Tour2ma

First timer here hoping this thread might hold the answer I'm looking for.

I've read threads on the PGM-FI Main creating hot start problems. My issue is somewhat different as follows...

Summer of 2010 my '94 Accord EX CPE developed a problem where in the heat of the summer it died on the road a couple minutes after a "cold" start-up. Winter 2010 the problem disappeared.

Summer 2011 it came back. This past "winter", or what passed for winter in East Texas, it never completely went away and it has gotten worse since then.

Couple details...
- when it dies, it just dies... no sputtering, it just dies.

- it only tries to restart, if ignition is switched from "Run" to "Acc" position before trying to restart (makes me think that some "relay" has to be reset).

- if try to restart without switching ignition to "Acc", it will crank, but never catch or even try to (makes me think relay in the fuel pump circuit).

- after each restart the time it will run before it dies is proportional to the time it sits between attempts, i.e., if it is switched off and then immediately back on, it dies almost immediately; switch it off and wait 10 seconds, it will run a few seconds; wait 20 and it will run longer, etc.

- depressing the accelerator part-way to 1500 rpm or so, will make it run longer, but it will still die.

- eventually, after enough attempts, it will begin to run longer and longer between shut downs;

- ultimately it will run, but the length of time it takes to get to "ultimately" is getting longer... where it was once 30 minutes or so, now it can be an hour or more.

- once it runs, it is generally good to go the rest of the day, and often the next day as well, but let it sit two or more days and it's back to square one.

- If it rains on it during one of the days it is not used, it seems more likely to have the problem.

Anyway, now I'm thinking electrical (which means I'm in trouble). In particular relays since the problem started in hot weather only and the reset needed to restart.

In particular the PGM-FI Main Relay seems to fit the bill given what it energizes. Is it a good candidate? Are there others?

Thanks in advance for any help...

History...
- I'm the original owner.
- It's a 5-spd, Accord EX Coupe (original clutch!!!).
- Just over 235,000 nearly trouble-free miles.
- Just changed plugs and air filter to eliminate them as suspects.
- Last shop maintenance was timing belt #3 (with all the trimmings).
- Excepting a regrettable time or two, all maint has been by dealer. Do have a good, local, independent shop as well now.
- Lightly used now excepting occasional road trip.

StreetsideStig

Sounds like a bona fide Main Relay issue to me. Pull it out, take the cover off, and look at the solder joints. If they're cooked, like in the picture, you'll need to replace the relay or resolder the joints. Keep us updated.

brakedrum

Could be Main Relay but if it signals that pump to prime and get going at first start on a hot day, then its probably not bad. My nearly 20 year old Main Relay board looks just like the one in the picture. Same brown rosin soldering flux and everything, and it still functions perfectly.

I have a 93 Accord EX 5SP which I am original owner. My car started cutting off randomly about a month ago and I eventually traced the problem to insufficient or erratic spark from the distributor. If you know how to check for spark in various spots, let your car idle one day, perhaps rev the engine a few times too. Eventually it will cut off like its been doing. When it does it, let the key stay exactly where it is and then check the spark from the distributor. If you have the right kind of meter to measure it the weak spark will be obvious, but even lacking a meter sometimes the weak spark will reveal itself visually. Holding the coil wire near the engine and getting my buddy to crank the engine in brief bursts revealed a spark that was rather orange-- pulsing to blue, instead of the good white spark that should have been the case. I knew I had the problem isolated right then.

I dismantled the distributor and discovered that he Ignitor (Ignition Module) was out of spec and no longer able to deliver. For me, this was a situation of my own making. I fried the Ignitor doing a little hot rod acceleration one night. My car cut off immediately after I did that, and cut off randomly for days until I fixed it. Note that the the Ignition Module has long been a weak link in the ignition systems of older Accords. Perhaps the newer ones, too. I suspect it has helped sell a lot of Main Relays.

Tour2ma

Thanks for the replies...

A couple weeks ago I started chasing down the problem starting with the distributor based upon replies to my same OP on another Honda site. The other site focused upon the increased likelihood of the problem after wet weather.

Pulled the Distributor Cap and while I found no cracks, I noted that the contact points were well-worn. Threw $11 to O'Reilly for a new Hitachi Import replacement.

The problem only appeared once since... again after rain. I've since replaced the rotor as well (it too was "well-worn") with an $8 Hitachi.

Should the problem recur my next stop may be the ignitor... but after a little checking.

Thanks again... I'll keep y'all posted...

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SIDE NOTE: Didn't mention this in the OP because I didn't want to confuse the issue, but I was also getting a check engine light under acceleration at around 2500 rpm. The code readout was 21-VTEC solenoid. Since I replaced the Distributor Cap the Check engine has not come on. So the wear was apparently sufficient to cause enough mis-timing of the spark to trigger the warning.

holmesnmanny

They got these for 30 bucks at rockauto.

Tour2ma

The Relay or the Ignitor?

======================= UPDATE ===========================

Hellacious rainstorm came through here nite before last... sideways rain... small hail... the works.

The ol' Honda with the new distributor cap and rotor cranked up and ran without issue yesterday.

Not quite ready to declare victory.... but am damn close to it...

Thanks again...

holmesnmanny

The main relay. They come up with new and creative ways to rename it but if you look in all of the "electrical" tabs, you will find them cheap. Don't forget to search for a "rock auto coupon code" before you buy.

Tour2ma

Overdue final note...
Problem came back couple months ago and got to point where car would not stay running at all.

Had towed to local shop recommended by local auto parts manager (and fellow Honda lover).

Final diagnosis was fried PCM Main board due to ... you guessed it... poor solder connections.

Found used one on ebay for $50 and car is reliable again...