I just bought a 91 Accord(5 spd) for a song(its a exact match for my 91 accord with a bad engine, the tranny is bad), I drove it 200 miles home yesterday, so I've done a pretty thorough evaluation of its performance.

The temp gauge is perpetually stuck about a 1/3 through the gauge when on, the car misses at all speeds, unless you are actively accelerating, then it runs awsome.

I assume it is a bad sensor, and naturally I assume its the temp sensor. I drove my original 91 for 8 years with NO sensor problems, so I'm looking to the experienced CB enthusiasts for a point in the right direction here.

Thanks in advance!

 

I would find out why is running cold first. Thermostat stuck open or wrong temperature? If it runs in closed loop all the time it will run richer which could cause carbon buildup.

BTW I love Bandon Or

 

Inspect the secondary circuit such as worn contact points inside the distributor cap, worn rotor, pin hole on the plug wires, crack distributor housing, wrong spark plug gaps, wrong spark plug heat range, and your ignition timing to see if it's in the right spot.

Also, make sure that all your injectors are clicking by listening through a screw driver to each of them. And I'd use soapy water to spray around the injector o-ring while the car is running to see if you can see any bubbles which will cause a misfire as well.

 

nus_dogg- I found a receipt and a return receipt for a distributor in the glove box, so it looks like someone already tried that route. I do have a perfectly good distributor in the other car, so I may swap it out to be sure.

I suppose if I don't find a easier fix, I'll just swap out the entire intake manifold assembly out of the original car, it was running great.

Nicefeet- I have noticed that the heater kicks in very fast after starting the car cold, this may be a symptom of a bad thermostat? But even long after the engine should be warm, it still misses.
Part of the reason I suspect the sensor may be bad is because sometimes when first started the temp gauge shows negative cold(the needle swings backward behind the normal cold starting point).

Anyways, thanks for all the advice so far! Now I need some days off work......

 

Hmmmm, plugs(autolite double platinum), wires, and distributor cap all look good-great, I have a feeling these were replaced during the previous owners quest to fix the problem. The plugs were all the right color with no fowling. I might go ahead later and replace the whole distributor assembly with the one from my original car if I get stuck on the other possibilities.

Tomorrow I'll check out the thermostat(I had a new one on hand for the old car), and make sure the coolant system is bled properly. Then I'll check to make sure the injectors are all working(per nus_dogg's advice).

I've read elsewhere that bent valves may also make a engine act like this........please lord NO!!!

 

With regards to the temperature gauge being off, I would get a new temperature sender. It is located on the cylinder head below the distributor. There are two sensors there, one is a the coolant temperature sensor and the other is the coolant temperature sender. The sender has the "gauge" type.

 

Sweeeeet! I bled the air from the coolant system by running the car with the radiator cap off, about 2 minutes after I turned the car on it made a sudden change in engine sound. I took it for a drive, and low and behold, the rough running while idling/coasting was over!

For the hell of it, I listened to the injectors through a screwdriver, they were all clicking. I've got a 30 mile drive to do in the morning, so I'll be able to completely evaluate, but I think that problem is fixed! Thanks to all!!

Now I'll be swapping out the trunk lid with the ridiculous aftermarket spoiler, and the transaxle from my all stock original 91 Accord, not bad for $600!!

 

A lot of times you can just shake the car up and down until the air bubbles all break free.

Good job.

 

First off, I understood very little about my original running problem, calling misses at all speeds was not accurate. Let me lay out my problem again, I know I announced earlier that bleeding the system seemed to fix it, but it didn't.

The car runs rough, even after it is defiantly warmed up(runs decently while warming up). The missing is mostly while cruising under 2500 RPM, much less (or more often not at all) while accelerating, especially at highway speeds. As soon as foot lets off the gas, the missing starts again.

After driving the car 15 miles to work, turning the car off, then 5 minutes later starting again, the car will sometimes act like it will start then dies immediately. Waiting 1-2 minutes to crank again will start the car right up and off you go.

The driver side fan will stay on for 10+ minutes after turning the car off. But if after it goes off(even with a cold engine) you turn the ignition on without starting the car, then switch it off, the fan will come on again for 5-10 minutes. I did this several times over the course of a hour today, WTF?

Another weird thing with this car is that the running lights all come on whenever the ignition switch is 2. The headlights on bell comes on at position 1, even with headlights off. Not sure if this last thing has anything to do with the running condition, but I am starting to suspect gremlins in the wiring...........

At any rate, I swapped out the coolant sensor under the distributor, with the one from my old Accord(not sure it works either), bled the coolant well, still running rough.

I have 2 working ECUs that will fit this car, but I really don't think thats it....

 

Check/test thermo b on the upper hose.

have the egr ports been cleaned?

 

Thermo B is probably bad, and not related from the problem at hand, but I don't want to leave out anything even remotely related.

EGR ports? Never had this one suggested by anyone before, but I'll try anything at this point.

I've been dragging my heels on digging into the intake manifold, but too many possibilities keep turning my attention there. Guess I better order a complete set of gaskets and set aside another day or two, and tear into that beast.

So clogged EGR ports could cause this?

 

[QUOTE=oregonorganic76;45159679] The driver side fan will stay on for 10+ minutes after turning the car off. But if after it goes off(even with a cold engine) you turn the ignition on without starting the car, then switch it off, the fan will come on again for 5-10 minutes. I did this several times over the course of a hour today, WTF?
[QUOTE]

Thermo B would be what I would test first for the above.

I'd think about the plugs, IMO NGK would be the brand I'd go for, I know they "looked" fine but.... - just opened myself up for a flame. I know the Autolite's look good but trust me I've seen people have issues with them.

There was no oil inside the plug tubes and or inside the dizzy (phoot, that was for you).

 

The plugs in the car were double platinum Autolites, the most expensive plugs I have ever owned(they came in the car), I have no brand loyalties, what ever brand I grab first always does what it should, in 20 years of driving Hondas(starting with a 77 Accord, ending with this second 91 Accord) I have never used plugs this fancy before.

By saying the plugs "looked right", I mean the plugs were the right color for slightly used plugs. They had no indications the engine itself had any problems. They gapped right, etc.

I have not checked the timing yet, but otherwise I don't believe this is a spark problem, I went through all of that 5 years ago with my first 91 Accord(bad ignitor).
I've ordered a new thermo sensor, and the sensor for the one fan, and gaskets for most stuff in the intake manifold, so I can clean it. Its got to be here somewhere.

Yes, the fans temp sensor is bad, I included the description of its problem in case it might indicate a greater problem thats not so common sense(messed up wiring or ECU).

 

Wow! I wish I had checked the timing earlier! Last night I got my brand new timing light out just for ***** and giggles( I bought it for tuning up my 81 Datsun pickup), followed Chiltons instructions for my car(jumped the test harness, etc). But when I shined the light in the window, I see no timing marks at all, not even in the neighborhood, what gives? How could the car even run at all with the timing so far off? Is it possible? I don't think I'm doing anything wrong.

I suppose I'll get into my chilton manual and manually turn the engine tell the timing marks line up, and go from there.