slapper Posted February 27, 2007 Report Share Posted February 27, 2007 posted this on toymods - but I know there are a coupla subscribers who don't necessarily get over there, so I'll post here as well ... Well, the 32DIR on the 4K is haemorrhaging fuel (seemingly) from every available seal and partial orifice after a year of use ... well, there's a nice coating of red fuel and dirt shite all over it ... and I'm suspecting fuel pressure may be the culprit. I'm about to slap a 32/36 on the 4AC and (in addition to fixing the 4K's problem) I don't want the same issues on this one ... I have the stock 4K fuel pump pushing fuel into the weber - I think the toyota pump is in the 7-9 psi region, where as the weber probably wants somewhere around 4 based on the web meanderings I have done. So ... I've started looking for a suitable leccy fuel pump or pressure regulator, only to be confronted with so many options that I don't know quite what's what. The obvious question (of people who know more about this than I do) is "what's a suitable pump/regulator without breaking the budget?". The local SuperCheap has a Facet Posi-Flow (1.5-4 psi) for $90, autoPro want to sell me a (no-name?) Hansa FP401 (4-7 psi) for the same price with staff at both shops claiming their option as the perfect solution to my problem. What have youse people used (fuel pump, regulator)? Was it successful? How much did it cost? If I go down the fuel-pump path, wiring it up will be okay - I have the necessary knowledge concerning Circuit Opening Relays, fuses etc etc thanks, Slapper Quote Link to comment Share on other sites More sharing options...
pozman Posted February 28, 2007 Report Share Posted February 28, 2007 I'm using the bigger facet pump for my lift pump on my rolla, seems to work fine kickn5k also uses ther same pump for his twin su 5k, hes had no problems with that Quote Link to comment Share on other sites More sharing options...
styler Posted February 28, 2007 Report Share Posted February 28, 2007 (edited) i have been exactly in your situation slapper and after all the research and shopping around i can tell you the only pump i would go for is the carter 4070 rotary vane, low pressure, high volume, self priming, lift capable, 5 psi, no return, no regulator, suitable for all weber setups. problems with carby pumps is that some pump designs are crap so they doesnt have needed features, or the regulator doesnt work properly or the setup is bad. i could go through all of this tech but in the end go the carter as its the best i have found. also no $60 regulator needed. else i have had sucess with a pierburg 5 psi pump low pressure, high volume, self priming, lift capable, no return, regulator needed though ( i used a holley adjustable - $90), pump cost $90 at supercheap. i can't say i could recommend facet from all the problems people get from them. Edited February 28, 2007 by styler Quote Link to comment Share on other sites More sharing options...
Felix Posted February 28, 2007 Report Share Posted February 28, 2007 Can't say I have had problems using the stock mechanical fuel pumps. I was going to upgrade to an electric pump, but it isn't really worth the hassle unless you are going to run twin sidedrafts. I'm a strong subscriber to the K.I.S.S. principle. The only time I have had problems with weber downdrafts is if the carb has had a worn needle and seat. I'd say you most likely need to replace yours, possibly even rebuild the carb, with new gaskets and diaphrams. A needle and seat is only worth about $15. Quote Link to comment Share on other sites More sharing options...
Robert Posted February 28, 2007 Report Share Posted February 28, 2007 The mechanical pump on a K Series Delivery pressure-nominal is 25 kpa which is around 3.5 psi. Should be about the same on the 4A, so thats the right pressure for the carby. Id be more concerned with gaskets and the needle and seat before worrying about the fuel pump. Quote Link to comment Share on other sites More sharing options...
Corolla_Kid Posted February 28, 2007 Report Share Posted February 28, 2007 Yeah the stock mechanical pump keeps fuel up to my dhla dellortos's on a worked 5k. I wouldnt worry to much about it. Quote Link to comment Share on other sites More sharing options...
slapper Posted February 28, 2007 Author Report Share Posted February 28, 2007 thanks everyone - I think first thing I'll do is get a fuel pressure gauge - a wet one for use inside the engine bay, not a 'leccy in-cabin job. Dropped into Sprint on the way home to get some prices - they'll ring me back. Any body got any views on the difference between in-line and T-piece (in/out vs a single in connection)? cheers, Slapper Quote Link to comment Share on other sites More sharing options...
MRMOPARMAN Posted February 28, 2007 Report Share Posted February 28, 2007 if you have too much pressure going into the webber, then you will want to look for a pressure regulator, not another pump. I'm not sure about your webber, but DCOE's and IDA's like about 2-4psi, and pretty much every unregulated pump in the known universe will outpump that figure, so what ever pump you get you will need a reg on that too. id just throw a reg on a stock pump. its a bit safer using the mechanical pump if you blow a fuel hose anyways! Quote Link to comment Share on other sites More sharing options...
