Bizzare power cut/bogging

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error2k

New Member
Car: 91 hatch with a Z6 and OBD 1 swapped in, new distributer, fuel filter, and O2 sensor,cam and ignition timing was recently set, no CEL's. Also has O2 meter installed and fuel pump controlled by a toggle switch (long story).

Problem: When I first start it and drive it around town, it's just fine. If I were to take off down a highway and hold it at a constant speed, it will be fine for a mile or so, and then almost like someone flipping a switch, the O2 meter will go super lean and the engine will start to bog down and chug terribly and not want to rev past 3k. If I were shut off the engine for only a few seconds and then re-start it, it will act like nothing ever happened until I go a few more miles at a constant (higher) load (as in on a highway) and then do it again. Another (and quicker way) to induce this is to do a wide open run through the gears. While I'm going wide open and shifting it will be proforming just fine, but as soon as I take my foot out of it, it will be super lean and bogging down again, requiring a re-start. Because of the suddenness of it, I would tend to think that it might be some sort of sensor or something electrical, but there are no CEL's. Another thought that crossed my mind is that the fuel pump is on the way out....but then wouldn't it be doing the "bog mode" almost at random instead of after the engine being under load? Any ideas?
 
If your car is suddenly loosing alot of fuel pressure it could definetly bog down and not want to get up and go. I would definetly take care of that problem before you can chase down another one.
 
Mine does that when it's really really cold. My thought is the injectors. Either they're sticking or they just suck. But yeah, try those. That should be in your upgrade roadmap somewhere anyway. And, when you have an injector error, it will only rev to 3k. Though that *should* trigger a CEL. Chipped ECU??
 
sounds like your fuel pump is going or maybe your fuel filter but i could be wrong
 
UPDATE *insert Unsolved Mysteries theme*

Shortly after this post I installed a fuel pressure test gauge and did some runs with the car. Following the FSM, the entire fuel system checked out ok. During the tests it finally threw me a CEL, and it flashed me a code 43...fuel delivery system. According to the FSM, code 43 usually means the O2 sensor. I reset the computer trouble codes and did some more runs, and now the only code it will throw me is a code 1, which is the O2 sensor. I've checked, double checked, and triple checked the wiring on that sensor. The signal wire is going to the right place and isn't grounding out, the sensor ground wire is properly sent back to the ECU's sensor ground pin (I want to say pin D22 off the top of my head, don't quote me on that). One of the guys from a local shop suggested disconnecting the O2 sensor and seeing what happens. It basically resulted in how its acting right now, but exaggerated. It would run fine just to putt around with almost no load on the engine, but as soon as I put any sort of load on it, it would go into the dreaded "bog mode". The heater control wires were even checked and they were ok. I'm about 5 minutes from soldering everything back up again (everything was soldered up before this all began). Seeing as how turbocharging/running Crome was in the scope of this project in the first place, would skipping ahead and running Crome to disable the O2 sensor solve this problem? Any thoughts on what it might be? (note, that O2 sensor is brand new)
 
is it possible you bought an o2 sensor for the wrong OBD type? also, you wouldnt want to run without an o2 unless you like inconsistant amounts of power on partial throttle and a decrease in gas milage.
 
It was an AC-Delco universal 4 wire that was listed for a 94 Civic EX (obd-1 d16z6). I can double check the part number and possibly order another as a warranty exchange when I go to work today (work at a parts store). *edit* I only ran without the O2 sensor on the advice of a mechanic just to see what would happen as a diagnostic test. What I suggested with Crome would totally disable the O2 sensor, and judging by the many posted results of the forced induction and standalone, it would run just fine.
 
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huh the problem could be your o2 sensor but from experience it's probaly the fact that it's a ricer but what do i know.
 
update: Ive replaced the fuel injector wiring (very questionable MPFI swap was done) and replaced the 02 sensor...and it still does it. Out of desperation I threw a multimeter on the TPS and MAP sensor to see if they would tell me anything when it decides to bog down, and they both checked out ok and didn't fluctuate at all. Considering the previous owner had an AFC installed, what are some common problems that have arose from bad SAFC installations? Also, after the wiring was replaced there are no more CEL's or trouble codes being thrown, but still bogs after a constant highway cruise or after a WOT run. As usual, this bogging/leaning out is solved by turning the engine off and on. For shits and giggles the P28 was swapped out and found to be ok. Tonight I'll probably watch the cylinder and crank signals, and watch the injectors again to try and narrow things down. Other than that, I'm starting to get clueless.:ph34r:
 
what size injectors are installed now? they should be like 240cc or something stock size, and that's what your stock ecu is configured for. or, can you replicate the bog while data logging or something? check your timing?
 
