Bingle

Forgive the long winded story but just want to give all info. I've been running the DCOE's (dual side drafts) on the truck for about 8 years with almost no trouble till now. I had to go to a aftermarket elec (low psi) fuel pump due to intake clearance problems with the mech pump. About a month ago (the toyota is not my dd so it tends to get put in time out when it acts up) the fuel pump died. Went to the local O'Rileys (gag) and they didn't have the same pump but they had a Mr gasket one that was a 2-3.5psi unit. This:
http://www.spiderautomotive.com/mrgasket42s.html

Seemed to work fine but now would starve for fuel. Needle valves were sticking. Cleaned them up and seemed to work fine for a while (occaisonal stumble/jerk but not often). Put most of a bottle of sea foam in the tank and changed out the fuel filter when I did the new pump. Was in the process of moving and made it through that okay but decided to get progressively worse. Luckily it was only about 3 mi that we moved.

Got to where it was trying to die a block or two down the street, I figured the valves were sticking again so I ordered rebuild kits for the carbs and last night installed the new needle valves and seats, carb fuel filter, and top gasket. Didn't want to remove the carbs and go through them as they looked really clean and didn't want to bother (PITA). Also adjusted the floats. Figured I had it all figured out now and fired it up. Idled in the driveway just fine, reved just fine. Let it warm up and went far a test spin just to be sure.
Made it less than a block.

It SEEMS like it's starving out and dying. It sputters and quits, I let it sit w/the fuel pump running but not trying to crank for about 1 min and it'll fire up. If I try before that it won't kick. Limped it back to house sputtering and trying to die. Pushing in clutch and pumping the gas a little seems to help keep it running, just barely.
Fuel pressure gauge sits at about 3.25 while at idle and dips down to about 2.75 when I throttle it up. Don't know what it's doing when I give it gas under load cuz gauge is under the hood.

I have no fuel pressure regulator and think that the old pump was prolly pushing a little harder than webber spec but no more than about 5.5 (I didn't even have a gauge cuz it was working fine).
So, my questions/ideas:
1: The fuel pump isn't moving enough fuel when under load and I'm draining the bowl?
2: The fuel pickup in the tank is getting clogged (sea foam broke a bunch of crud loose?)? Crud settles when I let it sit for a while but when I start driving it stirs up and clogs the intake filter?(I have never dropped the tank and looked at it so I have no idea what shape it's in) I have a visable fuel filter in line and it looks good.
3: One or more of the jets in the carb is cloged? No sediment in bowl or anything that leads me to believe this is the case but I could be wrong.
4: ???????

Any insight would be aprecated. Tired of chasing my tail on this one. Pardon my spelling.

Bingle

Feeling like I might have to just spring for a weber elec pump and press regulator but I just got our house and don't want to spend the money if I don't have to.

84YotaBuck

Had a similar problem years ago, it turned out the old fuel line would collapse under accelleration. Would idle fine, could putt around fine, but when you had to go up a hill, or give it some gas to get going the fuel line would collapse and starve out the engine.

Bingle

thanks for reply, that would be an easy fix! let's hope that's it.
anybody else have anything?

suncomb1

You do not say what size DCOE carbs you are running but all DCOE carbs should only run with 1-1.5 PSI fuel pressure at the carbs otherwise they flood. You need to run a return type fuel pressure regulator and the the return line must be large enough so the regulator can control the pressure at the carbs properly. It also sounds that your idle jets may be too small; go 1-2 sizes up to see if that eliminates the bog. Also set your ignition timing at 30-32 degrees total advance with it all in at about 2000 RPM.

Bingle

Thanks for the info, they're 45 DCOE 152's. I think the idle jet is fine, was running great for years before everything went to crap on me recently.

I've heard conflicting stories on what psi to run webber carbs at. Most I've seen lately say that they run best in the 3.5-4 psi range and the max 2 psi number was an older recomendation. I don't know for sure and will keep an eye out for the flooding and reg to where they seem to work best.

Did some work on it last night, Mr. Gasket fuel pump was bad. Barely moving any fuel. I had about 3 hours total run time on that pump. What a piece of garbage!!!! Stay away from them!!!! Got a new carter low psi pump and re-plumbed all soft lines from the tank to the carbs and blew out the hard lines. Was too late when I got done to take it for a spin but I'm hopefull. Looks good and seemed to be "working". Will update when I know.

suncomb1

I run the same carbs-Max fuel pressure at carbs 1-1.5 PSI. My engine is a full race unit pulling 285HP so maybe your Idle jets are fine but I needed to go up in size. I run 40MM chokes also.

