FPR/Fuel Pump "Clicking/Tapping"
11-06-10, 10:49 PM
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Jolly Green Giant
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FPR/Fuel Pump "Clicking/Tapping"
Well I decided to finally get the car running again after a month or so ciesta of being frustrated with it and got a $15 Mr.Gasket Fuel Pressure Gauge because the Autometer one that came on my car was broken so I could finally just set the Fuel Pressure with accuracy better than "uhhhh...yeea....ummm...I think its....no...."
So please take a look at everything below and let me know if you have heard of this problem before or could give me some insight as to what could cause the problem. I did a quick search and found this question had been asked back in 2008 with the same symptoms but both topics were not answered.
Vehicle and mods related
'84 GSL-SE
5+6 Ports Sleeves Removed
All emissions and related components removed
Dellorto 48 DHLA w/ Fuel Pressure set to 3psi using said Mr.Gasket 0-15psi Gauge. [float levels have been checked and rechecked but I do believe new floats might be in order at some point]
Mallory 4309 FPR w/ vaccum line attached for idle pressure reduction
Brand New WIX Filter [replaced before car sat for 1 month]
Stock Fuel Pump
MSD w/ 8mm wires on leading
Stock Trailing
E-Fan
FC Fuse Block [spent all day today checking wires and the fuse block connections to make sure nothing was loose or corroded]
Autometer Narrowband A/F Gauge [just to use for ballpark figures]
Symptoms
1. If I screw in the adjuster for the FPR above 3psi the pressure jumps to about 12psi and starts bouncing back and forth between 4 and 12 irratically and a clicking sound can be heard from the FPR I guess smacking the bottom and top of the FPR body as well a similar noise can be heard from the fuel pump at a rate of about 120bpm.
2. cannot put more than 1/4 throttle into the car in any gear above 2nd even if you lean into it reeaaaallll slow. [a/f gauge pegs lean] but if you rev it in neutral with the clutch in it's fine as well as pumping the pedal with the car off you can hear the accelerator pump squirting]
3. cannot drive uphill in anything above 2nd gear with a reasonable load like 3rd gear at 35mph it cuts out after about 30 seconds going up a slight hill. [a/f gauge pegs lean]
4. the car will begin to cut out and subsiquently I shut it off roll off the street onto a flat place, give it a second and it starts right back up. [a/f gauge pegs lean]
My Hypothesis
1. Fuel Pump is ready to kick the bucket, and it sounds like it's not quite as loud as it used to be [stripped interior so I can usually hear it humming before starting the car] as well this is while supplying the required 3psi is not supplying enough fuel under load to keep the bowls full.
2. Major blockage in the fuel pickup or lines but doesn't really explain the spastic pressure increase and drop.
Current Plans
1. Going to order a Carter GP4600HP Fuel Pump [8psi @ 100GPH]
2. If this [1] does not alleviate the problem drop the fuel tank, disconnect all lines, and try to blow out, clean out the lines and inspect the tank for sludge/gunk blocking the pickup.
So please take a look at everything below and let me know if you have heard of this problem before or could give me some insight as to what could cause the problem. I did a quick search and found this question had been asked back in 2008 with the same symptoms but both topics were not answered.
Vehicle and mods related
'84 GSL-SE
5+6 Ports Sleeves Removed
All emissions and related components removed
Dellorto 48 DHLA w/ Fuel Pressure set to 3psi using said Mr.Gasket 0-15psi Gauge. [float levels have been checked and rechecked but I do believe new floats might be in order at some point]
Mallory 4309 FPR w/ vaccum line attached for idle pressure reduction
Brand New WIX Filter [replaced before car sat for 1 month]
Stock Fuel Pump
MSD w/ 8mm wires on leading
Stock Trailing
E-Fan
FC Fuse Block [spent all day today checking wires and the fuse block connections to make sure nothing was loose or corroded]
Autometer Narrowband A/F Gauge [just to use for ballpark figures]
Symptoms
1. If I screw in the adjuster for the FPR above 3psi the pressure jumps to about 12psi and starts bouncing back and forth between 4 and 12 irratically and a clicking sound can be heard from the FPR I guess smacking the bottom and top of the FPR body as well a similar noise can be heard from the fuel pump at a rate of about 120bpm.
