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11

Background You asked Why is the effect of a bad fuel pump more noticeable at higher speeds? I assume that by 'higher speeds' you mean engine speeds or RPM's. During high RPM operation an ICE consumes more fuel so the flow rate into the fuel injection system or carburetor increases at higher RPM's. This taxes the fuel system and puts more load on the ...


10

You have a qualitative description of what happens, but let's break it down to a smaller scale. When we talk about "temperature" of something, we are really talking about how fast the molecules are moving around and bouncing off each other. "Temperature" is really "kinetic energy". And it turns out that there are other types of energy besides moving around ...


8

On a car with fuel injection there can be two fuel pumps, one high-pressure and one low-pressure. The low-pressure pump moves the gas from the tank up to the high pressure pump. The high pressure pump then raises the pressure to a level that will be useful to the injectors. The two PIDs reflect those two different systems. PID Description Min ...


8

I will try to answer this as best as possible. There are a few factors that come into play here (Mainly the manufacturer of said engine). Direct injection petrol engines work much like a diesel. You have a low pressure fuel pump that resides in the fuel tank itself, and a super high pressure pump that sits near the fuel rail that delivers fuel to the ...


8

In cylinder pressure is in the 200 psi range. GDI fuel pressure is varied from 500 up to around 3000 psi. This alone is enough to keep fuel blow-back to a minimum. Carefully engineered injector pintle shape also helps. This is no different than port injectors. What is unusual is how the pintle is moved in a GDI injector. In the most successful designs the ...


7

tl dr - To directly answer the question, SeaFoam is a pure petroleum product. If an alternative product is made up the same as Seafoam, then I'd think it would work just fine. If its makeup is not similar, you probably won't see the same results. Below is what you are looking for and a recipe for making your own substitute. I found this answer for a SeaFoam ...


6

Those are metric screw dimensions. M10 means a 10 millimeter outer diameter for the bolt or whatever piece it is; M12 means 12 millimeters. The part after the 'x' is the pitch -- how many threads there are per some unit of length. To figure out which you have, you can measure the existing part with calipers and a thread gauge. You might also try calling ...


6

The injector has a plunger/pintle which is controlled by an electromagnet. The humming you heard is from that. The plunger/pintle has a spring which pushes back against the electromagnet so when the power is shut off, the plunger will close and stop the flow of fuel. This causes the hum. Here is an example of how an injector is built: When the power is ...


6

Direct Injection has a lot of advantages over the MPFI or port injection and its the way of the future. It improves mileage through a stratified charge engine process(basically staying as close to the stochiometric ratio as possible this achieving better burn. Lower emissions. Prevents engine knocking/detonation. Better control of the engine since before ...


6

It's a demand vs supply deal The fuel pumps found in most OEM fuel delivery setups today are driven by an electric motor that is running at a fixed speed. This effectively fixes the flow rate provided by the fuel pump. The majority of fuel-delivery systems found in fuel-injected vehicles are return-style. What this means is that the fuel injectors will ...


6

Funny you should ask this Max :) First lets make sure of our definition. Running an engine lean means changing the air / fuel ratio to have more air than is ideal (14.7:1 air to fuel). In my reading there are two effects. First, the fuel is an atomized liquid which has a cooling effect on the combustion chamber. So less fuel, less cooling effect. Second, ...


5

That pipe probably goes to the tank too, it is just there to let air out of the tank while adding fuel down the main pipe. I believe that your additive will be in the fuel.


5

If you have ever seen an oxy-acetylene torch being used, you will have noticed that before the oxygen is turned on, the torch has a bright yellow flame. This is the fuel burning in a less than ideal amount of oxygen. The flame is relatively cool and it produces a lot of soot. When the oxygen is turned on, tthe flame turns blue and becomes hot enough to ...


4

The quick answer is - Yes, you will need a tune after installing larger injectors in your stroked 454. I was considering a big block swap into my RV so I've done a bit of research about tuning solutions. I was primarily focused on swapping in the L21, so I can't speak 100% to the differences between the Mark IV and Gen VI motors. This is what I do ...


4

If "injector cleaning" products helped but only lasted for one tank, I would try spraying Seafoam directly in at the throttle plate rather than putting an additive in your fuel. This should be a lot more effective at cleaning the injectors. If that doesn't help, my best guess would be that the vibration is from unequal power from one or more of the ...


