EGR/misfire issue

Good morning.

Does the engine stall at idle? that will tell if the EGR is the issue.

As far as the shutter, do you mean misfire like and engine miss?

Roy

With the EGR connected or disconnected the engine runs the same and does not stall at idle or at another time.

I got a misfire code along with the EGR problem on the computer readout at AutoZone so that may be the real problem here but not sure what to check next.

Can you explain the shutter????

It is a consistent shudder and it is really bad under acceleration. When coasting or at idle it is not near as bad but still there. When I hit the throttle while in park it does it as well. It almost feels like someone is shaking the car. The engine appears to shake while I move the throttle under the hood.

Okay.

It sounds like all the cylinders are not working.

How old are the ignition components? plugs etc?

also, a compression test would be a good start to be sure the engine is good.

Roy

Hello TMINER,

If you decide to conduct the compression test yourself here is a link to an article from our site with written step by step instructions, pictures and video to guide you:
https://www.2carpros.com/articles/how-to-test-engine-compression

If you have any questions or need further advice please reply to your post and one of experts will be happy to help you.

Thank you for visting 2CarPros and have great rest of your day!

Renee
Admin

Roy the plugs and wires are old. They were on the engine that was put in my truck to replace the engine that was in my truck before it got melted by a family member towing a loaded trailer. The cap and rotor I believe are new. I was going to possibly get new plugs today as the wires are all okay I believe for now. The plugs are not much also.

That is a good start. Start with basics with the ignition parts.

keep me updated.

Roy

New plugs helped some, wires did not. I now went back to O'reillys and have 13 unique codes. They are:
P0405 EGR Sensor A Circuit Low
P0302 cylinder 2 misfire
P0300 random multiple misfires
B1054
B1061
B1071
B1025
B1026
B1015
B1018
B1019
B1021
B1024

I am still leaning towards EGR because I'm getting exhaust fume smell. Maybe I should soak the pintle area in carb cleaner overnight? I know not to dunk the thing. The pintle error I had isn't there now though. The service engine soon light still flashes but usually only when I accelerate and I get the shake.

ok did you do a compression test while the plugs were out as I suggested??

If they are ok, the next step to check the injector.

Yes, I would soak the pindle in carb cleaner. try that first

Roy

I didn't see that you said you recommended to do that. I only saw it was something to maybe try. I'm sorry.

I will soak the pintle but do you think the EGR sensor A circuit low could be a bad EGR? Only trying to help.

the pindles load up with carbon chunks and hold it open. it will then run lean and cause a misfire from a vacuum leak.

Roy

Do you think the EGR caused a vacuum leak somewhere since it was caked with carbon?

yes, when the valve is open, that is a vacuum leak, a big one.

Roy

Oh! I didn't know you meant the valve IS potentially the leak.

Do you assume the cylinder 2 issue could be the injector? Would that cause the running rough issue potentially?

If the EGR is even partially open when it shouldn't be it will let inert exhaust gases into the engine and cause symptoms similar to but worse than a common vacuum leak. With a normal vacuum leak you get a lean fuel/air mix. Usually it will still ignite but you don't get the same amount of power. With the inert gas from the EGR you get a mix that doesn't ignite or only part of the fuel burns. Both will cause random misfires and loss of engine power as well as hard starting. The first thing I would do would be a top cylinder cleaning to break up as much carbon as possible. Next would be to pull the EGR and use a flexible brush and wire to clean carbon out of the passages in the intake. Then run it a bit with the EGR removed to blow out as much of what you loosened up out of the intake. Clean the EGR but be careful as you can damage them if you get aggressive. Order a screened EGR gasket (Kleen Screen or similar) and install it. Clear all of the codes and run it a bit to see what returns.

The EGR issue alone will cause rough running and misfires so it needs to be the first repair.

The B codes are all airbag and SRS related.

I kind of figured that, Steve. Thanks so much!! I will try to get a screened gasket today. I soaked the EGR in throttle body spray and some more black came out. I'll drive without the valve on and go get the codes cleared first as well.

The flashing service engine soon light I was told meant I shouldn't drive the truck and another person told me it meant misfire.

CRC Motor treatment slowly through the brake booster hose while running is ok? The truck has O2 sensors and a cat converter.

Don't drive it with the valve off, scrub the passages and run it with the valve off just to blow out the chunks that come free. It will run like crap but you don't want to blow the carbon through the rest of the system if you can avoid it.

Flashing SEL/CEL actually means there is a problem that could damage the converter. There are a few things that can be, the primary one is a misfire as those dump raw fuel into the converter and they are not designed for that. It can easily cause them to burn out or glaze over inside.

I prefer seafoam or GM top cylinder cleaner as it seems to do a better job than most others.

After doing the top cylinder clean with Sea Foam it smoked bad. After driving it slightly hard it does run better but still hesitates under acceleration and shakes intermittently. I was going to let it soak overnight but then saw hydrolocking is a concern so I turned it on after about 2-3 hours of it hot soaking. The CEL no longer flashes but is still on. I didn't drive it far. I was considering clearing codes to see where we are. What do you think?

I got a regular EGR valve gasket as I would've had to order a screened one. I didn't put it on yet though. I guess I'm waiting to see if I need a new valve.

You could also try GM top engine cleaner. We use that all the top and it works great breaking up the carbon.

Roy

Yep, good stuff. The smoking is normal, it is the cleaner and carbon burning off. Clear the codes and see which ones come back.

I just saw that I should possibly try to put something into the engine ports where the EGR bolts onto to make sure it isn't clogged. Is this true?

What I do is with the valve removed, I start the engine. you should have a large exhaust leak and also a vacuum leak. the engine may stall or run rough. that will tell if you have signals to the EGR

Roy

If the engine runs normal and correct with it off, EGR is bad?

no, the passages are blocked.

Roy

I just took it off and three times the engine immediately shut off. The ports in the engine look completely solid. Am I to assume the port holes go off to the side?

Did you have a good exhaust leak when you pulled it off?

I cannot tell. The engine shuts off so fast. Should I run the truck to running temperature first then remove it and restart?

you should hear a loud exhaust. if you remove the valve, it should have a large exhaust leak.

Roy

It was loudly sucking yes.

loudly sucking is the vacuum. the exhaust would sound like you had no exhaust on the car.

Roy

The engine was not louder than normal, I do not think no.

Okay, then you have a clogged exhaust port to the EGR valve. without that exhaust the valve cannot work.

Roy

How do I clean it? Maybe a bent wire brush into the port from the throttle body side or from the EGR side?

There is an exhaust tube from the manifold that goes to the valve. that is the port that needs to be cleaned out.

Roy

Can I get to it from the EGR ports on the engine and do I have to snake a cable into it to "drill/ream" it out? Thanks.

yes, once you remove the EGR then you need to clean the passage to the exhaust manifold from the EGR port.

can you post a picture of what you see?

Roy

Here is the EGR ports. Which hole do I clean out with a cable, etc? I cannot see the hole in the throttle body yet. Is a speedometer cable best to use in a drill?

Both holes, they are completely clogged.

Roy

I've done some "drilling" with a speedometer cable on both sides but when running truck with no EGR it will run rough like it's going to die then come up in rpm and keep cycling like that. It does seem slightly louder now but I think there's still gunk in both the intake and exhaust valve of the engine EGR ports. I may need some more tips to get the carbon out. I still can't see where the carbon is in throttle body.