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1988 Acura Integra Runs PoorlyHow to Fix Engine Performance Problems Due to Engine ModificationsYour questions answered about a 1988 Acura Integra engine modifications.
This weekly Q&A session answers your questions about cars and trucks. This week explores a 1988 Acura Integra with some engine modifications that will not run correctly. Question: 1988 Acura IntegraOk bro, my 1988 Acura Integra is making me mad. I just swapped the head with a 1988 JDM ZC (manifold, injectors, and ZC cams with the stock Acura Integra cam gears) it started getting hot and blowing white smoke two weeks ago so I flushed the cooling system and replaced the thermostat and the water pump. Nada, it still got hot so I went to Honda and got a head gasket I just changed it out Saturday. It starts up but it leans out and dies and the idle is at like 2,000 rpm. The ECU is thrown code 9 and Code 5. Please Help! Answer:Diagnostic Trouble code 5 indicates a problem in the Manifold Absolute Pressure (MAP) sensor. The MAP sensor converts manifold absolute pressure into electrical signals and inputs the ECU. Diagnostic Trouble code 9 indicates a problem in the CYL sensor circuit. The Crank Angle Sensor (CAS) consists of TDC and CYL circuits. The CYL circuit detects the position of the No. 1 cylinder as a basis for sequential injection, while the TDC circuit serves both to determine the injection timing for each cylinder and to relay engine RPM information to the ECU. The first thing you should do is check for vacuum leaks. Inspect all the vacuum lines and check the intake manifold gasket carefully to insure there are no cracks, chaffs or any lines disconnected. You have done some rather extensive engine modifications here. It is very likely these modifications are the root cause of the two diagnostic trouble codes. By changing the camshafts you've changed the valve timing and in turn changed the engine vacuum, which could explain the Manifold Absolute Pressure (MAP) sensor diagnostic trouble code. The Powertrain Control Module (PCM) is programmed with stock specifications and is looking for stock readings from the various sensors. Now the engine may be operating properly with the modifications made, but to the PCM the readings its getting are correct and it's trying to do its best to compensate for it. What you need to do is check the MAP and CYL sensor as outlined in your service manual to see if they are operating normally. Then take the same tests with it connected to the engine and compare the readings. The test according to the manual will tell you the weather or not the MAP sensor is working properly and the teat on the engine will tell you the actual readings. By comparing the two you will be able to tell if the modifications are the cause of the codes. That's all for this week. Feel free to browse the archives for past topics. And, as always, if you are stuck and need an immediate answer you can always call Vince on the phone.
The copyright of the article 1988 Acura Integra Runs Poorly in Auto Tech & Repair is owned by Vincent Ciulla. Permission to republish 1988 Acura Integra Runs Poorly in print or online must be granted by the author in writing.
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