I have an 88 crx dx obd1 converted with b7 intake manifold and was running good. Just swapped in a y8 hooked everything up started it up and just dies on idle I have to keep on the throtle. Then took off the cap on the port that was used for the evap and then will run but idle at 2-3 grand. If I put my finger half over the vaccum port it will bring the idle down. I've been searching and everyone just has it capped?? I was thinking I need some sort of vaccum pot but haven't seen anyone run one and never had to run one with my b7 setup?

 

You're spelling something wrong here...

Have you tried adjusting the idle screw yet?

 

What style of map sensor do you have? Is it on the firewall or on the T/B? Make sure it gets unported vacuum, as in connect it to adequately receive proper pressure differentials directly from the plenum or unported sources on the T/B.

 

It's on the firewall I'm pretty sure I must have somthing in one of the ports on the throttle body that isn't letting air in on idle I'm going to take it off tomorrow and clean it

 

Cleaned throttle body and made sure all ports were clean and flowed properly but I still have the same problem. I think it must be something to do with the ivac system It was an auto y8 intake manifold that I drilled and tapped so the ivac would fit but maybe the wholes arent lined properly or something mechanicly is wrong with the part on the bottom of the throttle body that lets the air in nos sure if i can test it

 

checked the intake manifold seems like I tapped and drilled correctly but still isn’t getting enough air. I can get it to idle around 500 rpm bumping up and down sputtering and wanting to turn off. Inspected the fitv seems to be working but have no idea what the proper setting is for the plastic screw in piece that holds it together tested the thermostat in it and it is working . Its definitely needing more air form some place but am not sure where. Looking for a diagram or article that explains the idle system cant find anything only about vacuum lines and fluctuating idles

 

This worries me a bit. I am not criticizing your craftsmanship, but trying to fit an oversized IAC motor onto a manifold is definitely questionable no matter how good of a job you did. Your idle will be sh*t if everything isn't perfect... Anyways, check the vacuum routing diagram for your map. If I remember correctly, the Y8 throttle body mounting bolts are different than the stock A6 t/b. So, which throttle body are you using? Use a Y8 one and just undo some of the conduit so the MAP pigtail will plug in and then you won't have to worry about a proper MAP signal due to mismatched hoses, et al. Also, use a Logic Probe, or even a 9v battery if you don't have that tool, and visually verify that your Idle air control motor solenoid moves. Forget the FITV, you don't need it and it will not affect your car's operation, unless it's out of adjustment, then it would idle too high.

 

I'm 99.9% sure I drilled the intake manifold out correctly measured it against my b7 intake and all the holes are the same. It's not leaking air I have sprayed intake cleaner around everywhere and no leaks and even with out the IAC I should still be able to get it to idle and not die without having to hold the throttle plate open a bit. I'm using the b7 throttle body and it bolted on fine. Tested the IAC motor it it is moving back a forth.

 

Backprobe the MAP sensor to determine if it is working appropriately. Find the input signal voltage (will not have fluctuating voltage) and then reference. Backprobe the reference voltage wire (the wire that has a fluctuating voltage) and ground the other multi-meter ground lead and test for voltage at idle up all the way to half of full engine speed. You should see between .7V to 2.0V, at the most, without a load. If you see those voltages, then the sensor is hooked up correctly and functioning properly. If not, then recheck the vacuum hose routing to the UNPORTED vacuum connection on the throttle body. If there isn't an unported location, then run new vacuum hose directly to the manifold somewhere. If the voltage is still wonky after that, then replace the sensor. Also, hook up a vacuum gauge to your brake boosted vacuum port on the back of the intake manifold and see how many inches of mercury can be achieved at idle and half of full engine speed without a load. If you have a fuel pressure gauge hooked up within the system, include that pressure too please. And, fyi, without a functioning IDLE Air Control Valve, the car won't IDLE... the component's name denotes its function. GOOD LUCK!

P.S. include a picture of your hooked up map sensor and its hose routing please!

 

Tested map sensor and voltage all seemed to check out even swapped in another another know properly working one and no change. Hooked up a vacuum gauge at and had a reading of 10-12 inches at idle and but will drop to as low as 4-6 because of the erratic idle. I get a reading of 18 at half throttle or anything pretty much off idle. Which makes me think something is up with the timing or valves. The car also seems to run extremely rich and had a tone of carbon build up but no codes.

 

I did a compression test and showed 200 across all four cylinders would like to do a leak down test but don’t have a tester at this time .hooked it up to the vacuum gauge again and its telling me that my timing is late? I checked ignition timing and advanced it as much as I could it made a small difference but not enough to make it run correctly. I'm assuming my mechanical trimming must be off but not sure how that could be I double checked my cam gear and everything is lining up properly at tdc and if it was a tooth out I think it would run much worse then this. Do I need an adjustable cam gear to advance it a coupe degrees or is there something I’m missing?

 

have you set proper idle per the manual?

 

Yes probably done it 10 times but doesn't mater if I can't get vacuum no matter what I do at idle

 

What engine? Did you change the TB along with the IM?

 

I used the TB of my b7 manifold and but it on the y8 It's a y8 with a crower stage 2 cam with 10:1 comp bought it off a guy and seen it running the block was milled slightly wondering it would be enough to put the timing off. He was running a adjustable cam gear but only had it advanced 1 degree.

 

I re read your thread a few times, and it honestly just sounds like you need to adjust the idle screw to let more air in. Keep the evap port blocked if you need to.

 

It's not the idle screw I've adjusted it and even takin it out and still don't have enough air to make it idle properly and if it was the screw I should have proper vacuum off idle which I don't

 

I'll recap what is going on to make it more clear and give more information. I can get the car to idle with all vacuum ports plugged and routed properly at about 800-900 rpm where the car seems to run the best anything below that it will pop/ slightly miss and want to die. The throttle body is making a hissing sound from the top port which gives air to the iacv and the idle screw. I went through the idle learn routine (done this about 10 times) and everything seems to be fine go to start my car later that day and its back to idling at around 500 rpm?? Then I go to drive it around the block letting it warm up then it wants to idle at 2-3 grand but will sometimes slowly go down to about 1300 after about 10-20 seconds. While driving if I am off the throttle gearing down the car really jerks if I am below 2500 rpm but accelerates fine and seems to have plenty of power. Tested the vacuum in the manifold with a gauge and tells me that I don't have enough vacuum in the manifold and is telling me I have a leak or my timing is off. Checked for leaks went over every hose and gasket no leaks. Checked the mechanical and ignition timing and both are set properly. running out of ideas tested almost everything I can think of.

 

Recorded a video on my iphone not the best quality but you can see whats going on. The car is fully warmed up and is at 800 rpm with the iacv unplugged. The gauge is reading at about 14 inches at idle and 18 open throttle then drops to almost zero, bounces around a couple times till it evens out again.

http://www.youtube.com/watch?v=1wkr8...ature=youtu.be

 

sounds like timing to me, although the fact that it wants to idle at 2-3krpm is confusing to say the least.

 

The valve timing looks dead on when I like the cam gear up with the head. the block was milled .030 which would make less than a degree off would that make it run that bad??
I guess I will order a adjustable cam gear hopefully solves my problem