pgm-fi on and excessive blowby

[kentwat]

My 86 LXi has been giving me this code 12 egr for over a year. I still get 30 mpg. I have swapped out egr for another one and no change. I tried applying vacuum to the egr while running and it kills the motor. From reading posts people says that means it is good. Car just rolled over 279000 miles and still uses no oil. But lately after interstate driving on the off ramp smoke will start coming out from under the hood. Quite annoying and embarrassing. I'm guessing this is due to egr passage clogged up. Has anyone tried drilling the holes out to the egr passage, cleaning it out and then resealing holes? Any tips would be appreciated. I enjoy this accord but the smoke coming out from under the hood it just killing me. I don't like taking my daughters to school with this condition either. Thanks Kent

[Dr_Snooz]

I suspect the smoke is unrelated to the EGR code. You just need to get in there and find the problem. If it's blowing a lot of smoke, it shouldn't be hard to find the mess.

The EGR system involves several different components, any of which could be failing. Get the manual available here and run through the troubleshooting procedures. Crudded up passages is certainly high on the list of things that can go wrong. I've had the work done and it's doable, but a pain. I think it's something that would make you fail smog more than something to turn the light on though, but that's all I know about it.

Keep us posted on what you find.

[ecogabriel]

My 86 LXi has been giving me this code 12 egr for over a year. I still get 30 mpg. I have swapped out egr for another one and no change. I tried applying vacuum to the egr while running and it kills the motor. From reading posts people says that means it is good. Car just rolled over 279000 miles and still uses no oil. But lately after interstate driving on the off ramp smoke will start coming out from under the hood. Quite annoying and embarrassing. I'm guessing this is due to egr passage clogged up. Has anyone tried drilling the holes out to the egr passage, cleaning it out and then resealing holes? Any tips would be appreciated. I enjoy this accord but the smoke coming out from under the hood it just killing me. I don't like taking my daughters to school with this condition either. Thanks Kent

If engine gets killed when applying vacuum to the EGR valve then the EGR passages are probably (probably) OK. That does not mean that your EGR valve is OK though; the electrical part may be faulty.
There is wiring on top of the valve; there is a sensor there that tells the ECU the position (closed, open, and how much open) the valve is. If the sensor stops working the ECU cannot see the valve opening and then throws a code.
So there are two tests: one is for holding vacuum and the other is for measuring the sensors.

[kentwat]

Thanks for replies. That is a good observation about the ports not being clogged when vacuum kills the motor like that. I guess I'' break down and get a new egr. As for the smoke I'm going to pull that black catch jug under the intake for the pcv. Maybe it is plugged and needs to be cleaned.

[Dr_Snooz]

Thanks for replies. That is a good observation about the ports not being clogged when vacuum kills the motor like that. I guess I'' break down and get a new egr. As for the smoke I'm going to pull that black catch jug under the intake for the pcv. Maybe it is plugged and needs to be cleaned.

Stop! Do NOT go easter egging. Follow the troubleshooting procedure in the manual. If you spend a fortune on a new valve and the problem ends up being the EGR control solenoid valve in the black box that you could have replaced for $12 from the junkyard, you're going to feel silly. And broke. (Ask me how I know this). Throwing money blindly at your car is not going to fix it. You have to find the problem first. It could be as simple as a disconnected vacuum line. Take the time to do the procedure outlined in the manual. It could save you $250 on a new EGR valve.

K thx.

[ecogabriel]

Stop! Do NOT go easter egging. Follow the troubleshooting procedure in the manual. If you spend a fortune on a new valve and the problem ends up being the EGR control solenoid valve in the black box that you could have replaced for $12 from the junkyard, you're going to feel silly. And broke. (Ask me how I know this). Throwing money blindly at your car is not going to fix it. You have to find the problem first. It could be as simple as a disconnected vacuum line. Take the time to do the procedure outlined in the manual. It could save you $250 on a new EGR valve.

K thx.

Check before replacing anything and read the repair manual. If you have a vacuum pump you may also have a multimeter; the ECU does not command the EGR directly but uses a solenoid that sits in the black box. That solenoid may be shot or there may be a vacuum problem not reaching the valve. The valve does not work on intake vacuum but on regulated vacuum (those parts are inside the black box).
Even if the EGR turns out to be defective, armed with a vacuum pump and a multimeter you may find a good one in the junkyard if you know how to test it. I did that and worked fine although I had to guess the electrical testing.

Bottom line: take it easy and take your time to understand how the whole system works.

[kentwat]

OK, I've had the box apart once, I saw that the egr vacuum line goes to a valve and then to the solenoid. I need to get a new end for my vacuum gauge so i can test smaller lines. When it was hot there was vacuum coming down the line to the egr but I can't tell how much. I'll go through the manual troubleshooting egr again. Thanks.

[Oldblueaccord]

If your getting 30 mpg and not needing to pass emssions I would just not mess with the EGR.

