1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

EMERGENCY HELP. Fuel starvation.

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Old Mar 7, 2010 | 07:55 PM
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NC EMERGENCY HELP. Fuel starvation.

Alright, Ive got massive fuel starvation. Ive replaced fuel pump fuel filter. I droped the tank also in the hopes that there was a fuel strainer in the tank. But ala there is not. Is there any tips that anyone can give me to help out. This is a major emergance. Im in North carolina but due to head back to Md This coming saturday.
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Old Mar 7, 2010 | 08:47 PM
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You running a 12A or 13B engine? Have you checked to see if the fuel pump has voltage to it? How many miles do you have on the car?
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Old Mar 7, 2010 | 09:31 PM
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If it's a 12a, then you might have clogged jets in the carb. Do some research over at www.sterlingmetalworks.com

If it's a 13b with fuel injection, then wait for an expert on that to speak up.



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Old Mar 7, 2010 | 09:36 PM
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its a 12a. Replaced fuel pump with new unit. You can clearly here it when its running. 82000 miles on odometer. I was able to look into front fuel window to check lvl. Looked like the lvl was just barly off the bottom of the glass. shell kinda start for a few seconds and then cut out. Its been going down hill all weekend and tonight it just took a crap.
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Old Mar 7, 2010 | 10:08 PM
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I think what I would do if it was me, is take the fuel line loose from the metal pipe in the engine compartment ( the one that feeds the carb from the tank ) & put a hose on it that could be directed into a bottle or container or something & turn on the ignition. See if fuel is coming out in a stream. If it isn`t, then there is a problem back towards the tank. If it does stream out, then the prob could be in the carb. That is where I would start.

Last edited by Speeder165; Mar 7, 2010 at 10:12 PM.
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Old Mar 8, 2010 | 05:41 AM
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where in NC are you located? it could be as easy as clogged fuel lines as stated above, or clogged jets, bowls out of alignment (which rarely happens). might be time for a carb rebuild if it hasn't had one in a while.
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Old Mar 8, 2010 | 08:01 AM
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I'm at Camp Lejeune right now. Here till saturday, then I'm supposed to head back. To Baltimore. The guy that I bought the car from said that he had rebuilt the carb. Idk if it was done coprrectly or not. It ran just fine coming down here and took a turn for the worse over the weekend
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Old Mar 8, 2010 | 10:47 AM
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Some things to check:

Make sure you didn't get the filter in backwards. Happens even to experienced people sometimes, and will bollux your fuel volume.

Change the fuel filter again. They're only a couple bucks & easy to change, and if your tank is seriously crapped up (as many old tanks can be) you'll clog a filter fast until it gets cleaned out.

Fuel pump pressure & volume tests from the FSM would verify if your problem is carb or delivery-system based. Needs a largeish jar to check volume, and a fuel pressure guage with t-fitting to check pressure.

Bottom-of-the-sight glass fuel-level is low; if it's that low at idle and drops further when revving, fuel's not getting into the carb.

You can check the rear bowl, too, but it takes an inspection mirror and a flashlight to see it, if your carb's not stripped.

Inspect under the car, make sure you didn't hit some debris and kink your fuel hardline - - they're exposed the whole length under the car.

See if removing your gas cap makes a difference - your vent system could be plugged and a vacuum can develop in the tank that prevents fuel delivery.

Carefully undo the banjo bolts that attach the fuel inlet to the carb, and VERY carefully pull out the round screens inside the feeds and check them (you'll need small needle-nose pliers or surgical forceps - - they are small, and fragile, and irreplaceable). If they are clogged, you won't get fuel into the needles.

There are also a pair of small screens on top of the needle valves themselves, but you have to open the carb up to get to them, and the proceure for that is best studied from the Carb Manual, not relayed in a forum msg.
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Old Mar 9, 2010 | 02:09 PM
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I was referancing another post on the fuel tank https://www.rx7club.com/showthread.p...l+tank+removal that one. It show that there is access to the pick and a screen. I pulled my tank on sunday and it dosnt look like that one. The lines are part of the tank and the only holes are for the sending unit and the fill. So is there a filter on the pick up on 83 rx7s?
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Old Mar 9, 2010 | 02:27 PM
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Um, inside the tank....
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Old Mar 9, 2010 | 02:50 PM
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Are you sure its actually starving for fuel? Do you have an a/f gauge that's telling you this? Or are there other signs that it's actually a lack of fuel? But yeah, do everything DivinDriver said, that post is golden, and let us know. It's a shame I'm on the other side of the nation, ha ha I have 3 good nikki carbs and a set of fuel hardlines from the tank to the engine bay, and a clean tank. We could just swap stuff into your car after testing them...
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Old Mar 9, 2010 | 03:16 PM
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Originally Posted by Kentetsu
Um, inside the tank....
If there is how do you get at it???
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Old Mar 9, 2010 | 03:20 PM
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Originally Posted by theNeanderthol
Are you sure its actually starving for fuel? Do you have an a/f gauge that's telling you this? Or are there other signs that it's actually a lack of fuel? But yeah, do everything DivinDriver said, that post is golden, and let us know. It's a shame I'm on the other side of the nation, ha ha I have 3 good nikki carbs and a set of fuel hardlines from the tank to the engine bay, and a clean tank. We could just swap stuff into your car after testing them...
dang that would help a lot. Im pretty sure its fuel starvation. All signs point to it, Well pretty sure
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Old Mar 9, 2010 | 03:58 PM
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Ok cool. Well if the carb was rebuilt recently, you can pull it apart easily without worrying about stuck bolts and tearing gaskets like you normally would. So if you read through sterling's webite and pull the thing apart, you can probably rule out anything internal. After you've ruled out everything between the tank and engine bay, anyway...
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Old Mar 9, 2010 | 04:44 PM
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Originally Posted by theNeanderthol
Ok cool. Well if the carb was rebuilt recently, you can pull it apart easily without worrying about stuck bolts and tearing gaskets like you normally would. So if you read through sterling's webite and pull the thing apart, you can probably rule out anything internal. After you've ruled out everything between the tank and engine bay, anyway...
Absolutly, The problem right now is getting access to the car. Its a buddys thats like 35 miles away from were i am right now, So its hard to cordinate to get over there. I do hope to be working on it tommorow. Gonna do the jar test to see how much fuel is being pumped. If that checks out into the carb it is. Ordered a rebuild kit through napa. Itll be here tommorow. So that will help out too.
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Old Mar 9, 2010 | 05:02 PM
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I would pour some seafoam into the carb and see if that helps first.

