zero Posted November 14, 2006 Share Posted November 14, 2006 So I just bought a 77 2+2 after having owned a 72 for a few years and the car seems to have some small fuel injection issues and I wanted to see where you guys thought I should start tracking down the problems. First, though probably not fuel injection related. The car apparantly runs hot. The gauge reads probably a little more than 3/4 of the way to the hot end, but its a solid reading. Driving slow in traffic, fast on the highway, A/C on or off the gauge doesn't move once it reaches that point. I am thinking its probably the thermostat or the gauge. so I am going to do stat first and hope for the best. Second, the car idles high. When I first picked up the car the throttle was sticky so I chalked up the fast Idle to that. but after I wd40'd the linkage, the stickiness went away but the idle still generally hovers around the 1300-1500 range. I have seen it idle around 1000 once or twice, but generally once it has warmed up it stays higher. Now my first thought was to simply adjust the throttle stop, but I figured that there might be some fast idle valve or something that I should check first, and I wondered if it might be related to the high temps I have been getting. Third, I figured I'd ask what emissions related stuff I could/should remove from the engine to free up power or generally simplify things. The car will have historic plates so emissions inspection is not an issue. The car is a 77. This is the best pic of the engine I have right now. If someone could point out what is necessary and what isn't that would be great. Thanks alot. -will Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 14, 2006 Share Posted November 14, 2006 I'll start with your temp issues. Could be the thermostat or it could be a malfunctioning sending unit. I would replace the both of them at once as they are both cheap items. Typically if the gauge goes bad it won't read high, it'll drop low. The high idle won't be due to temps as if it's actually running that hot the fuel will start to vapor lock and it will run rough and low idle. I would suggest checking for vacuum leaks around the intake. More than likely it's the intake/exhaust manifold gasket that leaking. Also check the rubber boot that connects the AFM to the throttle body. it should seal tight around the ends and not have any holes in it. Stretch the rubber out as you're checking it and look for pin holes from the rubber dry rotting. For clearing out the emissions junk, it won't really increase the power any, but a lot of people like the clean look better. You can remove and cap off the egr valve on the right side, the auxilary air regulator (only used for cold starts), the cold start valve, and the high idle diaphram if you don't use/have the AC. If it gets cold you may want to keep these systems as they do help a lot when starting your car in the morning. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted November 14, 2006 Share Posted November 14, 2006 Nice Z and it looks like it is unmolested. Good find. Agree...running hot would be either the fan clutch or the thremostat. Fast idle means that too much air is going into the intake manifold. In all the FI Z's that I have played with 76, 77, and 78 when you unscrew the oil cap or pull the dipstick, the idle should drop and the car should just about stall. If not, somethings wrong with the air side of the FI system. RULE #1 Don't start taking things off the motor to simplify UNTIL you get it running right. Check and listen for hissing air leaks, BCDD Valve (under the throttle body) stuck open, Air Bypass valve stuck open, missing or cracked vacuum hose (VERY COMMON) ANYWHERE in the whole car, fast idle servo for the A/C stuck. Also, I don't think I see a vacuum bottle anywhere. There should be one somewhere. Check its hoses. Quote Link to comment Share on other sites More sharing options...
zero Posted December 12, 2006 Author Share Posted December 12, 2006 ok so ive been through the car and I found one broken vaccuum line that went to a canister which was on the sparkplug side of the engine bay. I quick fixed that, and it doesnt seem to have done anything. can someone post a pic of the air bypass valve and the ac fast idle valve and what position they are supposed to be in so I know what to look for. Nothing seems to happen if I unscrew the oil cap or remove the dipstick Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted December 12, 2006 Share Posted December 12, 2006 You've got an air leak somewhere, I'd bet money on it just from your description. Look at all the stuff naviathan mentioned in his post. Especially check the boot between the AFM and throttle body. Take it and spread the pleats open, looking between them for cracks in the rubber. Air leak on this system cause a high idle. Check all your vacuum hoses, replace, vacuum hose is cheap, unless they are brand new. For this system to run right it has to be air tight. When you first fire it up, and the engine is cold, pinch off the line running to the air regulator. It's the big one (like 1/2") on top of the intake manifold. When you pinch it off, the idle should drop lower. Download and read the EFI bible. It's the factory manual for this system. Search EFI bible or bible on this site and you will find a link. It explains how the system works in very simple terms and how to diagnois it. The crankcase is vented to the intake, so the pvc lines, the oil cap, the dip stick... everything has to be air tight. The air regulator may be gummed up with carbon, take apart and clean if above test doesn't show results. Tell us what happens and we'll try to make more suggestions. It's a good system, you'll like it once you get it running well, don't give up on it. good luck! Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted December 12, 2006 Share Posted December 12, 2006 Have a read of this link..... http://www.atlanticz.ca/zclub/techtips/EFI&fuel.htm LARRY Quote Link to comment Share on other sites More sharing options...