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Right now it's running stock OBD1 240cc injectors, their resistance is 12.6-12.5 across the board, and the timing is spot on (cam and ignition). As for data logging....the best I can do is to run a digital multimeter to w/e sensor I'm interested in. Actually speak of the devil, I was wondering what the best way to moniter injector function with a DMM would be.

Interesting thing that I noticed today is that while idle and partial throttle act like crap when its doing its bog-down routine.....it can still go WOT like nothing is wrong.
 
im probably wrong but ive had a similar problem on my 91 hatch with a d15b7 to where i can cruise fine and all of the sudden it goes into super bog and im scrwed unless i do like you and restart it. i found that by retarding my distributor all the way it fixed my problem just fine and i havent dealt with it since.
 
is your IACV functioning? I got some weird ass conditions when mine wasnt hooked up.

I mean, i'm running out of ideas for ya. i'm sure it's prolly hooked up cuz you've checked your sensors alot...but meh
 
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Suppose there was an exhaust leak infront of the oxygen sensor, say the exhaust manifold was missing a nut or two. This would send a false lean signal to the ECU and create a rich condition. It would seem to me that sooner or later the ECU wouldn't want to trim the fuel anymore to adjust for the leak....what do you suppose it's response would be? Possibly what I'm experiancing?
 
idk do you have an exhaust leak? lol

you'd most likely see or smell it..
 
I do know that a few nuts are missing from the manifold, but since I never smelled or heard any leak it wasn't on my priority list. Right now the car is sitting in a shop so I can't exactly run right out and try it. On that subject...all the sensors checked out ok, injector flow, pump pressure and current draw, pressure regulator function, and all wiring were found to be ok so far.
 
UPDATE: The problem has been fixed for good. Turns out the injectors that were installed weren't 240cc's, most likely they were 180cc's from some OBD2 application (Y7 probably).
 
wow. good shit. I HAVE THE EXACT SAME PROBLEM right now. obd0 b16 though. bogs down and real crappy ignition at cruising speads alot of times, and especially on partial decel. mostly pronounced at higher rps(like 70+ on highway), it's very noticeable. it only does it some of the time, but it's definitely enough to be annoying/concerning. i made a post in the hybrid section about it, and i think people think i'm crazy.
i cleaned the traps,etc.. on the fuel injectors, and put everything back together, and it's still doing it. i was, like you, thinking maybe pressure/clogging was to blame. but now after i see this, i might just start replacing injectors. even though i have the stock injectors on my motor, it's right on symptoms with what you had. thanks for the info!
 
for anyone having the bog and who still has an orig. cat converter on i suggest replacing it; had the worst bogs ever in my 89CRXSi with 230kmi on the orig. cat converter (had done new muffler but not catback, sigh).

car would be fine up/down country hilly road (hwy61N towards 52N for anyone in MN). then bog would hit like a towtruck was pulling me backwards at 70 and i'd lose power and speed didn't matter how hard i tried to floor it; pull over let it sit, seemed 'fine' for a while then would do it again.

ended up catalyst had shattered and was blocking exhaust on occasion. pulled it and there was rock-hard baked sillyputty-looking stuff in there along with busted catalyst. we think the baked stuff might have been fuel additives/detergents? but hell who knows. it was scary lookin.

after replacing the cat i couldn't believe how much power i'd been losing; it had never felt so punchy. pulled a steep-ass hill by my house goin 25 in 3rd that i had gotten in the habit of pulling in 2nd at 15. didn't even feel like i needed the gas pedal xcept to keep the car from stalling. crazy. anyway. i just never woulda thought there was all that crap building up in there. 230k miles does a lot to a car though :)

ps the 89CRXSi had been a stock daily driver for 15 years getting 40mpg, god i love hondas.
 
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