Hi everyone

My beloved 1992 CB7 EX has been giving me the worst of his problems ...

It all started with major engine failure and codes 43 and 1 on the self-diagnosis.

Oxygen sensor replaced, I thought that would be the end of it, comes out it was a no-no.
It's better but not quite perfect.

When the engine is cold it goes through tremendous trouble to start. The engine turns, turns and goes nowhere, just doesn't fire up.
It soaks in gas so much it smells all over and then eventually will start in a very shaky and "coffing" way.

Trying to eliminate the possibilities, new spark plugs were installed, new gas filter, new air filter and new spark cables as well.

Still, the sympton persists.

It seems that if its a hot day there's less of a fight to start but if it's morning or nighttime, it really struggles to kick off.

My mechanic went off to buy the required tool to measure the fuel pressure just to make sure ... if it clears ok ( with proper pressure values ), we're sort of out of "where to look for the problem's source".

Any ideas ?

Just to be accurate, mine's a CB767 with F22A6 engine and auto trans, engine's already been rebuilt two years ago.

Thanks for your help.

Pete

 

Will it spark at all?

Test the sensors in the distributor - #1 position sensor for sure. Also, is the inside of the distro (under the shield near the sensors) full of dust or debris?

Did you get a new distro with the new engine?

 

It does spark.

Struggles on and on until it does but it sparks.

Yes, did buy a new distributor ( and new external coil ) when engine was rebuilt.

 

Please explain "major engine failure". Thrown rods,cam lobs worn,oil pump,timing belt? Those are major engine failures.

 

So she's running a bit rich you think! If that's the case then it's not going to take long before you foul that new O2 sensor as well. Sounds like there may have been an ongoing prior issue. So if you are running rich there is probably a fuel issue.

However before we get into that, what did you end up setting your TPS closed throttle voltage at? Also you can hook up a scan tool to verify. You should be reading 8-10% throttle @ idle (700±50 rpm)

 

Thanks for your attemps so far.

HonBeer, by "Major engine failure" I mean that when working, the engine hesitates, chokes and doesn't idle percectly. Many times, when running ( especially when still cold ) it's like when someone's coffing or with hiccups.

I think that's the best I can explain that ...

GhostAccord, I ended up swapping the full throttle body for another ( used ) one I bought on the eBay. It's working perfectly, I chose to install this one as I couldn't get a reading on my multimeter, so I just dropped the whole issue and installed an original part still in its factory setting.

One piece of information that might be usefull ... sometime ago, when we were still fiddling around with the TPS position, we left it on such a position that when the acellerator was kicked, the car backfired.

I wasn't looking at the exhaust at the time but it really blasted out loud.

That could have been the origin of the O2 sensor failure, right ? Question is that what else may have been damaged from that ?

I really thought I was going to set things right by replacing the TPS and the O2 Sensor, now I've got no diagnosis codes to look at and i'm getting quite desperate here ...

The thing is, being an import car, if I take it to Honda they'll waste tons of time and get nowhere with it ...

 

Where these issues your having now the same as prior to the backfire? The back fire may have done something to your catalytic converter but it would have had to have been quite the blast I think. They are built rather tough.

How is your battery, cables and connections. Clean & tight?
Did your mechanic test your ignition coil while you were replacing your plugs and wires?
Have you looked at the operation of your fast idle thermal valve?
You said you are getting a fuel pressure test kit, that's another place to check as a code 43 can stem from an ongoing fuel supply issue. this is sounding like a dejavu

 

Two cents:
When warm everyhting is fine. Does that mean engine temp or outside temp, looking/thinking ECT.

Hard start after long periods of sitting, head leaking coolant into cyl's?

 

Let's see if I can make some sense ... I'm going to try to "rebuild" the whole story with as much chronological order as I can remember.

1 - My car used to start and run fine.
However, from time to time it refused to start for a while ( like once in every 4 months or so ). I never had it checked as it didn't take long to overcome whatever trouble was causing it not to start.

This didn't become more frequent until now, there wasn't a gradual increase of this problem.

2 - This being an 18-year-old piece of auto, I gradually had replaced a few vital components in order to get a better-running car. Such parts as TA Sensor, Coolant Temperature Sensor and thermostat were replaced for new ones. Distributor, external coil and all cables involved were also replaced for new ones.