I am betting the smoke under the hood is oil leak getting on the manifold or exhaust pipe.


wp

[w261w261]

How much smoke are you talking about? Clouds? These engines are famed for their oil leaks from a few places (valve cover gasket, oil filter housing, cam covers, oil pan). You might want to go underneath, take off the plastic splash shield under the motor, get some engine cleaner, and get rid of all the oil. Then drive it for just a few miles, and quickly go underneath again and see if you can see the leaks. As the previous poster said, they can drip on the exhaust and make good smoke. Put the ventilation on "recirculate" and the cabin will smell better.

[kentwat]

Thanks for the tips. Ya no inspection here. The light just annoys me. As for the smoke I'll check for leaks. It never leaves any puddles or anything but I will go under and check it out. Smoke level is just a little bit so people next to me will see it. The egr I did find the sensor in the box I believe is for egr. EGR hose goes to a valve and that valve goes to a sensor with a couple of wires.Thanks all I report back with findings. btw, I've always had to use recirculate on the air vent due to smell.

[car6289]

Kent:
Another smoke generator suspect could be the power steering hose that runs from the PS pump across the front of the engine. Coincidentally it runs almost directly over and just forward of the exhaust manifold. Rubber+heat+time+3G=leak

[kentwat]

Smoke is coming from the valve cover in front. It looks a bit nasty. Can you clean out the pcv catch can under the intake? Any one tried it? As for the egr issue I ended up getting a complete black box that hasn't been messed with. I swapped out everything one at a time except for the electric hookup that controls the 2 vacuum ports. Thinking as I am writing this could be the culprit since it controls the two electric vacuum devices.

[Dr_Snooz]

Can you clean out the pcv catch can under the intake? Any one tried it?

Never tried it. God only knows what's lurking in mine. I just use good, high-detergent oil (Mobil 1). That tends to clean just about everything to a high shine.

[kentwat]

Well I swapped out the final electrical part in the black box. It hooks to both vacuum controllers. It runs well but the pgm-fi light will come on after shifting to fourth on the road. In the manual I do not see where to test the electrical part of the egr. Any tips or pointers on that. I'm going to read through it again.

[ecogabriel]

I'll go from memory here as I never documented this.
I had a code 12; the EGR valve solenoid worked OK. I decided to check EGR valve sensor; the EGR connector has three wires. Since the ECU uses information from the sensor on top of the valve to "see" how much open the valve is I figured that I had to see some variation in readings when applying vacuum.
To make a long story short: took my valve, hook up the vacuum pump, attach a probe from the multimeter to the middle wire in the EGR valve connector while the other was attached to one of the "extreme" wires. Set the multimeter in the ohms scale to sense continuity.
If the EGR valve is OK you will see that as you apply vacuum (go inch by inch) the reading from the multimeter will change. Once done the "center-one end wire combination check the other "extreme" using the center wire as before. You need to check both "extreme" wires in the EGR valve. I remember the readings being different for both sides; I think one side goes up in resistance while the other goes down according to variations in vacuum.
If one of the "sides" has no reading then the valve position sensor is busted. Myown busted valve had no reading whatsoever in one of those readings while the other side had readings. I checked two or three different EGR valves in the junkyard and those have a similar problem until I found one in which I had readings from both "sides". that's the one in the car right now and no more code 12 (and the f... pinging also disappeared)

I am away for the weekend but I'll try to document the testing shortly. I need to make sure that I'll know what to do if I get the same problem again, and that it would be documented somewhere

[kentwat]

Great info thanks. I'll give it a try. I have a 90 Integra I just picked up. It had code 12 also. The vacuum pod was busted so it wouldn't hold vacuum. I swapped on my original from my accord cleared the codes and it again pulled code 12. I'll hit PAP today and try again. Thanks.

[ecogabriel]

My junkyard experience with EGR and solenoids was that one needs to test them as most are f...up. Two/three of the EGR valves I picked up held vacuum but had their sensors not working.
I got solenoids for the A/C idle boost valve and I opened several black boxes (EFI and carb) and most solenoids were dead. Eventually managed to find two that worked (I checked the electrics for continuity) installed one and kept the other as spare as I have two solenoids in the black box that are similar (cold vacuum advance and the A/C booster)
With patience you'll find working parts but the key word is patience.
As I said, I'll try to reproduce what I did for testing the EGR electrics later.

[Dr_Snooz]

I had real good luck with the junkyard for my EGR problem. My 4g was flashing CELs at high altitude. A $12 control solenoid from the black box fixed it perfectly. That was over a year ago and still running strong. It was somewhat of a calculated risk. I'd never heard of a control solenoid going bad so figured a junkyard replacement would be fine. It was.

[kentwat]

I went to the jy picked up another egr valve. I haven't had a chance to put it in. Hopefully tonight. As for the control solenoids, I had 2 of them. I put the multi on them on ohm scale and one didn't even change from 1 on the scale and the other did show continuity. I just went out to test the 2 on my car and both showed continuity. One had a higher number than the other. I verified now what each one is for cold idle and ac boost by following numbered lines. But if it turn on the ac it will still drop down the idle to 500 rpm. The solenoid on the car that moved alot was the boost valve solenoid so I may try and swap with one that test ok.