Felix Posted March 1, 2007 Report Share Posted March 1, 2007 The stock mechanical pumps have an inbuilt regulator, preset at 3.5 psi +/- 0.7 psi. Keep in mind that any non-return style regulator will have a pressure variation like this. The only way to have constant fuel pressure is to run a return style regulator, and/or a pump with an internal bypass. There are some later stock mechanical pumps that do run a return/bypass line back to the tank. For the cost of a pressure guage you could probably just about buy a carby kit. The first thing I would have done is to examine the needle and seat for wear... ten minute job. :P Does the idle falter/load up if you pull up real quick at a set of lights? This is the classic symptom of the needle and seat being overun due to it being worn. Quote Link to comment Share on other sites More sharing options...
slapper Posted March 4, 2007 Author Report Share Posted March 4, 2007 (edited) sorry for the tardy reply ... I've been at the Clipsal getting beer and sunburn :P Car has been off the road for a while now (must be nearly two years I would think by now - my how time flies!), but I don't recall any problems coming off throttle. Looking at the back of the car, there does seem to be a larger than appropriate evidence of soot, but apart from that, the shite all over the carby is all I've really noticed. Something somebody said prompted me to think along the lines of the stock 4K fuel pump putting too much pressure into the weber - that's why I asked the original (what fuel pump/regulator are people using) question ... so far I haven't really had a definitive, unequivocal answer to the question "is the stock fuel pump okay with a 32DIR downdraft?". I've had: I've had no problems with the stock pump I've had no problems with a facet I've had no problems with a no-name electric what you should run is a regulator what you should run is a carter 4070 what you should run is a facet no matter what you do, you're going to need a regulator as you can see ... no clear way forward from the advice I've received so far! so - pressure gauge before I even think of replacing the stock mechanical pump so I have a starting point to work from. I'll let people know how I go ... but I've blown my pocket money for this month and possibly next, so this is not likely to be a quickie! cheers, Slapper Edited March 4, 2007 by slapper Quote Link to comment Share on other sites More sharing options...
Robert Posted March 4, 2007 Report Share Posted March 4, 2007 The stock pump is ideal for your setup, i recommend you use it and put a kit through your carby and and a new needle and seat. :P Quote Link to comment Share on other sites More sharing options...
Taz_Rx Posted March 6, 2007 Report Share Posted March 6, 2007 Ok, you want definate answers,...here you go. Don't want to sound like a know it all but I am 100% certain on what I am about to tell you correct. Trust me I have had several different types of fuel systems in both of my cars. Firstly, a small down draft weber needle and seat will actually hold up to 15-16psi psi!!!!...........so the pump is NOT getting too much pressure. as robert said, a stock 4k pumps makes around 4psi So with those 2 above statements,.......if the needle and seat is not holding the pressure, it does need replacing. The ideal fuel pressure for a carby like that is around 7psi. The needle and seats in small downdrafts are the same thread and therefor interchangable. so any fiat, alfa, corty, falcon, etc needle and seat will be suitable. I actually have a Falcon 4.1lt needle and seat in my Fiat 1.3lt weber as an upgrade. and, if its leaking out of the gaskets,......pure and simply the carby needs a re-kit. I would recommend buying a fuel pressure guage for under the bonnet, they prove very hand. I have a pic of my speco one in my projects thread, they cost $15 from Burson. If you do decide to upgrade the pump to an electric after market one then I would highly recommend a Carter for the reasons mentioned above - Low pressure, high volume, self priming etc. heres a list of available Carters. Model number, flow, psi, and RRP. 60430: 30GPH, 4-6psi, Universal Inline Gerotor type - $86 4070: 72GPH, 4-6psi, Competition Series 72 GPH - $152 (Carter green) 4594: 72GPH, 6-8psi, Competition Series 72 GPH - $166 4600HP: 100GPH, 6-8psi, Competition Series SILVER pump - $151 4601HP: 100GPH, 14-16psi, Competition Series BLACK pump - $188 so as mentioned the 4070 (commonly reffered to as a carter "green") is the one for you. and because of its pressure range and the tolerance your needle and seat should have you don't actually have to run a regulator. so the statement of "no matter what you do, you're going to need a regulator" is absolutley false!!!! I actually used to run the Carter black (14-16psi) on my weber with NO REG AT ALL and the weber still held the pressure. Think thats about it. If you have any more q's, just ask. :P Quote Link to comment Share on other sites More sharing options...
Robert Posted March 6, 2007 Report Share Posted March 6, 2007 I also ran a carter black into a 32/36 with no problems at all. :P Quote Link to comment Share on other sites More sharing options...
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