Cause of major bogging on L28ET?

[dpuma8]

Lately when I turn on my car, the idle is good and no smoke coming out of the back. When I start coasting at 20 mph, the gas pedal becomes extremely jerky when you press it in. It only drives right when you try to accelerate harder and then the car feels fine. When I do push it though, the A/F gauge which does not seem to work because 70% of the lights on it will be flashing but it lights up in the Lean area.

 

At idle, the engine sounds like it is fighting to stay alive but it never turns off. The exhaust smell is very strong and there is whitish exhaust coming out of it.

 

Could any of these be the problem?

 

-The gas gauge doesn't work so I am not sure if I am low on gas or not. Would low gas do this?

-My oil pressure ranges between 20 and 45 when driving. When idling, it is about 9.

-When I received the car, it had no oil in it. I added 20/50 oil to it. Too thick of oil? There are no oil leaks out of the engine.

-I have the P90A head and it ticks a lot.

 

I will post a video after work

[sweetleaf]

You probably have a restriction in your fuel supply. Test the pressure under load.

[dpuma8]

Crap! It is getting worse. How do I check for this? Drop the gas tank? There are no unique or new sounds but how do I know if it is time for a rebuild?

[19762802+2]

I would suggest doing some more research you said that the exhaust is burning white which could mean you have a blown headgasket. Do some searching this has all been covered before.

[dpuma8]

I did try to do research but what has me confused is that the car idles fine WITHOUT white smoke. Once I drive and then let it idle again, the engine barely stays alive and I get visible but not too thick white smoke out the back. I would think that if the car started in this bad condition, then it would make more sense to me. So could a blown head gasket still be a cause for okay idle and then rough idle after I drive?

[BLOZ UP]

There could be a number of causes. I would start with checking cylinder compression, then check your fuel pressure at idle and while driving.

[drifterZ_74]

my l28et had the same problem..ended up being lack of fuel pressure..

[Xnke]

I would go straight to the fuel filter, change it. If that fixes your problem, then drop the tank and have it cleaned, then put it back with another new fuel filter.

[JSM]

How is your coolant level? Being white smoke, it may be water. I'm curious to how a lean condition causes white smoke?

[BLOZ UP]

Probably two different issues. At least, now they are...

[dpuma8]

Alright!! I am going cheap and trying to figure out what the problem is so I changed the fuel filter (Which was the original one from 1983) but now the car doesn't start at all now. So I do have some restriction somewhere so I spent $70 on a fuel pressure regulator (This is original as well). Would the next cost effective, logical choice be to change that or go somewhere else? When I turn the ignition on, I do hear the fuel pump turning on.

[Gollum]

How long have you owned and maintained the vehicle? It sounds like you just fixed a problem that was poorly treated in the past with a workaroud. The changes you made have made a difference, so now you just need to figure out why the car won't start. That's easy, you've either got too much fuel, no fuel, no spark, or poor spark timing. I doubt it spark related. So start checking the rest of the fuel system. Check the injectors, then check your lines, then check your pump.

[19762802+2]

Alright!! I am going cheap and trying to figure out what the problem is so I changed the fuel filter (Which was the original one from 1983) but now the car doesn't start at all now. So I do have some restriction somewhere so I spent $70 on a fuel pressure regulator (This is original as well). Would the next cost effective, logical choice be to change that or go somewhere else? When I turn the ignition on, I do hear the fuel pump turning on.

 

Did you put the fuel filter on the right way? Are you sure your getting the right fuel pressure with the new fuel regulator/ fuel filter? did you ever check the compression to see if you possibly had a blown head gasket or a leak somewhere? Just throwing parts at the car isn't going to fix it, You need to do some diagnosis and report back here with your findings so we can help you out.

[dpuma8]

I have owned the car for a few weeks now and I never have really done any car repairing before but I am trying. I don't know a whole lot so that is why I ask these questions just to get a good enough guide into the right direction.

 

I haven't checked the compression yet. The compression tester is in the mail from amazon.com. When I get it, I will do a compression test though. The car felt fine before. It just feels like there isn't really any gas getting to the engine but I guess I will know when I test it.

 

The fuel filter in the car had a tuna can top to it and then it goes into a cone almost with an outlet. With the new fuel filter, I put it in the same way with the tuna can like top on top and reconnected the fuel lines. There were no leaks anywhere. It just won't start now.

 

When I first tried the car, you had to feather the gas pedal a bit to start the car and keep it alive for the first 5 seconds. After that the car ran strong and never turned off until I got these fuel issues.

 

I was thinking of trying to start it a bit and then take off a line to the fuel pressure regulator. I figured if gas came out of a line then my fuel filter was installed correctly and then it might be my injectors, spark plugs, or fuel pressure regulator. Would this be a good idea to do?

[Gollum]

Don't pull the line at the regulator, that's normally a pita. Instead pull a line at the fuel rail input after the filter. I've done that to check pressure before, expect to spill a bit.