How do you know when a Mechanical fuel pump is going???
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
How do you know when a Mechanical fuel pump is going???
How do you know when a Mechanical fuel pump is going or breaking...does it just go or die slowly???
Last edited by xgtharo86x; 12-28-2006 at 07:13 PM.
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Car: 88 Firebird - SOLD!
Engine: 2.8L
Ahh, the good old days of mechanical fuel pumps - 1hr to change, ~$15 to replace & a crankcase full of gas when they went bad!
If it's a simple diaphram pump, when the diaphram begins to fail, you may notice gas stains around the vent hole on the pump and/or the oil level rising in your crankcase. When the diaphram fails, some gas will get pumped to the Carb & some will get pumped into the Oil pan.
Corky
If it's a simple diaphram pump, when the diaphram begins to fail, you may notice gas stains around the vent hole on the pump and/or the oil level rising in your crankcase. When the diaphram fails, some gas will get pumped to the Carb & some will get pumped into the Oil pan.
Corky
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
thanks im gunna go sniff my oil right now lol
#5
We really didn't need to see all the self-incriminating, sordid details. Some things are better left unsaid.
You might not necessarily get fuel in the oil if the pump valves fail on a three-line pump, and all the fuel returns to the tank. If you are suffering fuel starvation, the pukmp is one suspect, the in-tank strainer is another, the fuel filter is yet another, then there's always the float and inlet needle/seat.
You might not necessarily get fuel in the oil if the pump valves fail on a three-line pump, and all the fuel returns to the tank. If you are suffering fuel starvation, the pukmp is one suspect, the in-tank strainer is another, the fuel filter is yet another, then there's always the float and inlet needle/seat.
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
yea i have fuel starvation the filters new how do i ajust the float etc.. on a qjet non cc
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Car: 86-FireBird
Engine: -MPFI
Transmission: T5
Axle/Gears: 3:42
I dunno if its even realtive but you could plug the return line if it is a 3 line pump. Everyone does it with no side effects. I did it not that long ago and notice an improvement in umph. Id probably just get a regular 2 line if I get a new one. Its nice to have the built in reg with a return line but only if I went electric would I worry.
How? well I just cut it near the center of the line where I had slack tied up. [got all new rubber lines] Few extra hose clamps and stuffed a rod of steel in the line to plug it. Them clampped it down well. I guess you can say I still have a bit of fuel psi flex room in the return line.
How? well I just cut it near the center of the line where I had slack tied up. [got all new rubber lines] Few extra hose clamps and stuffed a rod of steel in the line to plug it. Them clampped it down well. I guess you can say I still have a bit of fuel psi flex room in the return line.
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
its a 3 plug so im better off buying an new 1 for 15 bucks
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Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Yea, they die slowly. you'll notice that you run out of fuel at higher RPM and it'll stutter. (usually).
My setup to test my fuel pump cost more than a new pump, and only confirmed that I needed a new pump. Best just to buy the pump and be done.
My setup to test my fuel pump cost more than a new pump, and only confirmed that I needed a new pump. Best just to buy the pump and be done.
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
ya i just bought one today and put it on....its better but i think i have to ajust my float...do u know how to ajust the float on a non cc qjet
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Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Pop the top off the carb, grab your float and bend it up. Spec is something like 11/32" from toe of float to top of float bowl assembly IIRC
Floats don't bend themselves down though, so if this problem just came up, then its not the float level. Unless it started getting porous, so you could replace it - if its floating low.
Floats don't bend themselves down though, so if this problem just came up, then its not the float level. Unless it started getting porous, so you could replace it - if its floating low.
#14
If it is a high level in the bowl, it is more likely a leaking needle inlet valve or a porous/leaking float as Sonix describes, or excessive fuel pressure which is overpopwering the inlte needle valve and flooding the bowl.
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
is there anything else on the carb that i can adjust to fix the problem
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the fuel starving problem
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the fuel starving problem
Last edited by xgtharo86x; 12-31-2006 at 06:28 PM. Reason: Automerged Doublepost
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
well everything is new on the car besides a tune up on the carb besides i got it from thr junck yard and its bin doin it since then and the car almost stalls out it jerks foward and bogs down badd and when i get off the gas it comes back and hit the gas slightly its fine it only does it at wot..when im messin with the hondas lol
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the carb is clean and everthings on it and the car went to the juckyard cuz of a crash so its prob fine just needs 2 be tuned
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the carb is clean and everthings on it and the car went to the juckyard cuz of a crash so its prob fine just needs 2 be tuned
Last edited by xgtharo86x; 12-31-2006 at 10:33 PM. Reason: Automerged Doublepost
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
When it starves for fuel the bowl will not REFILL fast enough to MAINTAIN WOT. It shouldn't cause a bog but will initially run wide open then fall on its face. If this is a mechanical q-jet you've pulled off of another vehicle, what motor did it come off of?
I'd recommend a rebuild, or at least a tear down, to verify everything's good and clean inside, check float settings and that you've got the correct size primaries for your application. You also need to look at the secondaries (size/hanger), proper operation of the secondaries, A/V tension, choke pull-off and linkage, etc.
You've said yourself that it needs a tune up?
I'd recommend a rebuild, or at least a tear down, to verify everything's good and clean inside, check float settings and that you've got the correct size primaries for your application. You also need to look at the secondaries (size/hanger), proper operation of the secondaries, A/V tension, choke pull-off and linkage, etc.
You've said yourself that it needs a tune up?
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Car: 86' Trans am
Engine: 85 LG4-non cc carb(building a 350)
Transmission: Rebuilt 700R4,vette servo,2200stall
Axle/Gears: 2.73 Posi
the qjet came of of a 305 out of a 85 camaro but on another post 1 gave the vin # and its origialy from a 70s 305 i think it needs a tune up cuz the way it acts... where can i get a rebuild kit
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