to completely re-do the fuel system, so I could just focus on getting a new pump right now rather than after all the fittings and lines.

The grey pump (#1) is a low pressure deal to fill the surge tank (#3), and the red (#2) pump is a high pressure deal to feed the fuel rail. There should be filters in there, either an in tank strainer type thing (which may be what #7 represents) or an inline type. You should have a pre-pump one for larger particulate as well as something post pump to catch smaller stuff that could clog up injectors or the regulator. Depending on what fuel pressure regulator you buy (or have bought), the position of the regulator (#6) may change along with how the feed for the rail and the feed for the regulator are set up. Does this help?

Yep, I have the set up like a stock carb fuel rail, just with hose rather than hardline. The fuel pressure regulator is set to 3.5 PSI right now, it was at 3 when I was driving.

Theres a filter in there before the carbs, but yes, thats how everything is plumbed up.