2. cannot put more than 1/4 throttle into the car in any gear above 2nd even if you lean into it reeaaaallll slow. [a/f gauge pegs lean] but if you rev it in neutral with the clutch in it's fine as well as pumping the pedal with the car off you can hear the accelerator pump squirting]
3. cannot drive uphill in anything above 2nd gear with a reasonable load like 3rd gear at 35mph it cuts out after about 30 seconds going up a slight hill. [a/f gauge pegs lean]
4. the car will begin to cut out and subsiquently I shut it off roll off the street onto a flat place, give it a second and it starts right back up. [a/f gauge pegs lean]
My Hypothesis
1. Fuel Pump is ready to kick the bucket, and it sounds like it's not quite as loud as it used to be [stripped interior so I can usually hear it humming before starting the car] as well this is while supplying the required 3psi is not supplying enough fuel under load to keep the bowls full.
2. Major blockage in the fuel pickup or lines but doesn't really explain the spastic pressure increase and drop.
Current Plans
1. Going to order a Carter GP4600HP Fuel Pump [8psi @ 100GPH]
2. If this [1] does not alleviate the problem drop the fuel tank, disconnect all lines, and try to blow out, clean out the lines and inspect the tank for sludge/gunk blocking the pickup.
11-07-10, 03:41 PM
#3
Jolly Green Giant
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That is looking to be part of the plan, after thinking about it some more it has come to my mind that one of the lines could possibly be either sucking in air or collapsing causing the pressure to rapidly increase/decrease but this would also have to be between the tank and the pump inlet as that's the only place there is a vacuum and any line under pressure would leave a fuel leak and subsequent smell to which there currently is none.
11-07-10, 05:42 PM
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Took a video of me adjusting the FPR and it seems that the spring that goes between the adjuster and the diaphragm is what's bouncing around allowing the fuel pressure to dance.
And by the line that I say "is slapping itself against the body" it's the hardline that passes above the fuel pump and goes up over the axle before turning into a soft line.
http://www.youtube.com/watch?v=SL6_goCaqMk
This began to occur during pre-start conditions when there is no vacuum present as well has never been an issue until recently and I've had the vacuum line on there for I would imagine almost a year now without incident but I will look into it, I thank you for the info.
As shown in the video it holds a near constant pressure with the spring removed but the second I put it back in it goes crazy, perhaps a stiffer spring might solve the problem or no spring at all?
And by the line that I say "is slapping itself against the body" it's the hardline that passes above the fuel pump and goes up over the axle before turning into a soft line.
http://www.youtube.com/watch?v=SL6_goCaqMk
As shown in the video it holds a near constant pressure with the spring removed but the second I put it back in it goes crazy, perhaps a stiffer spring might solve the problem or no spring at all?
11-07-10, 06:37 PM
#6
Interesting. I've never seen an FPR act like that. My first thought would be a bad FPR but in the vid it appears to be working, quite well in fact. I have 2 suggestions but both are basically guesses based on what I know about fuel systems. 1. There is a partial clog in a fuel line Not sure if it's in the supply or return side but I would start with the supply side, beginning with the fuel pickup in the tank. 2. There's a leak in the supply side between the tank and the fuel pump and the pump is sucking air along with fuel.
I had such an air leak on the widebody at one time. It was the metal fuel line between the tank and fuel pump that's bolted to the back of the storage bin. The line had the tiniest pin hole leak from rusting where it was in contact with the sheet metal. Had to remove the line to even find/see the spot.
Out of curiosity, Will the engine run with the spring removed from the FPR? If it does, what's the readings on the FPG?
