5x18 injectors too small for 13mm pump?

stevemiller67

stevemiller67

New member
So I ran my truck on the dyno last Saturday and could only get 630hp at best out of it which is lower than anticipated. I noticed on the few test runs on the street the truck smokes excessively as it did on the dyno as well. The truck doesn't seem to come alive in the higher rpm like I thought it should either, but I believe this overfueling issue is why. The engine mods are the following, DFI 5x18 SAC injectors, 13mm pump( professionally built at an injection service shop) 0.93 lines, airdog 200(holds 55-60psi) , s480, 188/200 cam, ported/polished head with runner intake, with supporting mods. * The pump was set 25* timing and 600cc's of fuel for a base line and the truck smokes excessive with the turbo fully lit @45psi of boost. *First tried going to 30* timing but gained no power and smoke levels were the same, then pulled the fuel plate all the way back and the smoke levels dropped some but still would not clean up. So my question is, are the injectors too small and hanging open to long into the exhaust stroke causing the smoke issue? I'm going to pull the injectors and test them but would like some opinions on the matter. I was planing on going bigger for injectors but am putting this project on the back burner for awhile so I wanted to run it where it was at and see what it did.
 
stevemiller67 said:
So I ran my truck on the dyno last Saturday and could only get 630hp at best out of it which is lower than anticipated. I noticed on the few test runs on the street the truck smokes excessively as it did on the dyno as well. The truck doesn't seem to come alive in the higher rpm like I thought it should either, but I believe this overfueling issue is why. The engine mods are the following, DFI 5x18 SAC injectors, 13mm pump( professionally built at an injection service shop) 0.93 lines, airdog 200(holds 55-60psi) , s480, 188/200 cam, ported/polished head with runner intake, with supporting mods. * The pump was set 25* timing and 600cc's of fuel for a base line and the truck smokes excessive with the turbo fully lit @45psi of boost. *First tried going to 30* timing but gained no power and smoke levels were the same, then pulled the fuel plate all the way back and the smoke levels dropped some but still would not clean up. So my question is, are the injectors too small and hanging open to long into the exhaust stroke causing the smoke issue? I'm going to pull the injectors and test them but would like some opinions on the matter. I was planing on going bigger for injectors but am putting this project on the back burner for awhile so I wanted to run it where it was at and see what it did.
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Seems like it could be a boost leak. That boost number is very low for what id expect out of those compounds. What is your drive pressure and egt?
 
I've got a 13mm pump with 6x.013s that sounds like it's doing the same thing. No boost leaks, good fuel pressure, timing checked, etc. The turbo comes up as expected and makes boost but the truck just pukes smoke and doesn't make the power it should. I've isolated my problem to the pump, I'd start looking there.
 
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I've ran mine before with a 13mm pump, and 5×18 injectors, full cut delivery valvaes. Ran good and was very clean with my pump set at 550cc's. This was on compounds though.
 
zachu812 said:
I've got a 13mm pump with 6x.013s that sounds like it's doing the same thing. No boost leaks, good fuel pressure, timing checked, etc. The turbo comes up as expected and makes boost but the truck just pukes smoke and doesn't make the power it should. I've isolated my problem to the pump, I'd start looking there.
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It's been about 10yrs ago, but I bought a 13mm pump from a smaller shop. I fought that pump for about a year, would smoke like hell all thru the rpm range but never made good power. I tried everything possible, it ended up hanging the rack on me and running away. I sent that pump in as a core to another shop and he gave me a huge list what they did wrong and why it wouldn't run.
 
jasonc said:
It's been about 10yrs ago, but I bought a 13mm pump from a smaller shop. I fought that pump for about a year, would smoke like hell all thru the rpm range but never made good power. I tried everything possible, it ended up hanging the rack on me and running away. I sent that pump in as a core to another shop and he gave me a huge list what they did wrong and why it wouldn't run.
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Yep. Get a good pump, then build a truck around it.
 
Vincejax said:
Seems like it could be a boost leak. That boost number is very low for what id expect out of those compounds. What is your drive pressure and egt?
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It's a single s480, and I thought the boost numbers were decent considering the head is ported and has a runner intake.
 
I'd have a hard time believing it's the pump, I worked at the shop that built the pump at the time and helped assemble it and calibrate it as well. It's 100% Bosch parts, being they are a Bosch dealer. The guy that built the pump is a genius when it comes to injection pumps but 90% of the pumps he did were stock or close to stock applications. So with that in mind I'm not ruling the pump 100% out either.
 
To much fuel and it's putting the fire out. When I ran my 13mm, 5x18 and S480 I was only at about 500cc. But my timing was 40* .
 
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DISTURBED said:
To much fuel and it's putting the fire out. When I ran my 13mm, 5x18 and S480 I was only at about 500cc. But my timing was 40* .
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What's weird is I pulled the fuel plate all the way back from where it was at(bench tested at 600cc) and it still poured smoke. So with the fuel plate all the way back I would guess it was at most 500cc, but probably less.
 
stevemiller67 said:
What's weird is I pulled the fuel plate all the way back from where it was at(bench tested at 600cc) and it still poured smoke. So with the fuel plate all the way back I would guess it was at most 500cc, but probably less.
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13mm with no rack travel + 325cc’s +/- a few cc’s, depending on what plate your running full back will add a decent amount. I’d lay my $ on your under the turbo.
 
Strap in to a dyno and have someone spray some nitrous into the intake plumbing. Just enough to get the turbo to come up and then see what happens when you stop spraying. Wheaties are the breakfast of champions, Trix are for kids, and compound turbos are for problems like this.
 
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