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1997 civic dx hard start/very rich/backfiring/runs rough
So I’ve searched and searched and can’t figure it out!! 1997 civic dx runs very rich hard to start oncecstarted runs like crap. Sputters dies sometimes puffs smoke through intake.
no codes purchased car with this issue previous owner hit it with the parts dart new fuel pump, new iat new tps new fuel filter new injectors rebuilt dizzy new tps new iacv o2s coolant temp senors new ecu etc etc only thing i seen not replaced was the map because it’s not screwed onto tb it’s riveted. I’ve replaced plugs, brand new dizzy tried a different ecu, tried Hondata s300 checked timing, compression valve adjustment.
car will start and idel if i unplug ect sensor but dies when givin throttle. Once to temp it’s hard to keep running period I’m at a loss any help appreciated
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
Originally Posted by Justind16y7
So I’ve searched and searched and can’t figure it out!! 1997 civic dx runs very rich hard to start oncecstarted runs like crap. Sputters dies sometimes puffs smoke through intake.
no codes purchased car with this issue previous owner hit it with the parts dart new fuel pump, new iat new tps new fuel filter new injectors rebuilt dizzy new tps new iacv o2s coolant temp senors new ecu etc etc only thing i seen not replaced was the map because it’s not screwed onto tb it’s riveted. I’ve replaced plugs, brand new dizzy tried a different ecu, tried Hondata s300 checked timing, compression valve adjustment.
car will start and idel if i unplug ect sensor but dies when givin throttle. Once to temp it’s hard to keep running period I’m at a loss any help appreciated
The MAP sensor is screwed to the throttle body... the TPS is riveted to the throttle body... so you have NOT swapped the TPS based on this information, you have replaced the MAP sensor.
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
The map is labeled map. Tps on back side towards firewall on tb! When i say I’ve changed everything i have also it has new dizzy, and I’ve ohms/ voltage checked. I did notice that the tach was bouncing from 1200rpm -3000rpm and the car it’s self was not chasing idle only thing i having replaced is crank sensor
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
If you indeed swapped out the TPS you will need to calibrate the TPS sensor with a voltmeter. You cannot just take the old one out and put a new one on. And if it's an original TPS it will be attached with rivets! this takes a little skill to remove, then you can replace it with 2 m8 bolts.
Have you checked and confirmed the mech timing is correct? Did you physically look to see if the timing belt has moved from TDC?
Always remember when you have a bad sensor especially a major sensor like MAP or TPS you will throw a code for the sensor.
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
Zero vac leaks, tps has been set, injectors are brand new oem Honda, and I’ve tested them on my other civic. Timing is spot on, I’m kinda starting to lean towards a crank sensor the way the rpm signal is acting
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
The Crank Position Sensor (CKP) is found inside the distributor... the Crank Fluctuation Sensor (CKF) is found on the front of the engine at the crankshaft, but this sensor would be ignored when using the Hondata S300 system, so if the performance of the engine doesn't change when switching from an OBD-2 ECU to the OBD-1 ECU (which has Hondata installed in it... or not), then the CKF sensor is NOT your problem.
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
Originally Posted by Justind16y7
So I’ve searched and searched and can’t figure it out!! 1997 civic dx runs very rich hard to start oncecstarted runs like crap. Sputters dies sometimes puffs smoke through intake.
no codes purchased car with this issue previous owner hit it with the parts dart new fuel pump, new iat new tps new fuel filter new injectors rebuilt dizzy new tps new iacv o2s coolant temp senors new ecu etc etc only thing i seen not replaced was the map because it’s not screwed onto tb it’s riveted. I’ve replaced plugs, brand new dizzy tried a different ecu, tried Hondata s300 checked timing, compression valve adjustment.
car will start and idel if i unplug ect sensor but dies when givin throttle. Once to temp it’s hard to keep running period I’m at a loss any help appreciated
Plug wires? are they good? are they in the right order?
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
Compression test where within 3% of each cylinder and about 90% from brand new
yes the ect is brand new denso. And have swapped it just to make sure
spark plugs, plug wires, cap and rotor aswell as dizzy are all brand new
when you unplug the ect it’s goes up to 1800 rpm while cold and the rpm gauge goes up and down, but the engine sits at 1800rpm. The only stored codes are from
ect circuit low
ect circuit high
map sensor
upstream o2
these are stored because i was plugging them in and out. Every sensor is brand new including throttle body fuel pump fuel filter.
only thing unchanged is the fuel pressure regulator. I tested it though. It’s just got the injectors maxed out while running so it’s very rich also just made a new engine harness and does same thing st The are the stored codes that i turned on videos are of it running while ect Is unplugged
Re: 1997 civic dx hard start/very rich/backfiring/runs rough
Zero codes after cleared.I’ve back traced everything. Redone call grounds added grounds, cleaned fuse panel under hood looked for corrosion etc. i do have a question? Does this car have a theft system? I’ve noticed i can’t manually push down on the door locks, i must use the car to lock the car. And it kinda acts like there maybe some sort of anti theft system?
1997 civic dx hard start/very rich/backfiring/runs rough
