I inherited a real problem with this 4.9 swap eating fuel pumps at an alarming rate. The last one I had professionally installed and it only lasted a month. I think that makes number 5. I've been told that it could be a problem with a restricted fuel line or a possible electrical problem. I've been through everything possible that would be electrical including rewiring with new wires from the tank to the connector on the firewall, new relay, had the chip reprogrammed and fixed a bad splice after the firewall connector. I'm thinking it may be the fuel lines and since I'm not really too happy with the way the stock V6 routing runs so close to the belt pulleys, I've decided that I may as well eliminate the fuel lines as a source of the problem by just replacing them all. I was told that the metal fuel lines from an iron duke will solve part of the routing problem so I pulled a set off an old parts car I have and took a look at how well they would fit. It looks like they will work and route the fuel over the top left of the motor which is exactly what I was looking for. Forgot to mention I have also replaced the fuel filter. Car is an 85 with a 93 4.9, Ed Parks harness.
2 questions, has anyone done this and if so any tips, tricks or pictures?
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[This message has been edited by paulcal (edited 08-17-2014).]
I used the 4 cylinder fuel lines on my 4.9 Formula. No problems, but oil filter access is somewhat restricted. The fuel filter was moved to the driver side of the engine compartment down low, similar to the V-6 location. Sorry, I don't post pictures.
I had custom flex lines made up (stock 4 cylinder lines from the tank to the filter) - custom lines both from the fuel filter area to the rails. Also had done a V6 car same ideal but obviously the custom lines ran from the fuel filter along top the frame rail and up to the injector rail. Never a fuel pump problem on any of the cars. IIRC the total cost was about $150 for both lines and fittings (Hose Headquarters - a local hose shop).
[This message has been edited by Mickey_Moose (edited 08-18-2014).]
Thanks Double M for the pic. How did you route the lines around the exhaust manifolds?
Since this has been an ongoing issue I've decided to start at the fuel tank and just replace every single inch of fuel line and the pump, maybe even the tank sending unit. I have a V6 parts car I can get the sending unit from. I guess I also need to get a reading on the voltage to the fuel pump to see if that may be an issue. As far as I can see, that's the only two issues it can be that's causing it.
Got the car up on jack stands today so I could get a good visual inspection of the fuel lines and wiring. While I was at it I also gave any wires that I could see with butt splices on them a good tug. I discovered a couple of issues that are in need of addressing. 1st was during the tug test. The battery wire that goes to the terminal below the C-500 came apart at the butt splice when I pulled on it. I bought some waterproof shrink wrap butt splices and got that back together. 2nd is what I believe to be the fuel supply line going to the injector rails has a nice kink in it at one of the 90 degree bends going up into the engine compartment below where the battery tray was. While I was at the parts store picking up a couple of items, the counter guy told me that the local Napa will custom make SS braided lines. Sweet. My plan is to buy some hard lines and run the fuel lines up the drivers side of the firewall and then come straight across the left side of the engine, in front of the distributor, over the oil filter and around to the inlets. That looks to be the best routing to keep it as far away from the exhaust manifolds and cross over possible. I'm not sure how much of it I'm going to have as braided line but it seems like from the firewall across to the inlets would look the best. My overall plan is to reduce rubber hoses to an absolute minimum since they tend to fail internally with no indication of failure. There's way too much rubber fuel line on this machine as it sits now. The pic is of the kinked fuel line.
[This message has been edited by paulcal (edited 08-25-2014).]
Butt connectors? Booo! Solder and heatshrink! Yea!
You could consider a fuel line path along the right side lower frame rail, up the rear of the strut tower and across the rear valve cover to stay away from the exhaust.
Butt connectors? Booo! Solder and heatshrink! Yea!
I second this, if you don't know how it's time to learn, those but splices, even the sealing ones are junk. I've used them temporarily but just to get things sorted out and tested before soldering.
I'm aware of the limitations of butt splices but I just needed a quick solution until I can get the other problems solved then I can revisit the wiring. I would much rather trust a soldered splice myself. I got the 96 Vette pump ordered yesterday so tomorrow I'll drop the tank and start on the new hard lines for the fuel system. Once I get those bent and installed I can grab some measurements for the braided lines.
The stock 2.8 fuel pump is the same pump that Cadillac used in the 4.9 cars.....why the Vette pump?
In researching the problem I ran across the '96 Vette pump as a direct replacement. It would basically be a hi performance upgrade from stock. I've been through so many stock pumps that I figured it certainly couldn't hurt.