Just curious as to why my car also has the A/T boost valve when it is a manual? How knows emissions trying to save fuel?
Here is another what is the piece called hooked to hose 17? I've looked through the manual and my best guess is for cruise control. Heres a pic.

Thanks all for input.

[ecogabriel]

The one that tested "1" is probably dead; I picked up mine based on reading continuity.
As for the idle speed falling when A/C is on you may still need to adjust the A/C idle control valve. it is located on the intake manifold on the side closer to the timing belt (driver's side). When the solenoid is energized, intake vacuum opens the booster valve and extra air gets into the intake; the amount of air allowed in depends on the adjustment of a screw in the base of the valve.
I wrote up something a while ago on how to troubleshoot the A/C idle boost system and adjust that valve.

The one piece you have with the connector and wire attached is the EGR valve solenoid. When that is open vaccuum cannot reach the EGR valve. When it closes (closing hose #17 communication with the filtered air before the throttle body) vacuum forms in the line and the EGR valve opens. Try plugging #17 with engine at idle; if your EGR valve holds vacuum the engine will start to fail and eventually die.

A/T booster solenoid in a manual? Maybe the transmission was swapped before you got the car or someone swapped the whole black box instead of troubleshooting it...

[kentwat]

Thanks for info test results after a couple of minutes it did start to run poor at idle. The exhaust definitely sounded rough. I did pull the #17 vacuum line and it was holding vacuum. I plugged it back in and then shut it down. I then pulled the egr line again and vacuum was present again. It popped. Then I heard a valve release vacuum in the box. I'd suspect the green valve.
Here is a pic of the setup.


Map sensor on left, I thought that was the A/T control valve next, then the small vacuum pod white in back, ignition solenoid cold idle, egr solenoid valve I did have continuity on it, and the another solenoid behind it A\C.
Any corrections or info would be much appreciated. I need to search the above article now. Thanks Kent

[ecogabriel]

The "dish shaped" thing produces a steady vacuum (about 7in) regardless of engine load. That way the cold advance, A/C boost and EGR valve have a predictable action.
I wonder what the metallic cylinder is for; the idle booster in mine (automatic) is a far bigger thing.
On the other hand, there should be a small white plastic bottle that sems to distribute distributes vacuum; if I remember right it is related with the EGR system too.
You may test the EGR solenoid you identified by applying battery voltage; it should be closed when energized.

I still have to do my check on the EGR valve itself; I suspect your problem is probably there because the valve position sensor is one thing that may wear out... hopefully I'll have some time this week.

[kentwat]

I was at the junkyard today. 88's have a different black box setup. All of the 86 fi's are gone unfortunately. I'm pretty sure the metallic one is the cruise then since you identified the other as the egr solenoid. I do have that vacuum "dish" You can see it in the back of the metallic sensor. I have swapped it out with another and this one seems to hold vacuum better. I still have another egr valve to try also. I haven't applied and battery power to the egr solenoid either.

as as sidenote: There was a set of 14' rims off another honda but someone got them. They were like a directional. I was a bit irratated since they were 25 a piece and had decent tires. There are also a 14" set on a 94 Mazda Protege with decent tires. Alloy with 5 holes. Supposed to be 4x100 according to discounttirewarehouse??? Have a good one.

[ecogabriel]

88-89s have some differences in the black box. Can't recall exactly but there may be a purge solenoid for fuel fumes and another to command the two-stage intake manifold those models have -they make an extra 10 horsepower than ours :-(

One of the small lines brings vacuum from the intake manifold; that dish-thingy converts that vacuum into a steady 6-8inHg (can't recall exactly but if you have about 7 you should be OK).
Tinkering with the black box was the first thing I had to do with the car when I got it 1 1/2 years ago. Once I replaced the A/C solenoid I never opened it again so I am a little rusted on what is in there. Besides, the manuals available are for european accords whose emission systems are different (if at all). And the one for '89 accord is, as you pointed out, a slightly different setup. But at least you may track down the EGR system from that one.
I wanted to do the EGR testing but it is raining... crap!

[ecogabriel]

I'll try to post a more detailed description on how to test the EGR sensor later; I did some testing and took a couple of photos a few days back but things have been crazy over here.
In short, when the EGR valve wiring is unplugged, looking inside the connector attached to the EGR valve one will see three contacts.
Using the multimeter in the ohms scale one probe has to go to the center contact and the other to one of the end contacts. Also, a vacuum pump is necessary to test. By pulling vacuum SLOWLY (1in Hg at the time, no more than 7-8in Hg is necessary) one can see how the ohms scale starts changing. One "side" will start showing more resistance as vacuum deepens, whereas if one is probing the "other side" (center-the other end) the resistance diminishes.
It is a bitch to keep the probes together to the contacts and pull vacuum at the same time; getting an extra connector from another car in the junkyard (cut it from the engine wire that goes to the EGR) may make the testing easier.
A working EGR will show a pattern of one side w/increasing resistance as vacuum is applied while the other side shows diminishing resistance. If no reading can be seen in either side or it shows discontinuity then the EGR is most certainly defective.
Hope it helps and apologies for the messy response...