开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. SubaruVanagon
  2. Topics

EG33 Hard Start

 

I converted my 86 Westy to EG33/Subarugears back in 2018 and everything has been peachy until recently. I now need to crank the van for quite some time before it starts. Once it does, it fires right off and idles like there was no problem. I can immediately turn it off and restart with no problem so I don’t think it’s a coolant temperature thing. If it sits overnight, the problem pops up again. It doesn’t seem like it’s flooded as holding the throttle wide open makes no difference. I ?can also let the fuel pump cycle a few times and, no difference. It seems more like an ignition problem than a fuel one though it runs perfectly once it has started. I have read where someone else with a EG33/Impreza swap had the same problem and everyone suggested the coolant sensor but it made no difference to him. The coolant doesn’t warm up without the engine running… Mine sounds like exactly the same problem. Has anyone experienced this?
 

开云体育

I have had the same issue on my 05 Chevy Suburban. I know apples and oranges but hear me out.?
My fuel pump was bad. It had a small leak in the internal diaphragm that would slowly leak the fuel pressure were it was difficult to start at first but once going it ran flawlessly unless it sat for about 6 hours, then it would act up again. Once I replaced the pump, no more problems starting at first key turn with almost instantaneous starting.?
I hope this helps.?
John

On Dec 23, 2023, at 7:25?PM, todd s via groups.io <tsorel1600@...> wrote:

?I converted my 86 Westy to EG33/Subarugears back in 2018 and everything has been peachy until recently. I now need to crank the van for quite some time before it starts. Once it does, it fires right off and idles like there was no problem. I can immediately turn it off and restart with no problem so I don’t think it’s a coolant temperature thing. If it sits overnight, the problem pops up again. It doesn’t seem like it’s flooded as holding the throttle wide open makes no difference. I ?can also let the fuel pump cycle a few times and, no difference. It seems more like an ignition problem than a fuel one though it runs perfectly once it has started. I have read where someone else with a EG33/Impreza swap had the same problem and everyone suggested the coolant sensor but it made no difference to him. The coolant doesn’t warm up without the engine running… Mine sounds like exactly the same problem. Has anyone experienced this?

 

Fuel pressure regulator?
 

Hi Todd, That's my vote too. Fuel pressure regulator. It is letting the fuel pressure bleed off in the manifold to injectors. Paul?


On Sun, Dec 24, 2023 at 2:25?PM Wayne Sitarz <wesitarz@...> wrote:
Fuel pressure regulator?

 

Try a little shot of "starting fluid".? If it fires, you have verified that the? ignition is OK.
 

I will try these out. Thanks.
 

It’s the fuel pressure regulator. I put a gauge on the pressure side out of the pump and saw 65psi. I then put the gauge on the return line off the fuel rail and saw 65psi. The regulator was just letting the fuel right through. I left the gauge on (dead headed) and cranked the engine, it fired right up. I guess the FPR is acting too slow to close. I just need to determine now if it uses manifold vacuum to close or vacuum to open before I replace it.
 

I do not know if 65 PSI is appropriate.? But I do know that if you have pressure on the return side of the regulator then you have a restriction or I would say blockage on the return side.? There should be ambient pressure at all times on the return side.?
?
I would perform the measurements again and confirm the findings.
?

Harold Mead
?
?

From: "todd s via groups.io" <tsorel1600@...>
Sent: Tuesday, December 26, 2023 5:20 PM
To: [email protected]
Subject: Re: [SubaruVanagon] EG33 Hard Start
?
It’s the fuel pressure regulator. I put a gauge on the pressure side out of the pump and saw 65psi. I then put the gauge on the return line off the fuel rail and saw 65psi. The regulator was just letting the fuel right through. I left the gauge on (dead headed) and cranked the engine, it fired right up. I guess the FPR is acting too slow to close. I just need to determine now if it uses manifold vacuum to close or vacuum to open before I replace it.





?
 

Don’t think you understood how I applied the gauge. I did not tee it in, I essentially plugged the outlet line with the gauge. 65 psi is the capability of the stick Vanagon pump when it is fully “dead headed”. The fuel pressure regulator is supposed to drop that down to 36 psi to supply the engine, with the rest returning to the tank.
 


I believe you don't understand the operation of the pressure regulator, specially on these engines (and typical return style fuel injection FPRs)? usually the style used is call a by-pass regulator

On a typical fuel injected car (which has a return) you check the fuel pressure on the feed side with a tee fitting (in line with the feed) to get an accurate reading.? usually you do not dead head the system, be it feed or the return, which can cause damage to the fuel pump, pop a fuel line and thou not common lock an injector in the open position

So on the feed side, it should be @40 psi =/- 5 psi (don't know the specs off hand) with the fuel pressure gauge inline with the feed line (allow the fuel to go to the engine) the return should be left open to return to the tank (if plugged it will build up pressure to what the fuel pump can pump too, since the excess pressure can't be bleed off)

Now a return-less system, thou one would think its deadhead, and typically it is, but the excess pressure is usually bleed off inside the tank ('06+ EJ253s), or the pump is just PWM controlled with a feed back control from the fuel rail pressure sensor



 

I understand how the system works

1 - 11 of 11