thnikkamax Posted May 27, 2008 Share Posted May 27, 2008 Things I've done: Spark plugs.. check Wires... check Air Filter... check TB Clean.. check Clean fuel free of debris.. check Injector voltage.. check Fuel Filter.. check So the car starts, and idles very well.. can sit there and just continue idling smoothly. What happens is I can get the car to go a bit once letting off the clutch and adding a tiny bit of throttle, but if I add more and at a faster rate, the car begins to sputter (and sometimes stalls) UNTIL I give it some more gas and then all of a sudden the car hauls. Go into 2nd, sputters, more gas, then hauls.. into 3rd, sputters just slightly, then hauls some more. 4th and 5th don't have such a noticeable problem. I just picked up the car from a buddy who did the swap but left the electrical for the next owner to take care of. The project is kinda half done, and I'm not too savvy on mechanics.. just electronics (got all the lights and junk working well). So.... I took a few pictures of some things I noticed in the engine bay that may not be up to par. Also, the A/C motor (?) is out so I'm not sure if there's something that needs to be done with that pipe in Picture C. Is that for A/C? Don't know if this means anything but in Picture B, when I take that bolt out of that hose just resting on the engine cover, the car dies soon thereafter. Connecting it to where it's supposed to go does the same thing. Also, I was running 89 octane and then I switched to 91, sputters less but comes a lot closer to stalling than with the 89. AND in picture D, I noticed I don't have the Carb canister or the mechanical fuel pump there.. but the manual wasn't much use helping me troubleshoot. Yes I'm a moron.. HELP! Quote Link to comment Share on other sites More sharing options...
woldson Posted May 27, 2008 Share Posted May 27, 2008 Take the tps cover off and clean the contacts. When it is off you will also be able to aline it as well. (Since you will be able to understand how it functions a bit better.) Quote Link to comment Share on other sites More sharing options...
thnikkamax Posted May 29, 2008 Author Share Posted May 29, 2008 The socket was brand new and I played around with it but had the same results. Things I noticed that are different in my engine bay from the Haynes manual are: No carb canister, no EGR valve, no mechanical pump in the engine bay. Could the lack of any of those, as well as an uncalibrated dashpot or faulty Air Regulator be causing this problem? Quote Link to comment Share on other sites More sharing options...
woldson Posted May 29, 2008 Share Posted May 29, 2008 AFM? Mabey there is a dead spot in the afm. Pull cover and clean well. also contacts on the tps and afm. The egr, canister and pump (fuel?) should not be any kinda problem for you. The dash pot should not be a promblem ethier since it just slows the thottle on it's return to closed postition. Check everyware for vacumme leaks. Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted May 29, 2008 Share Posted May 29, 2008 First thing, the fuel injected motor will not have a mechanical fuel pump. The fuel injection requires much higher fuel pressure. So the mechanical pump was deleted in favor of an electric pump located (stock) back near the differentail on the passenger side. I'm sure the guy added an electric fuel pump as the car won't run with out it. Hopefully it is up to the task, the injection system needs 25 - 35 psi fuel pressure. If he used the stock electric pump from the 76, you're golden. The pipe sticking out of the block in picture C is the crankcase vent. Normally, a hose would run from this pipe up to the PCV valve threaded into the bottom of the intake manifold. The hose in picture A may be attached to the PCV valve and is blocked off. You need to trace that hose down and see where it is running. The pipe that is open in picture B is the crankcase vent for the top end. It also tied into the PVC system stock. So, trying to figure out what is going on. The fuel injected motors I've had have never had even a trace of sputter or hesitation even when stone cold. My first guess from your description is that there is a vacumn leak somewhere. Like I said above, from the factory the crankcase vent system is a closed system. The vapors vented from the crankcase are fed back into the engine via the PCV valve in the intake manifold. If the guy blocked off the PCV valve on the underside of the intake, and just has the vent on the side of the engine and the top of the valve cover open, it should run OK. Some oil might spew out the vents though. For the fuel injection system to work well, all the vacumn lines must be in perfect condition. If they are all not brand new, replace them. Also, the boot between the AFM and the throttle body will often have craks in it. This could be your problem, because air enters the engine that the AFM didn't 'see'. It (the boot) often looks OK, but take it off the car and spread it open between the pleats and see if you find any cracks. Does this happen only when the engine is cold or at running temps as well? The air regulator should only effect it when the engine is cold. Keep us updated, we'll run this problem down. And if you fix it, post the fix. Search fuel injection on this site, lots of good posts, and also search 'bible' for a link to the factory fuel injection manual. It explains how the system works and will help you. Quote Link to comment Share on other sites More sharing options...
thnikkamax Posted May 29, 2008 Author Share Posted May 29, 2008 Can I use carb cleaner inside the AFM? or are you talking about pulling the plastic cover off and spraying the electrical with contact cleaner? Also, I noticed one thing when I opened her up this morning again. Take a look at the first picture in my initial post. That device at the top the manual says is the Air Regulator. I noticed I left it unplugged and the car was running with no difference. I also unplugged the connector on the left side in that picture with no difference to car/acceleration so I must replace those.. the greenish/bluish one in front of the hose. (also in that pic take a look at that small hose in the center that the previous owner sealed off.. what is that hose for?) Now when I pulled the end off the AIr Regulator, the connector was attached to a sensor that looked like a long rectangular plate wrapped with a coil. There was some oily gunk on that plate. Is it OK to spray that sensor plate with carb cleaner as well as inside that air regulator? I think this is what's causing the stall when I connect that large 1/2" I.D. hose to the cover breather I"ll check for vacuum leaks tomorrow on my day off. I've seen a lot of similar problems, but the difference about mine is that the car runs great at higher RPM.. lots of power. I'll also take apart the fuel pump to check it for gunk buildup.. got to put a clear fuel filter in the line somewhere to see what the flow looks like. Quote Link to comment Share on other sites More sharing options...