Bingle

Thanks again suncomb. Good to find someone else on this forum running dcoe's. Not many of us out there, at least not that I've seen. I love them but finding info and resources for them can be tricky. Will try bringing it down to the 1-1.5 range and see what happens. I know I've been running higher psi than that for years but maybee would help some with my mpg. Never had problems with flooding but may have been too full and sucking extra.

Quick question, Looking for float level adjusts in the weber manual I have it breaks them down into different models. Mine have a #152 at the end. Didn't see any 100#'s so figured it was a 15 series and used those float levels. Is my assumption correct or does my manual just not have the info for my carb?

suncomb1

I set my DCOE float level at 12MM. I also run spring loaded needle / seat units. I run an Air / Fuel ratio of about 13:1

Bingle

Weber manual called for 7.5mm for 15 series. I will prolly drop it to 11-12mm. I have the plastic floats if that makes any differance (what it came with).

Bingle

what press regulator are you using? I want to run a return type as you said, prolly help the life of the fuel pump. Kinda been winging this stuff on my own so finding someone who has one set up "right" makes me wanna pick your brain. Thanks for all the help.

suncomb1

Factory spec for float level on a DCOE 45-152 is 12MM. I run a Mallory 110 series electric fuel pump and a Mallory #4309 3 port return type regulator. I run a AN size 8 hose from the fuel pump outlet to my fuel block and a size AN 6 hose from the fuel block to each carb. I run a size AN 10 from the return port on the pressure regulator back to the fuel tank. Mallory has tech info on their WEB site regarding fuel return line sizing. With a return type pressure regulator you achieve better fuel pressure regulation; same as a pressure regulator system on fuel injection systems.

suncomb1

Photo Of DCOE carb setup.

Bingle

Specs I'm seeing shows that reg only going down to 3psi, are the specs wrong or is you pump adjusted down too to get you to that 1-1.5 psi?
Sorry to keep bothering you on this, just really want to get this right without spending a lot of extra. Your truck is awesome by the way. What kind of LC engine do you have? I got their mech dizzy when I went to the dcoe's and lust after their engines on a regular basis.

suncomb1

The specs are based on the fuel pressure available at the inlet of the pressure regulator. My electric fuel pump outlet pressure is adustable and can be lowered thus lowering the available pressure to the inlet of the pressure regulator. The 1-1.5 PSI reading is at the carb inlet so if you adjust the regulator to achieve that reading you have compensated for the pressure drops in lines to the carbs, fuel block, etc.

Bingle

Update. Problem solved!! Installed a weber/redline fpr and adjusted down to 1.5 psi and she runs great now!
I think that the original elec fuel pump I had was getting me close to the right press (I didn't have a gague until I started having problems) and the new pumps (mr gasget before it crapped out and new carter that's working great) were both pushing 3-3.5 psi.

suncomb1, thank you again for all your help. I went with the weber fpr instead of the Mallory because I wanted to be sure I could get down to 1.5 psi with my system. Didn't want to buy the part, install, still be too high, and explain to the wife why I need to spend more money.

Perhaps someday mine will be as well done and pretty as yours, but it's working great for now.

suncomb1

Understand with the wife. My LC Engineering motor is a custom specified Stage 5 Pro Stroker with 20R head. The cam, pistons, valves and numerous other things were specified by me. The engine runs strong and is set up to run Nitrous (I hit the "Juice" sometimes when the wife is not with me Ha! Ha!).

Bingle

I was wondering what the rail on the pass side of the valve cover was. Your nos right? If not, what is it?

When I get due for a rebuild (probably not for another 100k mi, damn you toyota relibility) I plan on getting a Lc stage 3 stroker. Stage 5 would be cool, but convincing the wife the $$$ for the stage 3 is needed will be hard enough and mine is more of a trail rig/ firewood getter.

Do you feel that the Lc engines are worth the premium price they ask? Just want the oppinion of someone who has one.

I wish I had known about Yotatech when I was building my truck. Lots of things I would change/do different.

suncomb1

The rail on the valve cover is a tube type tank vacuum accumulator. When you run a radical cam you need one so the power brakes work properly. The nitrous system is underneath the intake manifold. There are 4 jet systems (one for each cylinder) installed and I run a separate high pressure electric fuel pump and fuel pressure regulator for the nitrous system. The controls for the nitrous system can be configured to have the nitrous come on all at once or staged. There is an Air-Fuel Ratio Controller installed in the control system.

As far as LC Engineering engines go I would not purchase an engine from anyone else. You only get what you pay for, and yes you could build a small block Chevy for what an LC Engineering engine costs but I do not have any problems with the motor, it performs as I expected, their Tech Support is outstanding and they stand behind their work.