garnet

1990 Integra
Symptoms
-stutters (sort of bapbapbap) at wot under 2,000rpm but only once thoroughly warmed up
-cooling fan not coming on
-getting trouble code 43
-seems to be hogging fuel (haven't measured but just from watching fuel gauge drop)

What I've tested
-power directly to fan, fan is good
-tested fan relay, relay is good
-tested coolant temp sensor, sensor is good (couldn't find actual ohm range, but it's 1.4 when cold and 0.4 when hot, or something like that, forget numbers atm)
-disconnect 02 sensor, cleared ecu, same stuttering symptoms (to check if 02 sensor is sending faulty info), so 02 is likely not the culprit
-fuses all good
-disconnected ect sensor to see if fan would come on, didn't

What I'm thinking
-code 43 is fuel supply, but more precisely means excess carbon in the exhaust. This combined with the fan not coming on had me thinking the coolant temp sensor was shot, so not telling the ecu to turn on the fan and lean the fuel, leading to the stuttering. However since it checks out I'm wondering what it could be.

Any suggestions?

Thanks.

Solster

Cooling fan switch is in the Thermostat housing and it turns on the fan.
this will be open or closed it's a switch. so cold no reading Hot (215F) 0.0ohm's

Coolant temp sensor is in the head under the distributor and tells the ECU the motor is hot or cold.
5k~7k ohm's is 32F/0C
2k~4k is 68F/20C
900~1.2k is 104F/40C
300~400 is 176F/80C This is Normal operating temp
100~300 is 248F/120C

code 43 is based off a large number of factors the most common is Distributor and the rate the injectors have to pulse to get the correct reading from the O2 Sensors.
Most common fix for code 43 is a full tune up cap, rotor, plugs and wires

I did this and later found out my fuel pump was failing as I was only get 26 PSI fuel at idle and 34 at WOT. spec is 38@ idle and 48 at WOT for a Stock LS Motor and 45 Idle 55 Wot for a GSR B18c1 swap

Any time the CEL is on the motor will eat fuel like it was free.

garnet

Thanks!

Are you thinking of a '94 or later Integra? There is no switch on my thermostat housing.

Double checked ECT sensor
20*C 2,000
100*C 400
Also forgot to mention that I disconnected ECT sensor (ecu should default to fan on if it doesn't get a reading) and the fan didn't switch on.

How did you check the fuel pressure? I have a pressure gauge but none of the adapters fit and Honda wouldn't sell me an adapter as 'it's a Honda tool'.

Thanks again.

Solster

I own a 1991 and 1992 integra and have owned a 90 and 94 integra
https://honda-tech.com/attachment.ph...1&d=1408732570

the 90 and 91 tegs have it on the back of the block under the intake. (forgot this last night when it was late)
https://honda-tech.com/attachment.ph...1&d=1408732570

the 92 and 93 tegs have it on the Tstat housing as it is in most honda's 1990 on up

connect the 2 wires from the switch and the fans should come on

I have the adapter for my fuel pressure tester but this will also work and is cheaper my set is a snap-on

http://www.ebay.com/itm/ADD-W1-Fuel-Pressure-Regulator-gauge-0-100-PSI-Liquid-Fill-chrome-oil-Gauge-100-/111390036466?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A1990%7CModel%3AIntegra&hash=item19ef5d11f2&vxp=mtr

garnet

Solster thank you for that great info! I managed to get it pulled, the fan worked when I jumped the two leads and the switch read full resistance cold or hot. I'll be interested to see if a new one fixes the stuttering problem since I would have thought these were on different circuits, although maybe the ecu goes just to 'full rich' mode when this switch is broken.

The temp gauge never got over halfway, so the coolant wasn't getting too hot, but part of the engine bay could I guess.

I'll post results tomorrow.

Also someone might find this helpful as well.
http://www.superhonda.com/forum/f5/9...switch-353440/

garnet

Okay got a new fan switch swapped in and the fan is now working, the engine light no longer goes on and there are no codes flashing.

However the engine still has the same strange stutter or miss. It only does it after being fully warmed up, at least 15 or 20 minutes of driving. Same symptoms, a tiny hesitancy at throttle tip in and bapbapbap under load under 2,000rpm, then it clears up.

How could the computer not know something is wrong?

Solster

i just had the same problem turns out my cat was melted

tamboo

tps perhaps?

The Official Honda TPS wiring and calibration thread - Honda-Tech