So I've been experiencing some "fluttering" recently. Once the car warms up it flutters or jerks (slightly) when holding the speed at about 40mph (1700 rpm.)

I removed the hose from the EGR valve and plugged it and that made the fluttering go away when driving it so I figured the problem was probably the EGR valve or ports ... so I purchased a vacuum pressure gauge to test it.

When I hook it up to the valve and apply vacuum, the engine sputters so I figured the valve and ports are working properly.

When I hook the gauge up to the hose (instead of the valve) and increase the rpms to about 2000 or so, the gauge registers vacuum for a split second and then drops to zero. This makes me think my solonoid (located in the control box) is bad.

I'm not very knowledgeable when it comes to mechanics so I'm probably missing something. Any thoughts on this? Any help would be appreciated. Thanks.

 

I also got a quick split second drop to zero on my 90 ex.
Only during a road test could I see a steady vacuum of 3 to 4" on the vacuum gauge which I had on my passenger seat via a long hose teed into source vacuum line to the EGR valve.
I would say that that split second vac reading is normal with the car in Park.
You may need to clean your EGR valve and intake runners.

 

what's the year/engine/transmission?

 

It's a 1991 Honda Accord EX - 4 door - 4 cylinder (I think I recall them saying 130hp engine) - Automatic transmission.

@9DEX ... Clean the EGR valve/ports? Why? When I apply vacuum to the valve at idle, it works properly ... it's supposed to stumble and try to stall if working properly ... right? The test called for applying 8" of vacuum to the valve.

From your reply (9DEX) it looks like I'll have to test it while driving so I'll need an extension for that hose. Thanks, for your reply ... I was dreading hearing "you have to be driving it" but in my heart it's kind of what I figured.

I'll do that test and come back to post later.

 

I bought some hose and extended it from the #16 hose into the passenger seat ... hooked up the vacuum gauge and went for a spin. Brought it up to operating temperature and tried holding it steady at about 40mph (1800 rpm.)

There was not a stitch of vacuum. Never registered at all.

I brought it back and let it idle for a few mins and took another spin. This time, as I put it in drive and headed down the long driveway, it registered about 8 inches as I was creeping along around 10mph. Stopped at the end of the driveway and accelerated out onto the road. Vacuum held steady at about 8" ... for about 15-20 seconds then dropped to zero.

I held the speed steady at 40mph but no vacuum registered again. Brought the car back to the driveway and parked it. Revved the engine a couple of times ... no vacuum.

Sooo, there it is ... any thoughts?

I'm going to guess it's either the solonoid or the main computer.

 

its not your ecu, the computer has nothing to do with generating or maintaining vaccum. if the solenoid valve is out of spec, a code 12 ought to be thrown. Keep in mind when EGR is operation, is in cruising near idle speed. When not, the solenoid cuts vacuum applied to the valve to prevent gassing, which by your statements it seems to be doing. If you are getting stuttering at cruising at X rpm under load, I would begin with inspecting your ignition system for faults first.

 

Hamster, thanks for the reply but when cruising anywhere between 35-45mph there is a slight fluttering ... a sort of jerkiness in the engine ... not quite as detectable at higher/lower speeds but still seems to be present.

Perhaps you missed the setion where I said that I removed (and plugged) the #16 hose from the EGR valve and all the "symptoms" went away. That's what leads me to believe the problem is in the EGR system somewhere. And I think the ECU is involved at some point in making the calculations about when to open the EGR valve.

My main question at this point is:
Is there supposed to be vacuum coming from the #16 hose when cruising (light throttle) between 35-45mph (roughly 1600-2000 rpms.) Because mine is showing ZERO.

 

Sorry, I'm easy to confuse.....you unplug the vac line and drive the car and everything is fine...correct? Then you worry there is no vac on the hose while driving and you have issues?

Did/do you see vac on that hose at anytime?

 

POORMAN212 -- Thanks so much for the reply.

The answer is yes, I did see vacuum on that hose but it did not operate in a way I would have predicted.

When I hooked it up while under the hood I'd push/hold the accelerator with my hand and hold it on about 2,000rpm ... and the vacuum would go up to about 8" for a split second and then drop to zero.

Then I bought some hose and extended it from the #16 hose into the passenger seat ... hooked up the vacuum gauge and went for a spin. Brought it up to operating temperature and tried holding it steady at about 40mph (1800 rpm.)

There was not a stitch of vacuum. Never registered at all on the first go-round.

I brought it back and let it idle for a few mins and took another spin. This time, as I put it in drive and headed down the long driveway, it registered about 8 inches as I was creeping along around 10mph. Stopped at the end of the driveway and accelerated out onto the road. Vacuum held steady at about 8" ... for about 15-20 seconds then dropped to zero.

I held the speed steady at 40mph but no vacuum registered again. Brought the car back to the driveway and parked it. Revved the engine a couple of times ... no vacuum.

When I hook the hose up to the EGR though, the car will flutter after it warms up ... when I'm cruising it at light throttle ... and it's most prevalent when I'm trying to hold the speed between 30 and 40 mph (roughly 1500-2000 rpms.)

And, you're right ... if there were no vacuum, how would that be different than unhooking the hose.

Answer: No difference I can see ... therefore, if I have no vacuum then I shouldn't have a problem.

What I thought I was going to find was that the vacuum was coming on but only holding for a split second and then dropping -- causing the fluttering -- but that's not what I found at all.

I just don't get it. I thought "well, it's probably not the EGR valve itself because I applied vacuum to it directly with the gauge and it seemed to operate properly" ... i.e. it held vacuum and the engine wanted to sputter and stall.

This whole thing is giving me brain damage ... and I don't have much brain to play with.

 

I would say your EGR system up the EGR valve is all operating correctly. I got very similar vacuum readings and they were low and intermittent.

First, I would verify that all your tune up items are within spec.


Next, I would remove your EGR valve and the Intake manifold port plugs.
There are 6 plugs total. Pull the 4 easy ones first and have a look to see how much blockage there is from carbon build-up. Clean out everything that you can get to. Uneven blockage may cause the cylinders to receive different amounts of exhaust gas and therefore cause an imbalance in the power the different cylinders produce which may be the cause of your drivabililty problem.

There is a good write up online on how to do this job. It is a common problem on accords from 1990 on. I had to do this on my 90 because it failed a smog test due to high NOX. The car ran much better after this clean out.