zc idle help wont stay running

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sparrky[SF]

New Member
i got a 91 civic i just did a dohc zc swap redid all the wiring it started right up and ran good but check engine light came on code 7 and 9 it was idleing fine though and would rev up so i turned it off and put it back together and tryed starting it and know it runs ruf at low rpms and wont stay running unless i keep it at high rpms and im still getting code 7 and 9 any help would be awsome first dohc swap im not sure if i have all the vacume lines right either i cant find a diagram so if anyone has a link or pics that would be cool thanks
 
code 7 and code 9 one is the tps sensor when i swaped the motor i had to use the old one off my d15 and it sits on there diffrent it was all i had but i dont think this would make it not run and the other is the cam position sensor i read that neither one of these would make it not idle it runs great when i give it gas it just wont idle and runs really ruff at low rpms thanks
 
The TPS will definately cause a problem if its faulty. Fix the problems that the ecu is throwing codes on and let us know what the outcome is. When your ecu throws a code, thats not all it does. It can put the engine into a "mode", which in turn will affect drivability.
 
will do got to wait till monday for parts its just weird because it was running fine at first and every time ive had the tps go out it just messed with the idle not actually keep it from running at low rpms its weird im gonna go to the junk yard and get a new tps and a cam postion sensor hopefully that does it but im doutfull
 
Usually, when you have vacuum leaks on the intake manifold, you will get a surge in your idle, not just a "low" idle. Try adjusting the idle screw on the throttle body so your idle comes up a bit and fix those sensors and you should be on the road to recovery unless something else is causing your problem.

When you ask for help online, its hard to give an exact answer to your problem. If it were in person it would be 100 times easier (for me atleast), because I can diagnose it right then and there without using the proccess of elimination.
 
i got a 91 civic i just did a dohc zc swap redid all the wiring it started right up and ran good but check engine light came on code 7 and 9 it was idleing fine though and would rev up so i turned it off and put it back together and tryed starting it and know it runs ruf at low rpms and wont stay running unless i keep it at high rpms and im still getting code 7 and 9 any help would be awsome first dohc swap im not sure if i have all the vacume lines right either i cant find a diagram so if anyone has a link or pics that would be cool thanks
code 9 on the DOHC ZC usually means that the camshaft timing is not correct or you have a problem in the wiring to the Cylinder Sensor - the sensor itself rarely goes bad - was this a DPFI to MPFI swap and if so, did you switch the wires on the TPS? - if you have a vacuum leak, the idle will not be low, it will be high - here is vacuum diagram
 

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