chrisbergusmc

So I am having knocking issues with my FD, I'm assuming that it's due to it running lean, also I'm going to have the engine rebuilt. this is just how I bought the car so I'm just trying to get it back to the best condition I can. My main question is about the lean fuel mixture. I dont plan on adding many if any more power add ons besides what is already there and sending the engine to Pettit to get rebuilt and street ported with 3mm apex seals. Will I be OK getting the injectors cleaned/replaced at the stock 550cc and 850cc level or do I NEED to upgrade to something larger?

Current list of mods is as follows:

Engine -- Pettit intake, 3" exhaust, Pettit pulley kit, Rebuilt/ ported turbos, Polished intake and turbo housings, battery relocation kit, M2 Large intercooler, fluidyne radiator, CWR twin oil cooler kit, Greddy elbow, Greddy BOV type-S, Down pipe, Mid pipe, ACT clutch kit, ACT lightweight flywheel

Engine Management -- Pettiit ECU

Suspension/Brakes/Wheels -- AP racing big brake kit, Steel braided brake lines, Eibach springs, GAB 8-way adj. shocks, R1 strut tower brace, Volk SE37K 18" bronze rims

Interior/Exterior/Electronics -- Pettit column mount boost gauge, SPA oil pressure/temp gauge, SPA fuel pressure/ water temp gauge, '99 front lip spoiler

Thanks in advance for the help here.

Jay7 Nyc

iTrader: (3)

I would get bigger injectors... You can either tell pettit or contact Steve from gothamracing.com for the setup..

MR_Rick

iTrader: (7)

Bigger injectors will not work with the Pettit ECU. I was thinking about this too, because I'm pretty much going the same route. I'm sending my injectors out to get clean by RC Engineering, but I was thinking of either getting a fuel pump upgrade, fuel pressure regulator or a Apexi S-AFC to fine tune. But I'm not sure which one of this option will be better witha Pettit ECU.

chrisbergusmc

I was actually just looking up getting my stock injectors cleaned by Marren Motorsports and getting the nippondenso supra fuel pump, replacing the fuel filter (just in case) and getting the Apexi avc-r to make sure my boost stays down for now.

rynberg

I doubt you are hearing knocking, if you were, the engine would most likely already be gone.

You cannot run larger injectors with a Pettit or piggyback style ecu. You need a real standalone computer like a PFC to do this.

Whether or not you NEED higher-flowing injectors really depends on how much boost you want to run. If you want to run over 13 psi, you really start hitting the limits of the stock injectors. Under that and you're fine. You don't need a higher-flowing fuel pump unless you upgrade the injectors.

Also, the S-AFC is pretty useless for the FD, your money is better spent on the proper standalone.

chrisbergusmc

here's the kicker for you rynberg, I haven't even seen the car yet. I bought it back in november knowing it needed it an engine rebuild, or so the seller said. I had it shipped to my parents house and it has been there ever since. I only hear from my younger brother that it is knocking, it has only been run about 3 times since it has been there for about 5 minutes per time it has moved about 10 yards (I don't trust them driving it around) and with the amount of add ons and with what I read everywhere else it made sense that it may need more fuel. Also I had them check the color of the exhaust gas, it had a whitish hue to it making me think that it also has a coolant leak, most likely in the engine seeing as how the turbos were already rebuilt.

Basically all my troubleshooting is being done by word of mouth right now. Not the best way by far, but whatever is wrong I want to at least have a plan to fix it and a cost estimate before I go spending all this money. I'm not trying to be a smart *** or anything, just trying to get you to see where I'm coming from.

Thanks again.

Trout2

iTrader: (5)

RP/rx7.com recommends new injectors when rebuilding and I've seen a couple of local people have problems with high milage injectors after cleaning. I bought mine from the Rx7 Store.

I'd sell the Petit ECU and get a PFC so you can run larger injectors and feel safe running more boost. With a ported RP motor, all the bolt-ons, 4x850cc injectors, and 11psi/327rwhp, I was seeing low 80%'s for duty cycle. I've since changed the secondaries to 1300cc and see low 70%'s with 13-14psi.

Jack

chrisbergusmc

Mine aren't that high mileage though, just under 42,000. I'm not really looking to make gobs of power right now as I just got this car, I'd like to get used to it's handling characteristics first. If I NEED to replace them I will, the main thing here is , are the stock injectors going to be able to support this setup safely at stock boost patterns.

I'll probably end up getting the larger injectors down the road but for now my main focus is getting the engine rebuilt and making sure that it will be reliable until I have enough money to move to other projects like an ECU and fuel system.

rynberg

Yes, the stock fuel system should safely support that setup at boost levels under 13 psi.