surging when cold

[Cold Chuck]

Hello,

 

I have parked my '04 Dodge Ram with Cummins to drive this 1987 Subaru Wagon with auto. Engine is EA82 with carb.

 

When the engine is cold (after sitting overnight), I start engine and drove. It surges when the throttle is floored and it looses power and regain power again. I put in some seafoam in the tank and some in the carb. When the engine is warmed up, it runs okay. Sometimes but not always, it diesels for 5-10 sec. when the key is shut off. No backfire and I did not hear pinging.

 

A bit of background, this car sat in my garage for months but it ran well before. I refilled the tank from 1/2 full to full mark and dumped seafoam in it.

 

Do u think the carb needs cleaning or what?

 

One more question? the plastic tube for window washer broke where the tube enters the firewall. Does the dash needs to come apart to replace the clear tube to the washer spray nozzle? How hard that job is?

 

Thanks!

[mountaingoatgruff]

have you tried changing the fuel filter?

 

i'd do a full tune-up if this is to be your daily driver from now on.

[Cold Chuck]

Okay..

 

I am a diesel mechanic for large trucks not this little cars.

 

I checked timing with dist advance plugged. Engine running at just shy of 1000 RPM (automatic 4x4 tranny). Timing was set at 10 BTC. I adjusted to 8 degrees. I replaced the cap /rotor and the spark plugs (set at 0.040" gap). My home base altitude is 6,500 ft and my workplace is at 10,000 ft. Is there any thing special I need to do? This car used come from sea level.

 

I bought new fuel filter and I can't find the old one anywhere in engine compartment and I can't fit under the car being that its low to the ground. So Please tell me the location of the filter?

 

And one other unanswered question about windshield washer tube. I would (no scratch that..) I must have that clear tube fixed so I do not know what the repair procedure for this. It just broke at the firewall grommet and I can't get it the other half out to replace the tubing? Does the entire dashboard needs to come out to replace it?

 

So thanks for the help! :-\

[screwbaru2]

Cold Chuck, I would check the choke related items. Also check for vac leaks. A small leak would be more noticable when the engine is cold and supposed to be choked. If it surges at hot idle at all, I would start looking for vac leaks first.

Spray carb cleaner on the vac hoses then around the intake when you spray the leak the rpms will increase for a moment then idle down again.

I'm not familar with the setup you have but, carbs I know and they have different ways to do the same thing. First the choke plate must close when the motor is cold and open a certain amount after the motor starts.

The idle is usually increased at cold start and then is decreased when the motor is hot. Check those items and adjust anything that isn't right.

[GeneralDisorder]

You might check at the dealer and see if they can still get you a "high altitude" kit for it. They made them when these were sold new. It will probably just reroute some hoses - they may even be able to tell you how to accomplish the same thing with off-the-shelf components if you ask them to look it up in the factory service literature.

 

GD

[Cold Chuck]

There is very slight surging when engine is warmed up - not as bad as when cold. After driving and parking, engine would be idling at 1100-1200 RPM and dieseling when shut off for few seconds.

 

I haven't changed the fuel filter because I can't find the old one.

 

Here what I have done:

1) changed all spark plugs

2) changed cap and rotor

3) checked spark plugs wires resistance

4) put seafoam into carb about 1/4 of bottle (to the point where it stumbles) and dumped rest in tank

5) checked timing - was set at 10 and adjusted to 8.

6) inspected for cracked vacuum lines

 

That's about it. I will try again with carb cleaner spray.

[Cold Chuck]

The surging feels like to me that I'm running out of fuel and then when RPM drops (with throttle held down) then all of sudden engine surges ahead with more power up to around 4000 RPM and then drops back down. It does it worse when the throttle is held down to the floor on a up grade. I managed to make this go away when I put the throttle no more than 3/4 of travel but boy its sure slow not like my HO Cummins engine with stage 1 injectors. I knew that its a gasser not diesel and with diesel prices (4.75 a gal) is killing me.

[Cold Chuck]

"You might check at the dealer and see if they can still get you a "high altitude" kit for it. They made them when these were sold new. It will probably just reroute some hoses - they may even be able to tell you how to accomplish the same thing with off-the-shelf components if you ask them to look it up in the factory service literature.

 

GD"

 

I googled for the kit. All I could find was for aircraft - specifically ultralight aircraft. I did not know they use this engine to fly the planes!! Does anyone has info on this kit? Will that help my surging condition? I checked Alldata and there is nothing in there about this kit. Must be dealer black bag item?

[GeneralDisorder]

All of the carburated models had something availible for altitude compensation. You will want to ask a dealer directly. As for the surging - it's possible that it could be related but I couldn't tell you for sure. I live at sea level and all my experience with the Hitachi carbs is at lower altitudes.

 

GD

[GeneralDisorder]

The fuel filter is under the car next to the pump. They are both on a shelf forward of the fuel tank.

 

Sounds like you should change it on general principle. I haven't had the surging like you sugest, but I have run out of fuel at WOT with a partially clogged filter.

 

Do the cheap stuff like that first before worrying about the altitude compensation.

 

GD

[Cold Chuck]

That did it. Changing the fuel filter cured the surging. I wish someone could have warned me about messy job - LOL. I had to jack up so I could fit under the car.

 

Now only last question remains - how do I replace the plastic tube for windshield spray nozzle behind the firewall? As I mentioned before the tube broke inside the firewall - inside the grommet. This needs to be fixed as clean windshield is a must here!

 

I will contact the dealer and find out about high altitude kit.

 

While I was driving, I keep hearing little noise coming only from right rear wheel. it sounds something rattling and goes away past 30 mph and at stop. I dunno what that was.

 

By the way I sprayed entire carb and intake areas and all the vacuum lines and stuff with carb cleaner and I could not get the engine to rev up. Some of the vacuum hoses are stiff but not cracked. So I guess I will have to find the time to replace them all. What size are the hoses?