Everything was sort of "fine" until the TPS Sensor was swapped.

The electrician I had it done in had no previous experience on the matter, didn't know it had to be properly calibrated ( neither did I ) so he just swapped it and left it as close to as the original one was set.

I could read a code 7 fault from time to time but the fault light NEVER came up fixed on the pannel at this time.

However, from time to time it felt as my car wasn't performing exactly as before ( especially in gear shift timming ) so we moved the TPS back and forth trying to get it where it was before ( stupid stupid stupid ! ).

In one of those attempts that's when it backfired.

Slowly, other symptoms appeared, this hiccup sort of running being the most evident one. This happens on slow speed only, it doesn't happen when you step hard on the gas.

Well ... as far as I can remember, after that backfire incident ( my car never backfired before ), on this particular morning in May the temperature had dropped and it just didn't want to start.

I tried and tried but it just didn't want to go anywhere until all of the sudden it did start. But just before it did, it seemed as it had "coffed" out underneath the hood ... like vapor being expelled from every side of the hood along with a huge "pffffffffffffff" sound.
However, I don't remember smelling of gas that morning.

Before I did that I bought an used injection system on the eBay and had the Throttle Body swapped.

Even still ... we all know that codes 43 and 1 came up. This used to happen while driving on the highway or revving up to 3000 rpm for a while, light would come up FIXED on the dash.

Taking your advice, I had the Oxygen sensor replaced recently and I thought that was the end of it.

Nope, it really wasn't.

Over here, we're in the summer's final lane. If the weather is hot, it kind of starts so-so ... not perfect but acceptable. If the air temperature is lower, it's like "Houston we have a problem". The engine turns on forever showing little tendency of starting. At some time, the smell of gas becomes evident and starting seems even more remote than before.

By forcing it, eventually it does start but it's like in the old days, when cars worked on carburators and you sometimes forgot to pull the manual choke ... know what I mean ? Until it gets hot it just coffs and coffs like forever.
From time to time, it may even stop.

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These is the story as well as I can remember it.

Now, like I said, I bought the injection system off eBay.
Even being an used one I'm thinking of having the Air Boost Valve and Fast Idle Valves switched onto my car to see if there's any difference.

Also, is it possible that by running the car with the TPS out of setting I may have corrupted something in the electronic engine management ? Say, the ECU firmware, EACV or some other ?

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It would be easier if we had anywhere to look at, some sort of a guide light but no error codes are registered at this time which leaves us on total darkness.

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added later :

I've seen water coming out of the exhaust.
It happens especially after it starts.

When I took the car to Honda, on a "could be" basis their mechanic said I could have a bad head gasket. No tests were done ( at Honda ) to confirm that but I was told that could be the source of all this, a small leak on the gasket.

Brought it back to my mechanic, tests were made and proven otherwise, nothing lead to believe there was anything wrong with the gasket.

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? now what ?

 

Update :

Just spoke with him, car does no longer start at all.

Hasn't been able to start it in 3 days now, not even once regardless of air temperature being hot ( afternoon ) or not.

From bad to worst.

 

Last Update : IT LIVES, IT LIVES ! !! !!!

On a desperate attempt, we swapped original reference Denso spark plugs ( that were BRAND NEW, put in a few days ago ! ) for NKG Iridiums with a few miles.

It started on first attempt.

It still goes through a bit of trouble until it reaches standard operating temperature but it doesn't struggle anymore to start.

Can this mean that we're looking at a weak spark for some reason ? I had new distributor installed one year ago and performance external coil ( not original reference ), we're going to swap these for the originals to see what happens next.

Any advice ?
It still isn't quite the car it used to be until it heats up a bit ...

 

I am also thinking the ECT or the thermostat.

 

Did the mechanic check the condition of the spark plugs? They may have been fouled due to the car running rich. A faulty ECT and/or a faulty thermostat could be a cause of the problems you are having.

 

My thermostat is also brand new and it's working fine ...

I know I shouldn't ask but ... what is the ECT ? ??

edit : The NGK Iridiums I had put in about 6 moths ago, the Densos were bought last week when we started troubleshooting whatever was wrong with the car.
Now, how come it starts with an used set of sparks and doesn't with a brand new set ? ?? ???

