I have a 95 Civic EX 4-door/5 speed w/ D16Z6 that was parked for about 6 years. I cleaned out the gas tank and got things running quite well for about 5500 miles in the last 45 days. This episode has occurred twice so far, once about 2000 miles ago, which magically 'fixed itself' after playing with the car enough.

Background on the car - it was owned by a series of wanna-be car hackers. Its most epic hack is the toggle+pushbutton start (ignition switch failed at some point) and what appears to be two separate alarm systems hacked into the harness. I'm working on cleaning this mess up.

Heres the weird crap the car is doing:

A> idles like a champ
B> no power
C> misfires/backfires under load
D> sometimes just quits running for 1-3 seconds. It will return to idle without a problem though. I've had it do a perfectly timed cycle of 1 second on/1 second off. Very weird. Almost like a circuit breaker.
E> NO CEL

Things I do know:

A> it seems to have a nice solid spark, at least at idle.
B> it runs better with the fuel pressure regulator vacuum line disconnected
C> plenty of fuel pressure/volume from the pump. The outlet on the FPR *spews* gas during the prime cycle
D> doesn't magically run better (or worse) with the O2 sensor disconnected

I just can't figure it out. I thought it was bad gas, checked the tank/strainer and things looked fine, and since this started I've gone through a couple tanks without a change.

Hoping maybe its really clogged injectors, I've put a whole bottle of seafoam in 3/4 of a tank. Hopefully this cleans things out.

Any advice? I kinda wish the thing would just break so I would have a clue of WTF is going on.

I'd also like to thank the EPA for insisting on having all these sensors and sillyness - but there's absolutely zero monitoring (on any car I've ever seen) for the fuel pressure.

Any advice appreciated!

 

The first things to consider are the plugs, wires, cap, rotor, fuel filter, and ignition timing. (and the clogged injectors you mentioned)

 

Plugs are the NGK's spec'd by the sticker on the timing cover, gapped at .038, with 5k miles on them. They look normal - that was also 350 miles ago (I drove 350 miles last night..) - I can check tomorrow - its dark out now (and nowhere to work)

Replaced the rotor and cap yesterday. Brighter spark, no real change in performance. Fuel filter is newish, and appears to have enough flow (the gas coming out of the regulator's return comes out like a firehose, with 0 vacuum). Wireset is new from the last incident (no change then, they're lifetime warranty - I could get them replaced).

I threw the seafoam in earlier today, drove it around half an hour then parked it, letting it work-its-way-in now. I'm about to go give it another drive, hopefully something will change.

 

Have you checked the ignition timing with a timing gun?

 

Best way to check fuel pressure is to get a fuel pressure gauge and connect it to the port on the top of the fuel filter banjo bolt.

the line running from the filter to the fuel rail should have a bolt that looks like a large bolt with a small bolt in the top of it the small bolt is for connecting a fuel pressure guage.

fuel pressure should be about 38 PSI with vac and 48 PSI Without Vac to the FPR.

if your getting to much flow out of the FPR then you will not have enuff for the injectors

the test to see if the FPR is stuck open is to crimp the return fuel line from the FPR with a pair of needle nose pliers and see if the car runs better if it does you may need a new FPR.


also each of the injectors has a Micro screen filter in the end of them and can clog very EZ.
it may sound like thay won't get cloged cuz there aflter the fuel filter but the micro fine parts your main filerdosn't get end up in the injector filters.

the filters are cheap and most Napa auto parts stores carry them.

had to do this on my 95 Del sol when i first got it as the tank was so full of rust the fuel was Red.

to replace then use a screw and tread it in to the top of the filter basket and pull it out
to install hold the injector in your hand a tap the new one in with a small soft face hammer




Above pic belongs to turbo18 and was found by Google image search

 

Did a test drive last night - after a few seconds it was consistently missing on one cylinder (except at idle) but no backfires and no "sputter". Still gutless, but at least I know what to expect.

Exhaust "smell" doesn't seem overly rich, fuel economy is ok, and it doesn't sound like it has a weak cylinder, so I'm thinking its most likely a clogged injector screen - I should have a chance to check it out in a few hours.

Luckily I have access to basic hand tools. Just no fuel pressure gauge. I'll check what I can with my eye today, and take it from there...

Thanks!

 

Great news - took the fuel rail apart today, discovered the dirtiest/gummiest injectors I've ever seen (the tips, except for for the actual tiny nozzle/tip were covered in black goo), and clogged up injector screens (couldn't even push air through them).

Got an idea - went to the closest parts store and got a spray can of B12 carb/throttle body cleaner and proceeded to clean the screens and injector tips.

It now runs like a champ. I'm still getting trash from the gas tank (the tank-side of the fuel filter is always full of red gas) so my plan is purchase a new (as in new) tank, new (cheapo from ebay, and a spare) pump, clean the fuel lines, and hope that cures the problem

I sure like this car. It looks like crap, but it runs great.

 

Still have one weird issue:

I seem to have one problem - random power dropouts that last 1-3 seconds. These usually happen on 1-2 shifts (especially when accelerating hard) or just randomly when cruising in 5th. Seems to be far worse after I've used about 4.5 gallons (from a fillup) of fuel. I assume its fuel related, but it comes/goes almost instantly. This issue has never caused backfires or other signs of lean fuel - I have power one second, then I don't, then I do again. It usually stops doing it if I back out of the throttle for a couple seconds then slowly ease back into it (or it will start the 1-second-on/1-second-off cycle as I ease back onto the gas...)

If I clutch the car, it always 'catches' for idle when the problem is occuring. Idle is always fine.

I have reflowed the solder on the main/fuel relay already. Doesn't eliminate the possibility of broken/weak components, but the most common failure has been checked.

Anyone heard of this problem before?

 

 

I don't have a honda yet, picking it up this weekend, but in my old mustang, it would do something similar and it was the fuel pump going out...because eventually it would just die all the time. it would kind of struggle randomly (kinda like what you're describing) Since you plan on getting a new pump and tank, that could solve the problems. Also like ron said, i'd check the timing just to be sure... Im pretty sure you can rent timing guns from the auto parts stores you basically have to purchase it, but if you return it then you get all your money back. But you should buy one anyway because they're nice to have.