4

I've had this problem with my Honda accord 96 for an entire year and just figured out what was causing the vibration in idle mode. Changed mounts, cleaned air idle control valve and throttle body . Took it to a friend who in no time told me it was a BAD COIL not producing enough power. So check out your COILS


4

Yes, it will probably be necessary to fix the problem in order to pass emissions requirements. The secondary air injection pump on the Beetle is apparently used to accelerate the transition from cold start to hot catalytic converter operation. Without this system, it will take longer for the catalytic converter to reach operating temperature. The ...


4

Don't be hasty to replace the whole CIS! Based on the Bosch Fuel Injection & Engine Management book, here are a few things to investigate as possible causes for hot-start issues (inability to start when the engine is warm): Cold-start valve leaking or operating continuously The cold-start injector is designed to enrich the air-fuel mixture while the ...


4

Thanks for the great detail. Considering this is a bit of an odd issue, I'll try thinking outside the box a little. But first I would use a multimeter to test the coolant temp sensor, then o2 sensors. Perhaps even a quick check of the upper radiator hose to make sure the thermostat isn't stuck open. I say to check these first because it sounds like ...


4

You can do this through the OBD-II protocol (SAE J1979).: +------+-----+-------------------+ | Mode | PID | Description | +------+-----+-------------------+ | 01 | 5E | Engine fuel rate | ( liters/hour ) +------+-----+-------------------+ | 01 | 43 | Engine RPM | +------+-----+-------------------+ You can use the RPM to figure out how ...


4

"Why can't people just upgrade fuel pumps and increase fuel line (pipe?) pressures to force fuel to flow in to the engine when the intake valves are open instead?" This is the job of the fuel injector/ECU. It is timed specifically so the proper amount of fuel is injected at the correct time. The ECU is tuned for a specific fuel pressure and can typically ...


4

The gas gauge is just an indicator and each vehicle is going to be different. I know the older Datsun Z cars had two gas gauges, one was the main one which showed the volume of gas down to 1/4 tank, while the secondary one showed from 1/4 down to empty. The secondary gas gauge was very accurate to give the driver a true indication of how much fuel was in the ...


3

Here is an image with the different types of injectors. It looks as though the brown top injectors you are talking about are 36 lb injectors, meaning they can flow 36 lbs of fuel per hour at the stock fuel pressure. I don't know what the fuel pressure these were rated at for 36#'s, but if you have lower or higher fuel pressure in your vehicle, this will ...


3

Here are the instructions I found from this document. It looks as though you have to program the pump and injectors into the PCU using some type interfacing tool. I would bet this is probably only available through the dealer, though I could be wrong. Check with a local shop, but would bet this is not something you can do at home. The document has several ...


3

Sounds like the Idle Air Control Valve and the Intake Manifold must be removed and cleaned. The vibration is worse when in gear than in neutral In gear there is a much greater load on the engine. Power is being transfered to the transmission and then to the wheels. This is going to cause the idle to drop a bit and this is where you'd feel the most ...


3

One option you may want to consider is switching to a MegaSquirt fuel injection computer. It would be the pain of a fuel injection computer replacement, but they seem to be rather adjustable and configurable, if you are willing to go through the effort. We have had a couple of presentations at a local computer club from a guy who converted his 60s era ...


3

I'm sure there are a plethora of custom programmers for the suburban platform. However if you're making such extensive modifications, you can probably look at some standalone solutions, like an Accel DFI or Haltech setup. Tuners typically dial in a baseline map and strap your vehicle to a dyno where they adjust fuel/timing curves according to wideband O2 ...


3

Your post raises several possible issues that you could eliminate to start with. Firstly if it is still on an incline I suggest you push or tow it to flat ground. It will help rule out fuel starvation and make it easier and safer to work on. Second i would drain the fuel tank and put fresh fuel in it. From there you can try starting it a few times. ...


3

In multi port fuel injection the injectors are located near the Intake valve. In central port fuel injection there is a single injector with multiple valves that route to their respective cylinders. Think the 90's Chevy Blazer with the 4.3l Vortec. There is also throttle body fuel injection in which a single injector is located at the throttle plate. As ...


3

An engine only needs a few things to run: fuel, air, compression, and spark. Considering the engine runs fine once started, I would guess the engine has enough air and spark. A lack of air would cause rough or erratic idle, and lack of spark would stall the engine, or at least cause it to stumble, shake, and generally sound unhealthy. It would also be ...



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