wankelnewbie

iTrader: (2)

Hey I just got it out on the road for its first fresh tank of gas in five years. Got to the station fine (about 2 miles), started back after pumping gas fine, then about half a mile from the station it started sputtering like it was out of gas. Gas level in the from float bowl was barely up to the bottom of the sight glass, I tried manually running the fuel pump and opening the gas cap and nothing. If I let it sit a few minutes it will start back up, but die again after a few yards.

I just got done walking home and am waiting for some friends to come help drag it home, so I figured I had better post and see if anyone had any ideas. I had it idling for about 45 minutes yesterday and again this morning before I dared take it on the road. I confirmed that the fuel pump is running before I started walking. I'm thinking maybe the heat of driving caused a little vapor lock, and maybe I need to pull the return line to let the air out of the carb, but other than that idea I'm stumped.

It's an 85 with a 12A, fully stock except a autozone fuel pump I installed temporarily. And the air cleaner housing was removed for better access to the carb.

Jibaro 12A

iTrader: (8)

Have you checked your fuel filter at all?

wankelnewbie

iTrader: (2)

Yeah fuel filter is new. Actually had 2 (new ones) plumbed in, both in front of the pump (b/t the pump and the tank I mean). First thing I did was take 1 out when it died. They were both new this week and had maybe 3 miles and a couple hours of idling on them.

Jibaro 12A

iTrader: (8)

Did the carb sit with old gas in it while it was stored? Was the carb rebuilt recently?

wankelnewbie

iTrader: (2)

Had old gas throughout the system, I drained and rinsed it all with fresh, and plenty of seafoam. I figured between the seafoam and fresh gas it would have at least started to clean out any deposits in the carb. I didn't want to do a rebuild just because I would prolly screw something else up. And it ran for a few hours on fresh gas so I figured I was safe enough.

I really didn't confirm that fuel was getting to the carb, or that it had any pressure, you think I should disconnect the fuel line at the carb and make sure its flowing?

Jeezus

iTrader: (4)

Stuck needle in the front. Tap carb with screw driver and keep an eye on the front sight glass.

OneRotor

iTrader: (3)

I'm calling fuel filters. They may be new, but someone posted on here saying that the stock fuel filters can clog if you look at them the wrong way.

The reason why I'm saying Fuel Filter is this: You may have drained all the old gas out, but there is still probably some varnish at the bottom of the tank, that was knocked loose by the tank of fresh gas.

wankelnewbie

iTrader: (2)

OK guys thanks for all the posts. I just got back from running out and tring a few things. First, I disconnected the return line. Ran the pump, nothing came out after letting it go a few minutes. Disconnected the fuel line and ran the pump, just got a little trickle.

So then I pulled the last fuel filter out and hooked the pump directly to the tank. It pushed fuel out of the return line at the carb (along with some air bubbles ????), I hooked the return line back up, started the car and took off. Made it about 200 yards and it quit again. Coasted it back down the hill to where I started and locked it back up and left.

When I tap the carb, should I do this while the pump is running?

Also, is it safe to run it without a filter in its current state?

trochoid

iTrader: (6)

NO. The crud in the tank will cause the need for a carb rebuild, fresh filters first and have some spares on hand.

DivinDriver

iTrader: (15)

Sounds like pumping fresh gas into the tank stirred up all the crud that had settled in there; now it's in suspension in the gas and making it into the filter.

You'll go thru a bunch of fuel filters unless you get the tank cleaned out.

wankelnewbie

iTrader: (2)

I just pulled her home, will check it out through the week and keep it posted up here.



Yeah that's kind of the way I've cleaned out tanks in the past. There was a BUNCH of rust in there, enough to kill the brand new OEM fuel pump the PO put in. The gas coming out of the carb looks nice and clear in color now instead of this bloody brown color it had before so I feel pretty good that the dual filter setup is getting the job done. But I'm thinking that the pump (its a solenoid type pump as opposed to a rotary vane pump like stock) may have gotten hot enough to lose its prime, and having to pull through 2 filters probably isn't helping. I have some glass screen-type filters (for a buck 80 apiece from JC whitney, like 70% off, went ahead and stocked up) coming in the mail in a couple of days, I'm thinking I'll plumb in one of those in between the tank and the stock filter. Hopefully that will give a little less flow restriction, with the added advantage of being able to monitor how bad the filter is getting.

I'm also gonna dig out an old garden sprayer to put a 5/16 fitting on and fill it up with gas so I can limp home if this happens again.

