'91 CRX SI running like it's on 3 cylinders..

[richmas1]

I checked distributor, wires and plugs. All in good to great condition. No fluids in cylinders. Upper head section looks fine. VERY well maintained car - garage kept.
Replaced in past year or so due to wear and tear- Distributor, spark plugs, fuel filter, fuel pump (in gas tank) and starter relay.
Was driving home from work, turned onto interstate and car started sputtering then sounded like it was only running on 3 cylinders. Pulled over, checked it out. Found no clear issues so drove it gingerly home.
Any Ideas?
Thanks for your input.
I'm only owner. Bought new in 1991. Had / maintained this baby for last 21 years.

 

[Autoteck21]

check your map sensor? and connector, if they lose contact it will run as if you have a dead cyl. and have you checked all for injectors to make sure they firing? only other thing i can think of off hand if all elts is good would be your dizzy module? how you say you turned a corner then got your symptoms sounds like it would be wiring but never know.

 

[Dual-500]

Run a compression test on it.

 

[dacheat]

update?

 

[richmas1]

Update;
check your map sensor? Done - no problems.
and connector, Done - no problems.
if they lose contact it will run as if you have a dead cyl.
and have you checked all for injectors to make sure they firing? Done - no problems.

I should have seen this coming. Just before I changed out the in-tank fuel filter, the car would "buck" every now and then when I made turns. I chalked it up to the fuel filter and sediments in the tank. It probably is a module or sensor that is getting a poor connection due to age. I probably knocked it "out of whack" with that turn onto the interstate. I will continue to investigate as time allows.....
Thanks for all the support guys.

 

[Dual-500]

I would also be tempted to run a compression test on it. You can probably borrow or rent a test gauge from a nearby auto parts store.

Sometimes there are diagnostic tools to use, sometimes the built in diagnostics will tell where the problems are - much of the time for me, it's process of elimination - the long way home....

Good luck with it.

 

[richmas1]

Final update for " running on 3 cylinders..."

Just posting this to possible help save a fellow member some aggravation;
I had the fuel pump changed out in the gas tank just prior to the engine problems.
I had installed a new fuel filter at the same time in the engine compartment, instead of running the vehicle with the old filter for a while to filter out any "crap" that may have been kicked up when doing the fuel pump in the tank.
I recently installed another clean fuel filter and replaced my spark plug wires as well (trying to cover all the bases since nothing else seemed to be wrong!).
Car started right up and has been running like a champ for the last few weeks!
Prior symptoms were; car would sputter up to speed during acceleration. Once at desired speed, car would run fine. When slowing down, car would act fine but sputter during idle and eventually stall.
Hope this helps...

 

[dacheat]

definitely helps - thanks for the update!

i actually had my fuel pump and filter replaced last month in my rex, too. the mechanic thought i was dumb, but i asked him to replace the main fuel relay, too. my plugs n' wires are less than 10k miles/1yr old, so i'm going to leave them alone.

symptoms of my fuel system probs:

• flaky start-ups (somewhere between the MFR and the fuel pump)
• what felt like occasional and random stuttering power during my roadtrip (400 miles to blow the dust off)
• increase in flaky startups
• increase in occasional and random stuttering power drops, resulting in involuntary deceleration - then it'd pick right back up again (3-4 times on this one before the final fail)
• the final fail - involuntary deceleration at highway speed, and failure to start

nothing some roadside assistance and a towtruck couldn't handle.

hope that helps others reading your thread, too. i'd always thought that fuel pumps would fail spectacularly (they work or they don't), but this one apparently felt bad about dying on a roadtrip. mechanic says "nothing wrong with your main fuel relay" and didn't want to replace it. i told him to replace it AND get me a spare one to keep in the car. just in case! ^_^