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Since this is my first post (Been following ECTG for a long time on youtube) I’ll introduce myself in a few words.
I primarily work and tune European auto’s. Its my second job/hobby. I work as an aircraft mechanic for the Coast Guard. Its inevitable that I get requests for other imports for coworkers/friends and that sometimes puts me out of my comfort zone. This particular Honda, more so than most. The bane of my existence; late 80’s to 90’s feedback carburetors…
This 88 Accord has a hesitation right off the throttle. The rpm sags and then seems to accelerate. It also has NO useable power on light to mid throttle or in the lower RPM range. It runs smoothly, no surging, bucking or misfiring. Just no power and that slight stumble right at throttle application. If you push it to have the auto tranny downshift and you get in around 3,000 RPM, it will move reasonably well and pull smoothly and steadily to 5,000 RPM.
This problem he said has been going on for about 6-8 years. Has gotten no better or worse with time.
What the owner has said has been done:
Reman carb.
Fuel filter
Tune-up
He said one mechanic advanced the cam timing!? He said this has been reverted back to stock settings.:blink: I haven’t checked yet.
Some other things I can’t recall now. Some of these things were done 2-4 years ago with no improvement to the problem.He’s had it to a list of various mechanics. Some of them doing shady work and didn’t help the problem. Now I suppose I’m up to bat…:sick:
What I’ve done:
Traced every vacuum line and confirmed it with the under-hood chart.
*The distributor vacuum hoses were crossed
*The choke actuator vacuum hoses were not plumbed correctly
*Some hoses (Maybe 4 total) around the carb were capped off or routed to the wrong areas.
*I noticed when I hook a vacuum pump to the inside choke actuator line, it will move the choke but will not hold vacuum. However, no apparent vacuum leaks around the diaphragm (with carb cleaner sprayed on the diaphragm) Also the choke opens fully and closes with engine temperature.With these corrected, it seemed to idle a little smoother and higher. But the main problems persist.
So with this and any other questions you’ve got for me, perhaps we can get this owner happy. I know there is a lot of older Honda tech guys on this forum, so hopefully that will help. This Honda vacuum system seems overly complex to me.
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[quote=”college man” post=33149]keep us posted. 🙂 what are you going to do about the distributor?[/quote]
I’ll tell the owner I need to order him a new one tomorrow when I see him. I haven’t called my parts distributor, but I checked on Rockauto. They have one for 120 or so.
Its been a crummy weekend over here with rain. I was hoping to have time to weld floor pans in my VW Caddy… So much for that.
Talked to the owner today. He…wants me to find him a used one… *Insert bang head on brick wall emote*
To save yourself a headache.tell the owner you
can’t find a used one.its either new or nothing.:stick:
here is a link to a Honda parts sight that I just borrowed
from Eric.(thanks dude);)Well finally got the new distributor delivered and installed. Timed it. No improvement. I have confirmed the vacuum and mechanical advance are working. No one’s very happy about me convincing him to buy a new distributor and it doesn’t fix the problem.
[i]
I’m completely out of ideas now.[/i]In the meantime I did some other work on his Honda. CV axle, upper control arms/bushings (for ball joints) and replaced a incorrectly installed lower ball joint he just had replaced. Also did his valve cover gasket and checked the camshaft timing. At the very least it idles smoother and starts quicker/cold starts smoother. But the issue of the hesitation right as you take off from a stop or slowdown is still there.
I think you can rule out the ignition being the cause of the hesitation at this point so perhaps it’s time to turn back to the carburetor. If the power valve is sticking or something like that then it could also cause a hesitation. If it were at a shop they would recommend purchasing a reman carburetor. Before you go there however check for vacuum leaks at the base gasket. I’ve seen more than one occasion where this happened and caused performance issues.
The distributor did not come with a new ignitor, so I was going to try that. But I’d think if it was the ignitor you’d have some more symptoms at higher RPM and load.
The carb has already been replaced by the owner for a reman unit previously with absolutely no improvement. The power valve is not sticking and starts spraying fuel as soon as the throttle plate moves and continues to spray until WOT. No leaks around the power valve. This is if you’re referring to what I call an “accelerator pump” I’ve heard tell of some other vacuum operated “power valve” thats controlled by another solenoid. I have yet to see this item.
I’ll check for vac. leaks around the base, base heater and the manifold.
I’m not sure if you have seen my video on page 1, but the white vacuum valve I point to “chatters” when coming off the throttle. If I remove and cap the top vacuum line, the idle drops and the hesitation gets much worse. When I connect the vacuum hose, it takes a few seconds for the idle to increase and smooth out and the valve will chatter for a good 5 seconds. What does that valve do/what is it called?
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