zero Posted December 13, 2006 Author Share Posted December 13, 2006 Ok so upon closer inspection of the afm boot I noticed that where the thick vaccuum hose connects the the boot, its just a hole poked in the boot with silicone sealant around it. When I stretch it and say allow more air to enter, the engine dies down which seems somewhat counter intuitive but whatever. So I guess I need a new afm boot. I was wondering if that elbow that connects to the boot is stock, or what. Thanks Quote Link to comment Share on other sites More sharing options...
zero Posted December 13, 2006 Author Share Posted December 13, 2006 .... and also if someone had an afm boot they wanted to send me, haha. Quote Link to comment Share on other sites More sharing options...
spacecase70 Posted May 17, 2007 Share Posted May 17, 2007 my 76 280 is all stock and i am haveing a problen with it running smoothly. The car seems to run alright when you are driving down the road ,but then it will buck,or cut out, and then come back online. sometimes it will start to run from a normal idle and start surging, with the idle going from400-800 rpm's? this is driving me batty. i took it to a smog shop and the co was .3 and the hc was around 1200-1400ppm now i was told it was misfiring at all ranges. I changed the dizzy from a duel pickup to a single pickup and the car seems to run the same according to the EGA can someone please give me a clue or help me to figure out what may bne the problem? Quote Link to comment Share on other sites More sharing options...
naviathan Posted May 17, 2007 Share Posted May 17, 2007 Talk about pulling threads from the past... Check fuel pressure, timing, plugs, filters, cap, rotor, wires, coil, etc... I'll bet you'll find your problem in the fuel pressure, but a good reading of the plugs will tell us much more. Quote Link to comment Share on other sites More sharing options...
spacecase70 Posted May 17, 2007 Share Posted May 17, 2007 the plugs were oily but there is no fuel smell or taste in the oil( yes i tasted my oil ) Quote Link to comment Share on other sites More sharing options...
naviathan Posted May 17, 2007 Share Posted May 17, 2007 Oily? Wow, that's gotta be a really bad set of rings. Have you done a compression test? Quote Link to comment Share on other sites More sharing options...
spacecase70 Posted May 17, 2007 Share Posted May 17, 2007 154 psi average, it also smokes a little bit only under acceleration at cruise and idle, no smoke, and yes it is blue smoke. it also smokes when i high rev the motor while in neutral Quote Link to comment Share on other sites More sharing options...
Guest Sleepy-z Posted May 25, 2007 Share Posted May 25, 2007 Small advice worth trying.... First off, your temp should drop when you open the heater core....put it in defrost, then its probably not reading right if it doesn't drop a little. Second try a 160 or 180 thermostat, I run a 180 winter and 160 summer in mine. It will run 1/3 on the guage with a 160 and about halfway with the 180. For the idle you can adjust it, one thing I found was sometimes if I lift the gas peddle up will its running I can make it drop some so there is a small issue with the peddle itself on mine. try adjusting it, on my 75 there is a spot for a flat head screw driver near the throttle body to make adjustments, it has a spring around it and is pretty noticable. Quote Link to comment Share on other sites More sharing options...
Daeron Posted May 26, 2007 Share Posted May 26, 2007 spacecase: before you posted, there was a link to altanticz.ca blah blah.. find that link, and on that link you will find the EFI bible. Download it, print it, print another copy for "shop use" and READ IT FOURTEEN TIMES. I have heard tell of people walking up to EFI Z's that had sat in a field for ten+ years, they made sure that the engine had good gas and checked each component, made sure it passed all tests, and the car would fire right up and run smooth. Also, check the PCV system and make sure it is operating properly. http://carfiche.com is also a good place to download your complete FSM fr 76.. it may be "temporarily not available" but it will be there soon enough. (they rotate which ones are available for download, to conserve on bandwidth.) In the future, it is more helpful to start your own thread than to "piggyback" on someone else's Quote Link to comment Share on other sites More sharing options...
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