eepr5

went out for lunch and noticed my car sounded a bit more "rumbly" than usual, and idle was dropping to almost zero and picking up again. get on the road, gave it gas and it would feel like there was no power, then it would just kick in and out at like 4K. felt like major hesitation. Had me worried, but figured it was just cold and hesitating cause of the changing weather.

ran through a car wash to get some of the road grime off from my thankgiving roadtrip (during which it ran fine, though I've noticed the occasional idle drop for a while). Drove away and had major hesitation, which turned to engine bucking and dying. I managed to nurse it off the road and to a gas station 50' away. Turned er off and let her sit for a minute or two. Popped the hood to check if anything looked really wrong. Checked the dipstick and oil level looked ok. Restarted the engine, everything sounded ok, idled well, no dipping. I let it idle for a few minutes, revved it slighly at the trottle body, no noticable stall attempts.

So, now thoroughly concerned, I drove her the 1/2 mile down the road to Advance Auto. No noticable hesitation or anything, but i kept it at or below 4K. Had somebody there do an obd scan for me, since there was a cel. Result was a code P1129 "Manufacturer Control Fuel Air Metering" according to the printout. I figured it was probably the MAP.

Drove back to work and everything seemed to be running like normal, no hesitation or stalling.

looked in the service manual, it said the code was for too high pressure at the map. It said the check was to run the engine at 3K till the fan came on, then check the map pressure.

now, I've read about the "map whack" and cleaning the throttle body. I picked up a can of throttle body cleaner and am planning to give that a go in a bit. Then I'll disconnect the batt & clear the ECU, hopefully making the CEL go away.

Think this will aleviate the problem? Anything else i should try and check?

any help / suggestions would be appreciated.

thanks,
John

xviper

This could be simply an intermittent problem. Go with "freshening up" the MAP wiring harness connections by unclipping it and wiggling it back on. You might even try the home made zip tie hold down thing to keep the connections solid. The final approach is to get a new MAP sensor, in which case, you may as well get the new Honda securing system.
https://www.s2ki.com/forums/index.php?showtopic=253242

ps. There is no need to disconnect the batter to reset the ECU. That's doing it the hard way and you will need to enter the radio code. Pulling out the "BACK UP" fuse for 1/2 a minute will do the same thing without any of the side effects.

eepr5

ok, I'll try that too.

didn't think about the fuse. don't have OEM radio so i don't think about the pulling the battery issue, since my alpine doesn't seem to forget stuff on a disconnect.

eepr5

well, wasn't able to try anything while at work, but I reset the ecu before leaving. it barely idled, and died whenever I let off the gas. drive home was interesting and involved restarting the engine at just about every stop. luckily home was close.

got home, decided to do simplest thing first. found a mallet w/ a rubber handle, discionnected the map and whacked it lightly a good dozen times. reconnected, reset ecu, started car. it idled wonderfully, never dropped below 4 bars. let it settle for a few minuted then drove around the block, getting up to about 5K. felt nice and smooth and dropped right back to 4-6 bars and never dipped. I was very happy.

went and grabbed some zipties to strap the plug in. very simple, 3 ties to make a tight loop AROUND the throttle body behind the map, and one around the map and plug, threaded through the big loop to hold it in place. looks a bit funny, and i'll have to keep an eye on how the ties react to the temps, but otherwise quick and functional.

made a slightly longer/faster run to the grocery store, everyting continued to work good, so I think I'm in the clear. The real test though will be if it continures to do good in the morning.

xviper

You can always get the thing that Honda invented for this.

eepr5

i know, and I probably will at some point. I just wanted to do a quick solution since the nearest dealer is an hour away.

eepr5

ok, after about 2 weeks of the map whack appearing to be a solution (though I was having to do it every couple days or on major temp changes) my car has been running ok.....

then I drove to tyson's sunday to see some friends (~80miles). The trip up was fine, but the drive back all the problems came back. Had to pull over and whack the map a couple times, after the first minute or so it would start acting up again. Absolutely no power. Stumbling/stuttering at anything but the most gradual throttle change. Stumbling/dying at idle. The exhaust was noticably louder, alot more popping and sputtering (not really backfires, but more like a bunch of muffled firecrackers going off without the crack, only the pop) To me it sounded alot like an old muscle car idling poorly with big lumpy cams.

NO CEL YET!

anyway, i managed it nurse it home carefully. Brought it on base this morning (I think it was even worse than last night) to take it to the autoshop and check some stuff, but I didn't know they're closed mondays. I left it parked there to wait till tomorrow. I'm getting a rental to drive around in for now.

I just placed an order for some parts through hondaautomotiveparts.com, new MAP, new valve cover gasket, new retainers, new collets (32 ugh). Should be here in a few days, paying for overnight, but not everything in stock. Parts guy said probably wednesday.

I'm hoping its just something like the MAP being really dead or dying, but I ordered the retainers as a precaution. I have accidentally overrevved it ONCE about 10K miles ago. I plan to do a valve adjustment/inspection since I've never done one and have no clue when it was done last. If the retainers are f'd up, its easier to just have them on hand.

I've also seen the threads regarding the fuel injectors, figure those will be the next step in diagnosis. Haven't got any cels yet though so I'm guessing they aren't the problem. And I can't run the car long enough to get a bottle of injector cleaner through them. Plus i'd rather rule out the other potential major mechanical failure (valves) first.

comments?