Again thanks for the ideas, and keep them coming!

installer67

iTrader: (18)

Drain and clean the tank to be sure to get all remaining varnish, rust and crud. inspect soft fuel lines and or replace. use a compressor and clear the hard lines. Reconnect all and use new fuel filters. problem should be solved providing you haven't already gummed up the carb.

wankelnewbie

iTrader: (2)

I just realized I never updated this thread. I replaced the fuel filters and it still didn't work so I pulled the pump and found a bunch of junk in the check valve, blew all that out and it works fine. I rigged up a line where I pumped out of the tank, through the filters, through the pump, then back to the tank and after like 5 sets of filters and a half cup of rust it the glass filter started staying clean. I've drove it through the neighborhood a few times (maybe 20 or thirty miles total) and it has been fine. I'll get her tagged and insured before I drive her much more, but I already stuck a few sets of filters and a bulb-type primer pump (the hand pump you use on boats) in the glovebox just in case it clogs up again.

Thanks for all the help!

Kentetsu

In your shoes, this might be a very good idea: https://www.rx7club.com/1st-generation-specific-1979-1985-18/dual-fuel-filter-mod-528445/

Rather than running two filters in series, I ran them in parallel. That way, each filter only has to run at half duty. I did this a couple of years ago, and haven't had to replace a filter yet.

The problem with the stock filters is that if they clog enough to degrade performance by (at a guess) 10%, then you will experience performance issues. Running two filters the way I did, they would have to each degrade by 45% before I see any problems.





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DriveFast7

iTrader: (1)

http://www.summitracing.com/parts/FR...5&autoview=sku

wankelnewbie

iTrader: (2)

I LIKE THIS!!!! In my case running the glass filter in line with the stock filter only increases the flow resistance, so going to a parallel setup (each leg has glass and stock, if that makes any sense) really makes good sense. Mine will be sitting in the compartment behind the seat (yeah yeah not real safe :/, especially for a nicotine addict, but a leak is pretty obvious), at least until I feel pretty confident about not having to replace filter on the side of the road.

And as an added bonus, the glass filter sitting horizontally seems to always trap a little bit of air, and you can kind of see when the flow is getting slow because the bubbles don't move around as fast. With the two glass filters sitting side by side you could probably see if one leg was flowing less than the other, and know its time to go ahead and replace the filter.

I'll try and do this over the weekend and put some pics up here and on that thread.

wankelnewbie

iTrader: (2)

That's probably about where I'm headed once the tank gets good and clean and I get the pump and filters back under the car. For now having everything there inside the cabin is pretty easy to swap out.


I think that's the exact one my brother uses on his waste veggie oil powered mercedes as a polishing filter going into the injection pump.

DivinDriver

iTrader: (15)

Also, any crud particle small enough to make it through the first filter isn't likely to get caught by a second in-series filter anyway, since both'd have the same filtration specs , based on particle size.

Kentetsu

...and since each filter flows at half speed, it might even stand a better chance of grabbing those tiny bits of crud.

wankelnewbie

iTrader: (2)

Here's the setup I put in over the weekend. It doesn't clog up easy, but it still seems like I'm catching crud in the fuel pump (after the filters), cause when it died yesterday after several short trips, I unhooked the fuel line from the carb and squirted some wd-40 into the intake of the running pump, hooked everything back up, and it ran like a champ again.

I'm gonna try and get it down to about 5 gallons, then pull the tank, shake it all up real good, and dump all the gas into a bucket. I swear that's the only place there is ANY rust on this car. Gotta love the south and salt-free winters!

n8dawg

Basically sounds exactly like the prob I had with my 13b gsl-se. I wanted it done right so I took the tank to a radiator shop. Sure it cost me 135$, but i got the piece of mind knowing that there was zero rust left and everything is working great. Give me a few months and I will hit 200k on the odometer on an original engine.

Kentetsu

The problem might be that you are sucking crud up against the sock filter in the tank. Then, when you stop for a bit (to mess around with the pump, or whatever) the crud falls off the sock and she runs good again.

Getting the tank professionaly cleaned would be your best bet. But if you do it yourself, there are some tank restoration kits out there that are supposed to work pretty good (Por-51, or whatever the name is, is one of the best).

wankelnewbie

iTrader: (2)

167k on this one with original everything. I suspect that's where I'm eventually headed, but I'd like to try a couple of less-expensive alternatives first.

Good point, hadn't really considered the in-tank filter. I'll get in there this weekend and get the tank pulled, then get a real good look at things.

RustyRacer

I hope this works out for you, after I rebuilt my carb and drove it a while, I found it stopped suddenly with no fuel going into the carb. Turned out the filters above the float needle had crudded up. Cleaned them up and its been running great since.

vipernicus42

iTrader: (4)

Definitely take the tank to a cleaning place. I got mine done and it was like $50 Canadian, which is well worth the headaches it saves. Plus they re-sealed the area around my fuel level sender and fuel filler neck and touched up any spots on the outside where rock chips had eaten through the stock paint/protective coating.

Jon