If the F/A screw was messed with it might need readjusted.
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Old Mar 9, 2010 | 05:20 PM
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Originally Posted by DivinDriver
Some things to check:

Make sure you didn't get the filter in backwards. Happens even to experienced people sometimes, and will bollux your fuel volume.

Change the fuel filter again. They're only a couple bucks & easy to change, and if your tank is seriously crapped up (as many old tanks can be) you'll clog a filter fast until it gets cleaned out.

Fuel pump pressure & volume tests from the FSM would verify if your problem is carb or delivery-system based. Needs a largeish jar to check volume, and a fuel pressure guage with t-fitting to check pressure.

Bottom-of-the-sight glass fuel-level is low; if it's that low at idle and drops further when revving, fuel's not getting into the carb.

You can check the rear bowl, too, but it takes an inspection mirror and a flashlight to see it, if your carb's not stripped.

Inspect under the car, make sure you didn't hit some debris and kink your fuel hardline - - they're exposed the whole length under the car.

See if removing your gas cap makes a difference - your vent system could be plugged and a vacuum can develop in the tank that prevents fuel delivery.

Carefully undo the banjo bolts that attach the fuel inlet to the carb, and VERY carefully pull out the round screens inside the feeds and check them (you'll need small needle-nose pliers or surgical forceps - - they are small, and fragile, and irreplaceable). If they are clogged, you won't get fuel into the needles.

There are also a pair of small screens on top of the needle valves themselves, but you have to open the carb up to get to them, and the proceure for that is best studied from the Carb Manual, not relayed in a forum msg.
Listen to DivinDriver. Check/replace your fuel filter again. Make sure you put it in correct. If it ran fine and degraded over time, it sounds like a clogged filter. They're cheap and easy to replace.
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Old Mar 9, 2010 | 09:29 PM
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Originally Posted by whitey85mtu
Listen to DivinDriver. Check/replace your fuel filter again. Make sure you put it in correct. If it ran fine and degraded over time, it sounds like a clogged filter. They're cheap and easy to replace.
The filter was replaced wednesday the 3rd of this month. after replacing the filter still had the prob of it not going over 85 for some reason, Ill pick up another one
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Old Mar 10, 2010 | 01:39 AM
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check your plugs ... there's your AFR ... if they're all white then its leaning out ... if they're pitch black its rich. Clean or replace the plugs if its the second case. For all you know it could be an ignition issue also.
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Old Mar 10, 2010 | 05:41 AM
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already checked plugs, She running right where she should be when shes runnin, If you compare the plugs to a diagram it show that they have fuel additive deposits which they say is right next to normal
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Old Mar 10, 2010 | 08:26 AM
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What were the original symptoms? What is it exactly that led you to believe that this is a fuel starvation issue?
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Old Mar 10, 2010 | 12:46 PM
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Originally Posted by Verneuil
If there is how do you get at it???
the internal filter is a cylindrical shaped screen that the pickup tube runs through. you have to remove the pickup assembly on the top to the tank to check it. have you remove the feed line from the carb, insterted it into a jar and cranked the engine to see how much fuel is getting to the engine? i woud be doing this right away. if you are getting a good amount of gas to the carb, the issues COULD be misadjusted floats or a sticking float. usually if a carb rebuild is not throrough and if the jets are not removed, when cleaned, some of the sediment can recollect in the jets and clog them partially or fully, making the engine hard to start, stumble, and not accelerate. the floats must be adjusted properly and the float bowles must be spotless. you can easially pull teh air horn for an inspection of the floats and the float bowles.
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Old Mar 10, 2010 | 07:35 PM
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When i bought the car it seemed to run fine. The first time i tried to see how fast i could get it it would get up to about 80-85 and loose all power, Start to miss and what not. THought it was the timing. But when i got down here to NC it all got worse. It start losing power at 60. Then it went to 40 and then coput. Ill do the fuel test, Soon. Havnt had access to the car at all. Gonna get it towed to a house much closer and with some tools to fig this out. Ill keep ya posted. And thank you all for ur words of wisdom
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Old Mar 11, 2010 | 01:21 PM
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Just curious ... what's in your exhaust system? Stock catalytic converters still on? Maybe they're really clogged?
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Old Mar 11, 2010 | 08:40 PM
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Originally Posted by dj55b
Just curious ... what's in your exhaust system? Stock catalytic converters still on? Maybe they're really clogged?
HEHE nothing all gone, Its running. It purrs like a kitty and screams well like a rotary Carb was not the problem, Still gonna rebuild a spare one i have, Maybe polish it to a shine But thank you all for ur words of wisdom
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