Sorry this is long but I wanted to include as much detail as possible to my problem. I am not shotgunnig to replace parts.
I admit to being a CIS newbie. I have managed to stay away from it by having two cars of my own with webers. I did a search and could not find the information I was looking for.
The car is a 73T with a 76 2.7 running with a 75 CIS system. Most of the manuals cover the really early (73.5) or the late (78+) CIS systems. The early system is vastly different and the late systems have more stuff that the 75 CIS does not have. For example there is no AAR on this motor. I can only find a Cold start, Air device, WUR, Throttle body, air plate, fuel dist and some injectors.
Background:
The engine in question was swapped in last Jan and has been sitting not driving. The 2.7 long block was swapped in after the other 2.7 had problems at the track. Now, Its time to get this car on the road. The car is at my house for two weeks while the owner is away on business. I WILL have it running when he gets back even if it means I have to learn the CIS system.
All joking aside, here is what we did during the engine swap.
The injection system was complete cleaned and revamped. Airbox cleaned and inspected to find no cracks. Pop-off installed and working correctly. New air boot, runner sleeves, injector sleeves and o-rings, and new injectors. The injectors were replaced after 4 were found to not emit fuel. The fuel dist and air plate were disassembled and cleaned. The fuel dist was not taken apart. It was cleaned by blowing solvent through until clean (eww that was nasty). The plunger is now very free. The air plate is properly centered and height adjusted per factory manual. Fuel pressures are right in the middle of the specified range for cold, warm and bleed down.
previous symptoms: Car stumbles and will not take throttle. Lots of popping through intake. Sounds very lean. Will not idle and barely drives.
Here is an update from my Saturday of turning wrenches. I still have some problems.
I need help!!!
I got the car to my house on Wed night. It did not run well at all. First order of business was repairing the non-functioning alternator. This was easy, two crossed wires would not create an excitation field. At least Df was grounded and it did not short the alt. Simple fix.
Today I pulled the air plate and fuel dist. I have set the metering plate to the factory specified dimension, ie. just below the right side of the taper. Next I pulled the throttle body and cleaned it out. Lots of black crud came from the air bypas passage. I readjusted the plate and it seals tightly. The only air getting through should be via the bypass and idle speed screw. All vacumm lines are new and sealed tightly.
I got the car to run stabe enough to check mixture. It was really lean. Gunsun read 0% CO! Many small adjustments in the CW direction brought this up to the JWW recommended 3.5%. Wow the car runs great there. Great bark with throttle opening and fairly responsive throttle for CIS.
There is one problem. The car idles at 2500 with the idle screw completely closed. HMM this is not good. Maybe its timing.
I pull the dist, clean the sticky plates put it back in and fire it up. While running I retard with the timing light and get to 5 ATDC. Idle slows for a second and then cuts off. I can not restart until I rotate more advance. Maybe timing is not the problem. Must be an air leak behind the throttle body.
A quick search mentiones the AAD having problems and leading to high idle. I figure the best thing is to disconnect it and see. I pull the vacuum line from the AAD and plug with a bolt. I still have high idle. No change. I do the same with the vacuum side and still no change although the engine tries to die like I would think false air would do.
I pull an injector and put the trigger gun from the compressor in the hole. It seals nicely with the o-ring. 80psi and it sounds like there could be an air leak. I can't really tell since the noise is just amplified inside the airbox. I can't feel any air coming through anywhere. Top, bottom, sides, intakes, throttle body. Nothing! I can open the idle screw and get air out. I don't know where the air driving the system is.
I finally pull the entire CIS system. What a PITA! I just hope I can get it back on. I don't notice any cracks, leaks or otherwise in the air box. I finally decide to split the airbox and reseal. I pulled all the screws, separated the halves and find nothing but old sealant. I clean it all up and reseal with black silicone. It should not leak at all now, if it even did before.
Meanwhile, I check the wiring. The clip harness to the cold start injector is completely fried as is the surrounding wires. It appears that a common connection point using a crimp connector is the origin. This is where the power splits for the WUR, cold start and whatever connection goes to the air metering plate. So, before I repair this wiring...
Where does the signal for the cold start come from? How does it act upon the injector? Is it a solenoid valve to start some fuel spray? Where does the on/off signal come from?
What does the connection to the air metering plate do? Maybe this is the switch to show when the car is starting to squirt fuel through the cold start injector. If so, does power come from the yellow wire going to the starter?
How important is the power connections to the WUR? What exactly does 12V do to the WUR?
I notice a switch on the throttle body that is actuated using the linkage. There are no wires going to this switch. Is it needed? What does it do?
Any ideas where to look for an air leak? I swear this system is tight! I checked it with a propane torch. No change. The oxygen line from my torch. No change. The only change I could get was using the acetylene side of my torch when placed under the air metering plate. I guess this means its just sucking it into the intake. I checked all the injector inlets, the intake gaskets, the 6 runner to airbox gaskets the throttle body, all vacuum lines, the underside of the intake above the fan. No leaks. I don't know where that air is coming from.
Thanks for educating me on the details of CIS. Now let the lecture begin.
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