I did climb under the car today and dropped the tank. While I was under there, I also removed all the fuel lines from the tank to the engine inlets. The supply line from the filter to the engine was in worse shape than I thought. It looks like it was bent by hand in two places and one of the 90's was virtually collapsed in the center. The other spot wasn't as bad but I'd be willing to bet that between the two there was some serious flow restrictions causing the pump to work twice as hard and causing the premature failures. Once I get the new pump installed and the tank back in place I'll run some stainless braided line from the filter to the inlet up the left side of the engine bay. I'm not even going to mess with the '84 fuel line.
What brand fuel pumps are you using? There are good pumps out there but also a lot of Chinese garbage as well. Ebay is full of AC Delco and Walbro counterfeits. AFAIK there are few if any American made fuel pumps. That is why I use Bosch pumps. Made in Brazil but in their own factory that applies company manufacturing and quality standards. Bosch P/N 69225 seems to work for all the swaps that I've done. As stated earlier in this post, poor wiring connections or restricted connections will burn out a fuel pump.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 09-01-2014).]
What brand fuel pumps are you using? There are good pumps out there but also a lot of Chinese garbage as well. Ebay is full of AC Delco and Walbro counterfeits. AFAIK there are few if any American made fuel pumps. That is why I use Bosch pumps. Made in Brazil but in their own factory that applies company manufacturing and quality standards. Bosch P/N 69225 seems to work for all the swaps that I've done. As stated earlier in this post, poor wiring connections or restricted connections will burn out a fuel pump.
It's a Carter Pump I bought through Rock Auto. No ebay junk for this kid. I found a multitude of sins when I tore all the plumbing and wiring apart. Everything will be addressed on this teardown. The pictures don't really show how bad the kinks in the fuel lines really were but the steel braided lines I plan to replace them with will eliminate that. The fuel pump wiring has already been addressed with solder and shrink wrap. The only problem with going with SS braided fuel lines is that it's going to force me into cleaning/dress up the rest of rest of the engine.
[This message has been edited by paulcal (edited 09-01-2014).]
I got all the parts in for my new fuel lines yesterday and got some work done of them today. I still have to cut them to length and add the ends to connect to the fuel tank and finalize the routing but I'm pretty happy with the look so far. I went with -6 A/N fittings and line and adapted the ends. The large connection on the inlet of the fuel rail is the new fuel filter. I was glad when I spotted that while researching connectors. It's cleanable.
Thanks Double M for the pic. How did you route the lines around the exhaust manifolds?
Since this has been an ongoing issue I've decided to start at the fuel tank and just replace every single inch of fuel line and the pump, maybe even the tank sending unit. I have a V6 parts car I can get the sending unit from. I guess I also need to get a reading on the voltage to the fuel pump to see if that may be an issue. As far as I can see, that's the only two issues it can be that's causing it.
Sorry for the late reply.
I didn't go around the manifolds so to speak, just completely avoided them.
The lines just reach back to the sheet metal along the trunk, then they bend over to the drivers side, run under the cruise assembly then over to the frame rail and connect up to the stock lines about where the rear strut is (fuel filter there as well). The rest of the OEM lines are exactly where GM put them. I believe the part numbers for the fittings are in my wiring thread. I will see if I have a picture along the frame rail (don't own the car anymore to take a fresh one).
Edit: BTW I also just used the a stock 2.8l fuel pump - sorry don't recall which brand.
[This message has been edited by Mickey_Moose (edited 09-04-2014).]
The problem with the standard pump is that it runs against pressure. It works too hard. You want a return style pump like the 2.8 setup, with a bypass regulator. The bypass regulator depressurizes the whole system. A pump meant to run at 60psi can be ratched down to 5 psi and stay there. This is my setup and you can scarcely hear the pump with the engine off. Of course there are guys who will disagree with me, but, try a bypass regulator and you'll never go back
The Carter pump I installed is a turbine style pump which recommends that I eliminate the pulse modulator so I removed it and by-passed it with a piece of hose supplied with the pump. I don't have it all back together yet so I'm not sure how that's going to sound. I should know soon though.
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Originally posted by Arns85GT:
The problem with the standard pump is that it runs against pressure. It works too hard. You want a return style pump like the 2.8 setup, with a bypass regulator. The bypass regulator depressurizes the whole system. A pump meant to run at 60psi can be ratched down to 5 psi and stay there. This is my setup and you can scarcely hear the pump with the engine off. Of course there are guys who will disagree with me, but, try a bypass regulator and you'll never go back
