Hey guys,

My vacuum lines look odd and I did some work on my car and I forgot to plug in one of the vacuum lines, the one that goes from the map sensor to the manifold, and the car ran perfectly until I noticed it and plugged it in and the idle dropped and the motor shook the car, seeming unstable... I have some pictures of it, I was wondering if its hooked up right, its been like it since I got it, or is it something wrong with the map sensor.. or anything else.. Also a vacuum line coming out from the throttle body on the top is plugged with a bolt?? Not the one that goes to the carbon canister the other one.. I would like to make it right
Can anyone shed me some light?
Thanks!

1st picture - map sensor
2nd picture - vacuum hose from manifold
3rd picture - full vacuum line from map sensor to manifold
4th Picture - plugged line

 

Does this diagram of vacuum lines help?

 

Well myn does look a lot different from that vacuum diagram, maybe that's the problem, my engine is a SOHC ZC motor if that makes a difference, But I dont have the vacuum dashpot I think its called, the little diaphragm coming off the throttle body, is it needed? I have one off of a DOHC ZC that I could install

 

The dashpot valve is important. Download the 88-90 Civic service manual at the link in my signature. It contains additional information that should help you.

 

Alright so I finally got around to the vacuum lines and I got looking at it and I don't have a purge cut off solenoid valve, the one on the farthest right and I have a vacuum line coming out of the back of the manifold going into the map sensor (see pictures) My car is a SOHC ZC motor is that any different from the normal motor? The car was a 1.5L before. I got a dash pot put in and it starts good now but when I rev it past 5,000 rmp is idles really low and almost stalls, it did it before I even touched the vacuum lines, this is the last problem, ive fixed everything but this now, please help! Thanks!

 

Maybe the vacuum hose diagram below is a better match for your system.

Is the ECU LED under the front passenger carpet blinking a code?

Have you checked the ignition timing with a timing gun?

Have you inspected the plugs, wires, cap, and rotor?

 

Thats close but theres still that one vacuum line coming out the back of the manifold above the IACV,

I just put in a PG7 ecu from an 88 integra yesterday, the codes are code 7, 19, 20
With the other ecu PM6 I think, I had code 7 and 20 throttle position and electrical overload. I replaced the cap and rotor and spark plugs about a year ago, and Ive never properly timed it.

 

It will likely help to troubleshoot the CEL codes. Also check for blown fuses under the dash and hood, and definitely properly time the engine.

 

What about the throttle position sensor? How do I properly adjust that? I bought a new one off ebay but it still throws a CEL

 

Turn the key on but don't start. With the sensor plugged in, measure the voltage from the center wire of the TPS to ground with the throttle closed. It should be 0.5 volts. If not, loosen the screws and rotate the sensor relative to the throttle body.

Also as you open the throttle (engine NOT running), the voltage should increase smoothly from 0.5 to approximately 4.5 volts.