I had such an air leak on the widebody at one time. It was the metal fuel line between the tank and fuel pump that's bolted to the back of the storage bin. The line had the tiniest pin hole leak from rusting where it was in contact with the sheet metal. Had to remove the line to even find/see the spot.
Out of curiosity, Will the engine run with the spring removed from the FPR? If it does, what's the readings on the FPG?
11-07-10, 06:52 PM
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Jolly Green Giant
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Interesting. I've never seen an FPR act like that. My first thought would be a bad FPR but in the vid it appears to be working, quite well in fact. I have 2 suggestions but both are basically guesses based on what I know about fuel systems. 1. There is a partial clog in a fuel line Not sure if it's in the supply or return side but I would start with the supply side, beginning with the fuel pickup in the tank. 2. There's a leak in the supply side between the tank and the fuel pump and the pump is sucking air along with fuel.
I had such an air leak on the widebody at one time. It was the metal fuel line between the tank and fuel pump that's bolted to the back of the storage bin. The line had the tiniest pin hole leak from rusting where it was in contact with the sheet metal. Had to remove the line to even find/see the spot.
Out of curiosity, Will the engine run with the spring removed from the FPR? If it does, what's the readings on the FPG?
I had such an air leak on the widebody at one time. It was the metal fuel line between the tank and fuel pump that's bolted to the back of the storage bin. The line had the tiniest pin hole leak from rusting where it was in contact with the sheet metal. Had to remove the line to even find/see the spot.
Out of curiosity, Will the engine run with the spring removed from the FPR? If it does, what's the readings on the FPG?
I will pull all the lines off on Tuesday and check them all out including the cradle where the fuel pump is as well as all the lines and stuff, get some new crush washers and such and see if I can find any other evidence of leaking.
I haven't tried running the car without the spring in it but it will be something for me to try on Tuesday as well and unfortunately at the moment I am not able to connect the FPG into the FPR [currently running it off the line to the carb] itself because it's a 1/8 NPT and the ports are 3/8 NPT. I had no luck finding a reducer here in town over the weekend so I will stop by a specific Fasteners place on Tuesday which if they don't have it then I'll just have to find it online [I know Summit has it but $6+ shipping is ridiculous] considering their hhhuuuuggggeeee inventory.
And last if these fixes don't help I'll get a container, drain whatever fuel is in there and crack the tank open for inspection, it's the last thing I want to do right now but 26 years of driving and filling....I can't say I'd be surprised to find some goop and grime in there.
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11-07-10, 07:01 PM
#8
Have you check the plumbing section at the hardware/home center stores for the 1/8-3/8" bushing? Any store with a decent inventory of brass gas, (natural), fittings should have it. I get all mine at Ace Hardware, never had a problem finding the needed parts.
11-07-10, 07:08 PM
#9
Jolly Green Giant
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O'Riellys even had the correct bushing but I couldn't thread it on more than about 1/4" before it stopped so I assumed it was the wrong type of threading and the bag didn't specify the type beyond the size so I headed to Home Depot.
11-07-10, 08:50 PM
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Jolly Green Giant
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Yea I think all the lines [pump, return and vent] are all soft between the tank itself to where the cradle of the pump is so I can think of atleast 1 line where some air could be sucked in, just really gonna have to check the fuel filter and figure out how that thing is leaking cuz I recall making sure that thing was torqued down correctly.
11-07-10, 09:07 PM
#15
An NPT fitting in those small sizes may not thread more than 1/4". Add a little fuel resistant thread sealer and you should be good. Skip the worm drive clamps, they tend to chew up the hose and the cheaper ones, (WalMart), have a high failure rate. Spend the extra bit on the FI rated solid band clamps.
11-09-10, 02:42 PM
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Jolly Green Giant
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Well I found a pretty good deal on a Holley Red through Autozone so I won't have to wait for a week or so to get it from Jegs or Summit and its about $108 with tax so no shipping etc.
