Hello,
I have an 89 si and this is what it currently has... it was a 1.6l and the motor took a **** so I went to a shop called RSPEC it is a well known tuner shop in SoCal. They pulled the motor and put in a d15b vtec and attached to that is a ram air intake,headers down to test pipe and full axle back exhaust system. Every thing has been going fine until about two weeks ago I left the mountains and took a trip to see my dad in corona. I came back and parked it. The next day I started it and took off to go to work, I was leaving and my car started to sputter really bad so I thought I was running out of fuel because my gas level does not work and it’s always on full, so I got to the gas station and put 20$$ in and the pump clicked off at 17$$ so I thought it was weird for it to be acting as if I had no gas when I actually did. I was thinking it’s probably the fuel pump go out so I ordered it and did the job. After the job was done I did a test run and it was doing fine so I parked it. Next morning I went to leave for work and the same issue happened again,sputtering and lack of power and wanted to die so I took my Harley instead. This issue is hit and miss honestly, my CEL came on and I jumped the wire in the jumper harness and was getting 3 flashes .. research says MAP sensor so I took a junk yard trip and pulled one. I put it in last night and ran it and it seemed ok so this morning I’m getting in it and fire it op to go to work and right away the CEL came on, I didn’t have time to read the code because I was running late but I will try when I get home today. My question is this. I noticed this has all started to happen after the exhaust has been put on before that it had the intake and headers and the headers went to a cat converter with OEM exhaust system and I never had this issue,so should I have done some tuning to it to Compensate for the exhaust??? For the intake??? Did taking the cat converter out **** with back pressure?? Any input on this I’d appreciate it
thanks.
-Dave

 

So an update:
I took the car to the shop, I left the mtn and everything was running good. I dropped it off and a few days later they called me ,saying it was fixed so I went to pick it up and they gave me a run down saying it was a bad map sensor,they test drove it and cleared the codes and it did not give them any issues .. it’s odd because I tried 2 different ones with the same issue And I also did the same thing. OK cool,

At idle after the car was warm
so I got in my car and turned it on and it was running good... I run it up the mtn and get home around 530pm and park it. This morning I wake up for work @ 5a it’s 40f degrees out side a bit chilly and I get the same issue again, I fire it up hesitation for a sec then the CEL comes on and idle hangs out @ 1500RPM. I’m leading to believe it is cold weather related somehow or it’s related to it sitting over nigh, either way it’s bugging the hell out of me !

 

Which ECU are you running?

You will need to clear the codes stored in the ECU. Pull the ECU fuse under the hood for 10-15 seconds then reinstall. Crank the car and verify there is no CEL, and verify that the LED on the ECU is not flashing codes (assuming you are still OBD0).

If you are still getting the CEL for MAP and you have tried several OEM MAP sensors (Denso), then you may need to trace wires to ensure there are no issues. Besides looking for bad wiring, you should also carefully inspect the pins in the connectors at the MAP sensor and the ECU. It's hard to visually tell, but sometimes these pins can get bent or worn out and not make a good connection, especially if they have been repeatedly connected and disconnected.

 

The wire harness is upgraded to an OBD1, The three map sensors I put into it Ive inspected them and the pins were clean and straight... I’m thinking elevation issue because I’m 4500ft in the mtns But I’ve never had this issue before and it’s fuel injected so it’s ok in that aspect... It only started when I did a run to the flatlands and came back up. I’ve noticed it’s happening a lot first thing in the morning on cold starts.. and a very well known shop has done all the work, harness upgrades to accommodate with the d15b vtec 1.5l

 

Dumb question, but are you sure you're getting a code 3 and not a code 13? Code 3 is for MAP, code 13 is for the barometric pressure sensor. In OBD1 ECU's, this sensor is present on the actual ECU board. Just the fact that elevation changes are making the car freak out made me wonder about that.

Specifically which ECU are you running?

I was not talking about the pins on the MAP sensor or the ECU, but the female pins that are on the wiring harness that connect to the MAP sensor and ECU.

 

Just a side note it was really stupid to let them remove the cat and let them install a test pipe and illegal for them to do so.

 

I’m pretty sure it’s a code 3, it’s 3 quick flashes on the dash, not a long flash or anything like that... and when the shop did a test they were also getting the same conclusion... MAP sensor... now I was doing some research and came across the IACV, if that were to be going bad could that be giving me the same issues??? Messing with the MAP sensor??? Idle sitting at 1500RPM ??? As for the exhaust I did it myself and kept all the OEM cat converter and exhaust system ... I’ll snap a pic of ECU and post it up

 

 

The ECU is pretty good about telling you what is wrong with the car. If it is telling you the MAP sensor circuit is the issue, I would focus my attention there. Do you have a copy of the FSM's for 88-91 and 92-95 Civics? If so, follow the troubleshooting guide in the 92-95 manual. You may need to reference the 88-91 manual for wire colors and locations once in the chassis/engine harness. You should also double check the ECU jumper harness you are using for possible issues.

Several sensors play into what the car idles at.

 

I do not have those... I did get in contact with the shop and I will be dropping it off and let ya know what the outcome is... thanks for all the help, might clean the IACV for the hell of it and see what that does too