 

Engine Coolant Temp sensor. Basically tells the computer what the engine operating temp is so it can adjust...like the choke on a carb....You mention replacing a switch but not sure which one- rad fan, green by t stat. I think the ect for yours is under the dist, multi wire..not the single wire.

 

I had that sensor replaced, it's the one by the Thermostat housing, right?

I can have it checked or re-replaced, no problem as they come cheap.

I don't think my car has the one by the radiator, I once asked Honda but they told me my car didn't have one of those.

As for relays, if you're talking about the one underneath the steering wheel, I can hear it click when I turn the key, if you mention another one then I don't know ... yet.

Speed of starter and sound are the same when it starts or doesn't start, It turns quite nicelly. My started's been reconditioned as well.

 

We are referring to this sensor. It this the one replaced?

 

I think it was the TW sensor I had replaced. Must recheck when I reach home as I'm not 100% sure. I can remember a green connector but it might belong to one of the other sensors I had switched.
That helped one hell of a lot, I didn't know there were two of them

One final help, I'm having a bit of trouble locating the ETC under the hood ... it obviously is located somewhere in the coolant circuit but where ?

Thank you

 

The ECT "sensor" should be located under the distributor. The other ECT is a switch.

(This next part is a copy and paste from another HT thread) The ECT sensor reports the coolant temperature to the ECU. The ECU uses this to find out if the engine is cold in which case it adds more fuel so the engine can warm up faster. The ECT sensors is also used to adjust spark, EGR function, open/closed loop feedback, idle speed and so on...

 

NOT the green connector. The ECT should have a white/yellow ish color (using the 86-89 and the 95 I have). Sorry for confusion, most of the time the fan switches get replaced, the fan switches have green connectors. The bottom picture should help you find it, note that the water housing in that pic is for the upper hose.

EDIT: Sorry redbull, did see your post until I posted mine.

 

My friends, you two are absolute stars, I thank you one heck of a lot.

I'll try to locate it and try to order a new one first thing tomorrow morning.

What you say makes absolute sense, let's see how close you hit the bullseye.

Will report soon, thank you !

 

this is the problem i had coolent leaked in when not running then was hard to start .... replaced head gasket and its all good now BTW thanks poor man

 

Not mine. My coolant level doesn't go down and there's this professional test ( from Wurth ) that turned out negative.

I'm going to have a look at it in a few minutes ... what if the ECT turns out to be ok ?
Where else should I turn to then ?

 

Guys ... I'm feeling like such a dork you can't imagine, I nearly feel like shooting myself out of my own dumbness ! !! !!!

My car is fixed and it only took me 5 minutes to do so.

As for the ECT sensor, I phoned my usual Honda parts dealer and he reminded me I had mine replaced last April. Its still as new as they come, the trouble wasn't there either.

Wanna know what was causing all this trouble and probably ended up causing an O2 failure as well as all this mess ?

I'll show you what it was. If you ever come across the urge to have one of these installed in your CB7s ...



... well then take my advice and save yourselves the trouble to have it ordered, picked up and professionally installed. Don't you bother. Just grab the money and throw it out the window at once.

Like my mechanic sayd, I ended up 'buying a problem' I didn't had with this piece of junk.

Just for you to laugh even more out of my misfortune, wanna know how long this coil lasted in my car ? I'll tell you, this was bought and installed in June.

Amazing, isn't it so ?

Just to end this up, out of a consciesness relief, I brought the old original Honda external coil and plugged it into its place, fired it up and it started on the first half-turn.

Not only did it start but it held itself just fine as the engine heated up, marvelously in fact.

Just to make sure, we pulled out the 'backup' fuse to clear all ECU problem reports and took it out for a drive.

First we ran it slowly, averaging 80 mph on the highway, light didn't come up neither did it heat.

On the way home, I swear you on my honor, we ran the car above 130 mph just to make absolute sure everything was perfect and it held himself like a lion.

Stopped back in the garage, plugged the clip to read error codes and the was NOTHING in it.

Good god, I'm such a happy man today ... you just would not believe ... ! !!

IT LIVES, IT LIVES !

I wanted to thank all of you who left a few lines in here trying to help me, I really was far far far from suspecting this to be the cause of this all.

Thanks guys.

 

lol.... I wasn't that far off then.

Just because it's a new part doesn't mean that it can't fail!

Nice to see that you got the issue resolved.

Cheers