With the money left over I'll see about picking up some new lines and possibly just some new "corbin" clamps, they are the same type that Mazda used from the factory like on the vacuum lines for the brake booster and such, any thoughts? FI Clamps seem to be pretty expensive considering I'm gonna need 6-10 of them.
With the money left over I'll see about picking up some new lines and possibly just some new "corbin" clamps, they are the same type that Mazda used from the factory like on the vacuum lines for the brake booster and such, any thoughts? FI Clamps seem to be pretty expensive considering I'm gonna need 6-10 of them.
11-09-10, 04:25 PM
#18
FI clamps are pricey, sometimes running 89 cents apiece, but then the fuel system is not the place to compromise on cheap parts. I started using them because I had too many worm clamps failing and planned to go FI later on. It's just like the FI fuel line @ 3+ times the cost of low pressure fuel line. Learned something new. Didn't know the stock clamps had a name.
11-09-10, 07:23 PM
#19
Jolly Green Giant
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FI clamps are pricey, sometimes running 89 cents apiece, but then the fuel system is not the place to compromise on cheap parts. I started using them because I had too many worm clamps failing and planned to go FI later on. It's just like the FI fuel line @ 3+ times the cost of low pressure fuel line. Learned something new. Didn't know the stock clamps had a name.
Not the right size but: http://www.napaonline.com/Search/Det...302_0293958717
I'll just have to make a trip down to NAPA and look because their website is kind of a PITA to search through.
I guess these are the FI clamps you speak of?
http://www.napaonline.com/Search/Det...227_0006394100
As well from reading a few install topics and some other material it was mentioned that Holleys are best mounted vertically, does this hold any weight?
At this point I don't much care how noisy the car is as its more of a fun car and with no interior, and a stupidly loud exhaust at the moment I guess I'll just mount it on the outside of the storage bin with a cut up mouse pad or some rubber to provide a tiny bit of insulation like this:
11-09-10, 07:48 PM
#20
Your link goes to the opening search page on NAPA. The FI clamps are a solid band with a nut and machine screw. Yes, many pumps need to be mounted vertically, Holley, Mallory and Carter in particular . Mines mounted on the back of the bin. I made a bracket plate so the pump is mounted in the vertical, not at the angle of the back of the bin.
11-09-10, 11:21 PM
#21
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Is the regulator rated for the pressures that the pump is putting out? Trying to get a FI pump reduced to the pressures you need is going to be tough. You might want to consider something like a Carter. I put together a writeup, which is in the Archive section, if you want to check it out.
Also, that gauge was a waste of money. There are not many gauges that will read anything near accurately at those pressures. The only one that has been proven to be accurate that I am aware of is from www.re-speed.com
.
Also, that gauge was a waste of money. There are not many gauges that will read anything near accurately at those pressures. The only one that has been proven to be accurate that I am aware of is from www.re-speed.com
.
11-10-10, 12:25 AM
#22
Jolly Green Giant
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Is the regulator rated for the pressures that the pump is putting out? Trying to get a FI pump reduced to the pressures you need is going to be tough. You might want to consider something like a Carter. I put together a writeup, which is in the Archive section, if you want to check it out.
Also, that gauge was a waste of money. There are not many gauges that will read anything near accurately at those pressures. The only one that has been proven to be accurate that I am aware of is from www.re-speed.com
.
Also, that gauge was a waste of money. There are not many gauges that will read anything near accurately at those pressures. The only one that has been proven to be accurate that I am aware of is from www.re-speed.com
.
The Mallory 4309 is said to be rated from 3-12psi so yes it is a struggle for it to get an FI fuel pump [fsm says 50-70psi] to 3-4psi but regardless it warrants a new fuel pump as even when it was working "perfectly fine" I was still running out of fuel at the top of 3rd from a dig, and the FSM has the stock pump rated at about 27+GPH which is already being severly limited by the regulator dropping 90% of it's pressure I can only imagine what its doing to the flow rate.
