94 Accord stumbling on accel

transmissions

#1

Hi all. My 94 accord ex just started stumbling on acceleration and feels like it’s missing when traveling at a constant speed. It’s more like a chugging when driving at a constant speed and it goes away as soon as I accelerate or take my foot off the gas.



The car shifts fine. There is no abnormal behavior or missing when I rev the car in neutral. All fluid levels are fine and the tires are fine as well.



I’m thinking it’s something in the suspension, like a ball joint, wheel bearing or CV joint because I hear a thumping from the passenger wheel that corresponds to the chugging/missing feeling. Could it be a suspension component?


#2

Just want to add that no check engine or check transmission light is on.


#3

Get it to a good mom & pop mechanic and let them take a test drive/listen. A skillful mechanic should be able to diagnose this.


#4

Ok, just got the car back from a (somewhat) trusted mechanic. They replaced both control arms because they claimed the ball joints were bad. The chugging/stumbling/vibration is still there. I don’t think a bad ball joint would cause my problem; I think something closer to the transmission would be at fault, like a hub and bearing, cv joint, or something else. Anyone else have any ideas before I take it back and have them look at it again?


#5

Can’t narrow this down without doing some tests…especially, fuel pressure tests. I think it has a misfire problem.
Ensure that the routine maintenance is up to date: replaced fuel filter, replace spark plugs and wires, replace distributor cap and rotor, pcv valve. Then, if there is still a problem, do the fuel pressure checks under various engine conditions (unloaded, loaded, low rpm, higher rpm).


#6

Ok, an update. In neutral, I can rev the car up to the redline and hold the RPMs at a steady value without any problem. If I put the car in drive, keep my left foot on the brake, and gently apply gas, I can feel the transmission shuddering at ~1700 RPMs, which is where I also feel the shuddering/stumbling when driving. So, it’s something in the transmission. It does not happen when I accelerate briskly or when I’m coasting; only when I’m driving a constant speed. Can one of the transmission experts here tell me what may be causing this problem?


#7

Ok, I did some more research and people in the Honda forums suggest that it might be a clogged EGR valve. Does this sound reasonable and wouldn’t a clogged EGR valve set a check engine light?


#8

Please advise. Thank you.


#9

I replaced the spark plugs not too long ago and the wires are about two years old; both parts were replaced with Honda parts. Would not a misfire be detected when I rev the car in park or neutral?


#10

I wouldn’t be doing that stall test (of taking the engine rpm up to 1700, in Drive, while the car is stationary). On a newer car, it wouldn’t hurt; but, on an older automatic transmission, it could hurt it (eg. cause the clutch plates to slip and wear them to metal – not good).
The mechanic, still, needs to do the fuel pressure tests: drive the car to 1700 rpm while monitoring the fuel pressure. The mechanic should be able to tell if the shuddering is caused by the engine or transmission.
There may be misfire. Did you change the distributor cap and rotor?
A little misfire won’t turn on the check engine light. A lot, may. You can’t sense the occasional, singular, misfire. All engines have some of this.
If there is a DTC code in the transmission, the D4 transmission gear selection indicator, on the dash, will flash. If it flashes, the DTC code can be had by shorting the 2-pin connector, under the edge of the glove box, with a straightened paper clip, and counting the flashes (1 through 14).
If your mechanic(s) had, and used, the repair manual (Chilton’s, or Haynes), he/they could use the instructions in that to check the EGR Valve, the other valves, and the sensors, with a digital multimeter.
You may need to switch to mechanics who have more diagnostic skills, and are proficient with a multimeter.


#11

Understood on the stall test. Wouldn’t a misfire condition be felt regardless of what gear the car is in, i.e. shouldn’t I feel the vibration when I rev the car in neutral as well as in D4? Also, the transmission selector is not flashing. I have not yet asked the mechanic to inspect the EGR valve and solenoid; I was asking whether it would be possible that a clogged EGR valve or EGR ports could cause the symptoms I’m experiencing.


#12

I can’t see a plugged EGR valve causing stumbling at a certain rpm. The engine will run a little richer. Engines love a rich mixture.
Perhaps, this article will enlighten you on the role of the EGR valve: http://www.asashop.org/autoinc/dec97/egr.htm


#13

Just curious, do you have a manual and did you recently replace your clutch?


#14

No, I have an automatic. I still have to take the car in but I’m thinking it’s the CV joints.


#15

I would be let’s just say disapointed to pay for control armrs that did not solve a “chugging” sympton but thats just me. Are they going to make it right in regards to repairs you did not need? Don’t let me instigate anything but the situation stinks.