DeadxBunny

I have an '88 CRX DX with a B18A1 swap and Integra LS transmission. I was autocrossing with it yesterday when I experienced a complete lack of response from the gas pedal after making a sharp turn. I was at the very beginning of the course, making the first sharp left turn while switching to 2nd gear when it happened. I pressed all the way down on the gas pedal, but the engine wouldn't rev. I let off the gas and pressed on it again several times, but no response. Even when I came to a complete stop, pressing the gas still would not prompt a response from the engine. The engine was still running around normal idle speed, it didn't stall or shut off. The check engine light did not come on. So, I got pushed off the course, parked it, turned off the engine, and then turned it back on. And magically it's back to normal. The engine responds to my pressing on the gas and seems fine. So, I got back on the course to try again and the same thing happened on the same turn. I coasted off course and once I came to a complete stop, I was able to get a response from the engine again, this time without turning the car off and back on. I was able to drive the car home from the autox without any issues. I haven't been able to recreate the problem since then.

It almost seems like it was fuel starvation, but I had over 3/4 tank of gas so that doesn't sound right. Could it be the fuel pump or maybe a sensor that some how got switched off when I took a hard turn? I'm not even sure where to start looking...

I am also getting some bluish, oil smelling smoke out of the car as well as a bit of sluggishness from the engine at regular driving speeds. The smoke is not heavy and happens when I'm accelerating at normal driving speeds. When I first got the car last year, it was very responsive at all speeds. But now there seems to be a lag in response and the response isn't as "enthusiastic" as it was before haha. I don't know if all this is related to the autox incident but I thought I'd mention it anyway.

A few weeks ago, when I first noticed the blue smoke, I did a compression test on the engine and all of the cylinders gave results within the normal range. Three of them were very close and one was a bit off, but still within the normal range. I have also tried Seafoam in the gas tank to clean the injectors, but haven't noticed any difference in the smoke or engine performance since then.

Any ideas?

Kusai.Nihonjin.Desu

Also noticed black smoke as you were going up the slalom on your first run. But looks like you are running the stock ECU (PR4). Just to add more info.

DeadxBunny

anyone have any ideas?

Relic1

wouldn't rev = bogs like it has no power or simply does nothing?

my first check would be a wiring problem to the MAP, TPS, or both.... loosing the reference ground to those sensors would do something like that... also check the thermostat ground. (OBD0 is at the thermostat right?)
either way, check all electrical connections to those two sensors.

another note, I've seen distributors on their way out cause something similar, but it usually causes a slight idle instability at the same time.

JBrettHowell

Main relay needs resoldering? I had a similar experience before the car wouldn't start...narrowed the problem down to the relay and resoldered the connections.

Relic1

doubt it's the main relay. When it goes bad the engine dies immediately or the pump doesn't run... he said it idled fine, simply would not climb revs. no pump would cause the car to die(after a few seconds), even at idle.

thaonepointsixdb

-Pcv clogged
-oil pan loose
worst case
- valve seals are shot

thaonepointsixdb

hes right... pumps dont slowly go out.

2fast4u831

the engine could have let go or it's the head gasket.. did the oil pressure light come on?

blkb18

I agree, sounds like a wire is shorting or going open (most likely shorting) somewhere and only a real aggressive turn is enough to cause it. Recheck all wiring, especially ones involved with the engine swap. Good luck.

Stinkycheezmonky

X3. I'd check the TPS first, since it seems to be directly related to the gas pedal. Alternatively, any chance something is physically wrong with part of the throttle cable? I can't see how that would be intermittent really, but I had one snap in my old VW and the symptoms were very similar to what you describe...except it never came back

oinojo

i would say check your PCV valve. I used to have the same problems before i replaced my PCV valve. I also run an inline filter (compressor water separator) to help with the oil consumption i have during autocross.

Kusai.Nihonjin.Desu

Haven't been able to replicate the problem...I don't think she stated that she recently had some gas tank work done as well. And, it threw a code 10 recently.

JBrettHowell

FWIW, this is not always true. I had several instances of my motor dropping revs while on course, but once I backed off the car seemed to come back to life. Eventually the car would not start, turned out to be a main relay in need of re-soldering, and the issue never manifested again. His symptoms reminded me of my exact experience with a slowly failing main relay so I mentioned the possibility.

DeadxBunny

Ack! Haven't check the site in a while so I'm just getting around to reading these responses...

Wouldn't rev as in it just didn't do anything. Like someone just disconnected the gas pedal. It wasn't all of a sudden though. I shifted to second and got a response at first, but then it quickly faded to nothing. I will definitely check out the distributor and wiring and grounds to the MAP, TPS and thermostat. Thanks

No, the oil pressure light never came on.

I don't think there's anything wrong with the throttle cable. Right after restarting the engine I was able to drive the car again normally. I'm also able to drive the car around in normal driving conditions without any problems. But, it's worth taking a look at just to make sure.


Thanks. Yeah, I was experiencing a gas leak so I had the gas tank as well as a gasket going into the tank and some tubing from the gas line replaced by a shop. The gas leak seems like it's fixed now though - no dripping anywhere and no smells. As for the Code 10, I it a few days after the autox so I checked out the IAT sensor. All connections were solid, all the wiring was continuous and unworn, and the resistance across the sensor was within normal range so I just reset the ECU. The check engine light hasn't come back on since so I guess it was a false alarm? Or could there be something funny going on with my ECU?

I've also tried to recreate the problem in a local empty parking lot by accelerating hard, making lots of quick sharp turns, stopping hard, etc, but was unsuccessful. So, I'm not sure how I'm going to be able to tell when/if the problem is resolved. But, thanks everyone for all the suggestions! I will check all these things out and post back what I find.

thaonepointsixdb

deleted by me

DeadxBunny

Finally had some time to check a few things: the TPS, PCV valve and MAP sensor. The TPS checked out good - no loose or broken connections and all the voltage readings checked out when I followed the troubleshooting flowchart in my manual. The PCV valve I'm not sure about. I think I'm supposed to get a clicking sound from it when I pinch the tube going to it with a wrench. But I don't get any clicking so I'm just going to replace the valve. The MAP sensor has me confused... I checked the voltage across yellow/red terminal and the green/white terminal (see pic) and it was 4.95V (the manual says it's supposed to be 5V) so that sounds good. But then I checked the voltage across the green/white and white terminals and only got 4.17V when it's also supposed to be 5V.



So, I checked the voltage coming out of the ECU to the white wire and that's also 4.17V.



So... my question is: is 4.17V close enough to 5V for the sensor to work correctly or should I start replacing some wiring?

Relic1

I'm guessing you have the OBD0 wiring from the car...
you should have three wires at the MAP
white - signal
Green/white - gnd
yellow/red - 5V

4.95 is close enough to 5V.
4.17 is the reading of the MAP sensor, I'm assuming this is with the car not running.
which (to me) sounds a little off for your altitude...
this points to a bad MAP sensor not a wiring problem. (since the ECU pin shows the same voltage as the sensor)