Question 1.

Is there a difference between the Carburated gas tank vs the EFI gas tank or is it simply the gas pump?


Question 2.

If an engine swap was done from a carburated to a EFI engine would the gas tank and fuel lines need to be changed as well?


Please respond in the same order as listed with explanations where they can be provided as not to confuse my noobish self please and thank you.

 

no

no

did i keep them in the right order for ya?

 

Perfect and thank you. Now onwards to find out why my mechanic would tell me such a thing...

 

what year and model of car?

 

how could they not be diff? There should be no return line port and no baffling in the tank. Both rather important.

 

precisely why i asked for year and model - no 88 and up USDM Civic/CRX was carbed, however 3g Civic and 1g CRX models came both ways, carbed and injected - they do have different fuel systems and swapping a fuel injected engine, which uses a pressurized fuel system, into the carb model, which isn't pressurized, does require replacing the tank, pump, lines etc. - not to mention almost all of the wiring in the car

 

My car was dual side drafts. Huge pain in the ***. I put in an injected accord engine a long time ago and now it has a B20v. Making/running a new return is easy, dealing with the lack of baffling sucks.

 

Ok so i bought the car with a EFI engine installed (ZC). I am trying to correct whatever botched up work that was done. So far I have changed ecu and harness for the engine. In regards to my fuel lines and gas tank what would I need to do now? There is a return line based on what was said above how ever I'd need to know what else needs to b done. The car is a 1990 Honda Civic Hatch Dx LHD.

One thing to note is since I have had the car I have gone through 3 brand new fuel pumps so far. What will I need to do now to get it working in proper order?

 

since the car is a 90 DX, which was originally fuel injected, not carbed, the stock fuel system is o.k. - why 3 new fuel pumps? - usually, if the fuel pump is not working, the cause is a bad main relay and not the pump

 

I am being told that it is a carb gas tank on the car but after all the work recently done on it electrically I'll find out in a few months I suppose.

3 fuel pumps were as a result of a constant plague of electrical problems since my ownership of the car. The previous owner swapped in a ZC from a DB6 Integra, on a pm7 ecu and harness. The harness kept shorting out and and breaking and in the last instance of repairing the harness and found 6 breaks in the harness I got fed up, went searching for a new harness and simply could not locate another harness sooo I got a newer harness and ecu P76 which a friend of mine with a DB6 is using to run his ZC motor as well as advised by my electrician and mechanic would be just fine to run the motor providing I got the rest of stuff to go with it namely, dizzy, intake manifold, injectors etc.

I got a main fuel relay but I am simply pissed, in shock and awe of the fact that since the repairs started in december I bought a new fuel pump, found more electrical problems than I anticipated including an opening that was the result of my constant battery drainage and now once again before I can drive the car and be on my merry way am being told I'll have to buy another fuel pump.

 

let's back up - are you in the U.S.? is the car a USDM model?

 

Not in the U.S.

Yes the car is a USDM model

 

There were carb models of a fourth gen civic just not in the US.

 

o.k. - the USDM 90 Civic hatch cars were all fuel injected, not carbed - the DX and STD (4-speed) models were Dual Point Fuel Injection (DPFI) and the Si models were Multi Point Fuel Injection (MPFI), but they were all fuel injected - for that reason the fuel tank, lines, etc. were the same in all of the USDM hatch cars - you said you changed the harness for the engine - has the wiring for the car been converted from DPFI to MPFI? - are you running an OBD0 to OBD1 ECU jumper in order to plug the OBD0 chassis harness into the OBD1 P76 ECU?

 

I believe the conversion from DPFI to MPFI was done. This the first time I am seeing someone refer to more than one harness in a car. There is only 1 harness that I am aware of that connects the ecu to the motor, dizzy, injectors etc. The term chassis harness suggests something different to me.

I feel like i'm being a pain in the butt. If i am i'm sorry about that

 

not a problem - the car has a chassis harness that plugs into the ECU and runs up through the firewall at both sides of the car and has connectors at the firewall for plugging the engine harness into - the engine harness is a separate harness that plugs into the chassis harness - it has one connector on the left side and two connectors on the right side on the DPFI harnesses - the MPFI harnesses have three connectors on the right side

this is the stock DX DPFI engine harnes:



this is the stock Si MPFI engine harness (the right side connectors are on the right side of the picture):

 

Ok I undertand everything you've explained and the pictures were really helpful.

The harness that is now in the car aka the one i bought for the p76 ecu resembles the MPFI harness. At no point however was I directed at another harness during the installation, hinted as whether one would be necessary/needed as everything on the harness had a connection for each respectable place. From ecu, through firewall straight to the motor, injectors etc.