The main reason a Carter has been ex-ed from the list is simply because of my time frame, I'd like to get the car back on the road next week and I get paid on Friday allowing me to pick up a Holley Red I know of here in town same day so by Sunday I should have all the new lines in and settings stuff up to make sure I have no problems.
Now you are running a Carter GP4594
72GPH
8PSI
1/4NPT
$75.95 + Shipping
Holley Red
97GPH
7PSI
3/8NPT
107.95 + Shipping or $108 w/ Tax if I get it here.
Carter GP4600HP
100GPH
5PSI
3/8NPT
$106.95 + Shipping
Summit Racing "Street Pump" G3136-1 [though I wouldn't trust house brand for reliability]
95GPH
7PSI
3/8NPT
$79.95
Now taking all things into account:
Required Flow Rate
Fuel Line Size
Pressure
Price
Now unless there is something I am critically missing the Holley Red and Carter GP4600HP [which I was originally looking at] are in a dead heat only I can get the Holley in town thus making it the winner here.
As with diagnosing what the real cause of what this problem is I won't exactly know until the pump is switched out because frankly I can't think of anything unless the pump is somehow failing partially causing it to fluctuate the pressure and flow which is then magnified 10 fold by the FPR because as shown in the video even with the FPR spring removed it still bounces around just not nearly as much.
The pump is something I've wanted to get for a long time but has been a "well this is working for now" excuse and now I finally don't really have one since the fuel system is getting overhauled regardless and so we'll see if the pump and new lines does solve the issue, if not the FPR will be taken apart and cleaned/inspected as will the fuel tank and if need be, sent out to get cleaned.
11-10-10, 02:57 AM
#23
The Mallory 4309 is the recommended fpr for reducing FI pumps to carb fuel pressures. The added bonus is it's a rising rate fpr for use in boost applications. Seeing the vid again makes me think the fpr is going bad, though there isn't much that can fail. The spring can weaken and or the plunger can hang up. If it continues to cause problems, order a rebuild kit and make sure it's clean and debris free inside.
11-10-10, 10:47 AM
#24
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Took apart the FPR and it all looks to be clean and good, messed around with some other stuff as well and upon sitting under the car for about 10 minutes listening and moving stuff around you can hear the pump fading in and out with the ripple in pressure so just leads me further to the point of just replacing the pump and going from there.
11-16-10, 08:04 PM
#25
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Attempted to drive the car to work today and nearly didn't make it, the fuel pump is randomly cutting out and leaving me with near or empty bowls causing issues.
As well I took apart my jets today to see if anything was blocking them because aside from being able to rev the car with WOT I can't get past the transition ports without it leaning out and stumbling, it turns out bits of rubber from when I was sticking the gauge into the end of the hose have made their way into the bowls and subsiquently into the jets themselves so the carb will be coming off the car on Thursday, getting throughly cleaned and blown out and hopefully will solve ONE of my problems.
Might follow through and buy that Holley Red from 81WideMariah if I can get some affairs in order so that will hopefully solve that problem, if not then I will have to look into the electrical as if the car dies out while I'm driving I'll pull over and the glass inline filter is completely empty, shut off and turn back on the car and it fills right back up.
As well I took apart my jets today to see if anything was blocking them because aside from being able to rev the car with WOT I can't get past the transition ports without it leaning out and stumbling, it turns out bits of rubber from when I was sticking the gauge into the end of the hose have made their way into the bowls and subsiquently into the jets themselves so the carb will be coming off the car on Thursday, getting throughly cleaned and blown out and hopefully will solve ONE of my problems.
Might follow through and buy that Holley Red from 81WideMariah if I can get some affairs in order so that will hopefully solve that problem, if not then I will have to look into the electrical as if the car dies out while I'm driving I'll pull over and the glass inline filter is completely empty, shut off and turn back on the car and it fills right back up.