Ltd4all

I have a 1987 Accord LXI (2 door hatch back) and intermittently, usually after running for awhile, the engine will start to shudder ONLY under acceleration. The engine will Idle all day long and idles VERY smoothly, but as soon as more than 10% throttle is applied, it acts as though it's hitting a rev limiter set to 1,500 RPM.....I have noticed that if I place the car into neutral and coast, then turn the key off and back on quickly enough that the engine doesn't stop, allowing it the engine to "catch" it before a complete stall, 9 times out of 10 it temporarily "solves" the problem for a varying time between 5 minutes to more than an hour.....I have heard problems with the distributors, yet the car idles smooth...I've also heard of problems with the ignition modules and pick up, I've looked for a distributor, and it costs $300+, and does NOT come with ANY electronics, the ignition module costs around $100, and the pick up costs around another $100, so to replace all of the above, it would cost $500.....I'd hate to replace the distributor if it's unnecessary, but I don't want to start throwing parts at it......any ideas on how to diagnose or test the module or pick up? should i start with the module and pick up and save the distributor for last? Is there a list of the codes somewhere online? (there's a "computer" under the driver's seat with a LED that flashes only when the ignition is cycled, and doesn't flash any "codes", it simply lights once when the ignition is turned on......though I can't watch the LED while I'm driving, and the problem happens......

Ltd4all

I forgot to mention the engine is a 2.0 liter EFI (PGMEFI)with automatic transmission.....

poorman212

A bit lost on this one but I will give you another train of thought. Only happening after the car warms up also brings the egr system into play? The "rev limit at 1500 rpm", is that also after it warms up and in neutral or just in drive? Does it "pass through" the issue or act ok under slow accel...vac advance. Sorry I can't give an answer but may be I can help you get closer to the issue.

Ltd4all

Engine displays the symptoms in drive (D4 and D3) neutral AND reverse (and obviously in park) the "shudder" seems linear in the fact that light throttle inputs tend to make the engine rev slowly, then decelerate slowly, almost like a slow pulsation, sort of like if the ignition was connected to a sort of delay wiper switch.....full throttle makes the delay (dead spot) longer, but it doesn't allow the engine to stall, where at light throttle, it's more of a cycling ignition miss. All spark plugs are firing and in time, though I have yet to have the car display these symptoms in the driveway while I have my toolbox open. I also notice a slight unburned fuel smell when this issue starts, and the smell seems to become stronger after trying the full throttle approach...

I don't know if the module inside the distributor is vulnerable to heat (engine or electrical) or vibration, or if the ignition pick up is vulnerable to magnetic field loss, heat or vibration....I doubt the distributor itself (mechanically) is faulty....I'm wondering if there is a way to test or diagnose the ignition module and ignition pick up separately aside from systematically replacing those parts and hoping the problem doesn't come back, or get worse!

To clarify, the engine/transmission or driveline does NOT make any strange noises when this happens, it just acts like someone is turning the ignition switch on and off, and the throttle somehow controls the speed of the switching, without allowing the engine to stall EVER. I've tried putting the pedal to the floor while it happens, and the engine doesn't stall, it seems to always keeps itself from stalling. the engine doesn't backfire or pop....

poorman212

Have you downloaded a service manual, I'm sure there is/are testing prcedures in there for the dist.
Does it do this when the engine is cold?
You did bring one more thing into play "fuel smell", FPR?
Sorry, I just re-read about the ECU. Does the CEL come on at anytime while driving, if so there will be a code stored.
Again, sorry I don't have one answer, just trying to help you with figuring it out.

Ltd4all

The only code displayed is (13), but this code does NOT follow normal protocol. From what I understand based on previous conversations with Honda techs, the codes are based on "digits" separated by a pause in the flashing codes - a single flash, followed by a pause, then 5 flashes would equal a code of 1-5 or 15 The only pattern I can retrieve from the vehicle is 13 short flashes NOT separated by any pauses, and the Honda tech I spoke with a few years ago (this code has been there for years, and the PGM-FI light is almost always lit after about 20 minutes of the engine running) is designated as a "internal Honda code" and shoutumper" from the case of the PCM directly connected to the (-) terminal of the battery and the problem eventually surfaced after a reasonable amount of time with little if any changes to the conditions when the problem is experienced. I have yet to get the vehicle to "act up" while in the driveway with a chance to test anything.......and almost every time it does act up, after "rebooting" the ignition switch, the problem goes away for another length of time. If for instance, from a cold start, it takes 2 hours of mostly highway driving to give trouble, rebooting tends to delay it reoccurrance for about another hour...

I understand this is a real stumper! I have talked to a Honda Master Tech who was in the field prior to and during the time when these vehicles were commonplace. This Tech isn't some young kid right out of vocational school.....He's had his hand in these systems since day 1....He has Honda certificates for EFI training dating prior to 1986.....Before this particular system was available to consumers! this guy knows his stuff!, yet the only information he could find about that "13" code is that 1. it shouldn't exist, and 2. it should easily clear either by disconnecting the battery (I've tried leaving the battery disconnected for over 24 hours, and "shorting" the + cable to the - cable.....AND disconnecting the connector from the PCM while the battery was disconnected.....virtually eliminating ANY memory factor)

I've looked for manuals on-line, Chilton manuals (the paperback repair manuals) and actual Honda factory repair manuals the were provided to dealers at the time and up to 5 years AFTER the vehicle was in production (1987-1992). NONE of these resourses will help me figure out what this code "13" is trying to tell me...especially the way the code is "spelled"...even if the code is presented in the proper series of blinks, there is no "code 13".....

Still stumped!

Ltd4all

Coolant temperature NEVER reaches above 45% (less than half way up) and NEVER comes NEAR the range of "hot" or overheating.....I tested the accuracy of the dash gauge by temporally disconnecting the cooling fan on a hot a humid day, and letting the car idle for 30 minutes to see the reaction.......the gauge went up past 70% and began to creep into the "hot" or red area......and i plugged the fan back in and the temp stabilized back to 45%.....it's NOT overheating, but it seems to only do this after running for awhile and during that temp gauge test, the car was running at idle for about an hour total....building heat without having much as far as a cooling breeze (from moving), so I figured if it was a heat issue, that would bring the problem, and it never showed......I've tried "wiggling the ignition switch while it happens....thinking it might be a worn contact in the switch itself...no solution (the car key is the ONLY key on the keyring with a small rubber fob to help prevent this in the first place!) I never hang a "janitors keyring" from ANY of my ignition switches!....Yet, when the problem "happens", turning the engine off, then turning it right back on (without engaging the starter) solves the problem!

poorman212

I just looked at my old Chilton book and see code 13, have to be careful turning pages as it is at least 15 years old and has been through a lot.....

13=Atmospheric pressure sensor.... There are a couple of things it states to also check.

15= (though I can't directly tie this to the 87, it does show for some other years in the same gen model 88-89)-Ignition output signal. I don't think this applies at all to your year/model.

Not sure if that helps or not? I think the book is from 92, might try the ISBN of 0-8019-8255-3-Chilton Total Car Care 84-91 Accord/Prelude. I've still use this often, wire diag, vac diag, codes, ect....back to the F1 race.