thnikkamax Posted May 29, 2008 Author Share Posted May 29, 2008 First thing, the fuel injected motor will not have a mechanical fuel pump. The fuel injection requires much higher fuel pressure. So the mechanical pump was deleted in favor of an electric pump located (stock) back near the differentail on the passenger side. I'm sure the guy added an electric fuel pump as the car won't run with out it. Hopefully it is up to the task, the injection system needs 25 - 35 psi fuel pressure. If he used the stock electric pump from the 76, you're golden.The pipe sticking out of the block in picture C is the crankcase vent. Normally, a hose would run from this pipe up to the PCV valve threaded into the bottom of the intake manifold. The hose in picture A may be attached to the PCV valve and is blocked off. You need to trace that hose down and see where it is running. The pipe that is open in picture B is the crankcase vent for the top end. It also tied into the PVC system stock. So, trying to figure out what is going on. The fuel injected motors I've had have never had even a trace of sputter or hesitation even when stone cold. My first guess from your description is that there is a vacumn leak somewhere. Like I said above, from the factory the crankcase vent system is a closed system. The vapors vented from the crankcase are fed back into the engine via the PCV valve in the intake manifold. If the guy blocked off the PCV valve on the underside of the intake, and just has the vent on the side of the engine and the top of the valve cover open, it should run OK. Some oil might spew out the vents though. For the fuel injection system to work well, all the vacumn lines must be in perfect condition. If they are all not brand new, replace them. Also, the boot between the AFM and the throttle body will often have craks in it. This could be your problem, because air enters the engine that the AFM didn't 'see'. It (the boot) often looks OK, but take it off the car and spread it open between the pleats and see if you find any cracks. Does this happen only when the engine is cold or at running temps as well? The air regulator should only effect it when the engine is cold. Keep us updated, we'll run this problem down. And if you fix it, post the fix. Search fuel injection on this site, lots of good posts, and also search 'bible' for a link to the factory fuel injection manual. It explains how the system works and will help you. Thanks for all that info.. I was still typing my response to woldson when you posted. The accelleration is better colder than after I've been driving around for a while. In the morning I warm the engine up to normal temp, then driving through the streets it only sputters in first from a stop, the rest works fine. Then down the freeway several minutes later at the exit, it will sputter in 1st as normal, then it will start sputtering at the beginning of every gear change on initial throttle. If I increase throttle it will pick up almost as if I;ve gone WOT. I have a free weekend from any other obligations so I'm just going to take everything apart and clean it all to be on the safe side. New hoses included. Many thanks to both of you for your help!!! Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted May 29, 2008 Share Posted May 29, 2008 Check the boot between the AFM and the throttle body. The more I think about this, the more I'm convinced this is it. Spread the pleats and look in there. Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted May 29, 2008 Share Posted May 29, 2008 Oh also, I read your reply to Woldson and I wanted to let you know, the air regulator only effects cold running. It is a high idle device in effect. When you first start the car and it is cold, the air regulator allows extra air to enter the engine past the throttle body. This has the same effect as the throttle body being opened slightly. It makes the car idle a little higher when it is cold and the oil is thick. As the car warms up it slowly closes. If it is full of gunk, spray it out with carb cleaner. but once the car is warmed up, it will make no difference if you unplug it as it is no longer working anyhow. There is a test procedure in the bible for it. I think you start the car cold, then squeeze the thick hose so you pinch it closed. The car should slow down it's idle as you do this. (you're effectivly cutting down the extra air it's sending) What Woldson is talking about the AFM is this. If you pop the cover off the AFM, you will see a little arm attatched to the flap. As the flap opens the arm swipes across a carbon trace. You will see the carbon trace with the cover off as well. Stick your finger into the AFM and open and close the flap and you will see the arm moving up and down the carbon trace. It is a black (brown) arc shaped surface. Sometimes gunk builds up on the surface of the carbon trace causing bad conductivity. Spraying the carbon trace with electrical contact cleaner should clean it right up. Sometimes an actual chunk of it can fall off, if that happens you have to replace the AFM. But... I don't think that is the problem. Check the boot. I'm sure that's it. These cars never bog on accel. Extra air is getting in somewhere. CHECK IT!! it will only take a second to look at. Quote Link to comment Share on other sites More sharing options...
thnikkamax Posted May 29, 2008 Author Share Posted May 29, 2008 Will do.. after work I'll take the boot out and check it. Do they sell those types of boots at local car parts stores? Quote Link to comment Share on other sites More sharing options...
woldson Posted May 30, 2008 Share Posted May 30, 2008 Dang mom'sZ you are certainly getting the "lead out"! Thnikkamax pay close attention to what Mom'sZ has specified. Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted May 30, 2008 Share Posted May 30, 2008 Do they sell those types of boots at local car parts stores? Unfortunetly... no, I don't think so. I've always gotten factory replacements from MSA. http://www.thezstore.com/page/TZS/PROD/SFC03A/11-3501 But here's what do, if you find your's is cracked, wrap it with some duct tape. This will at least allow you to drive the car and see that is what is wrong. Just don't leave the duct tape and not order a new one because eventually it will get gooey and start to fall off. Quote Link to comment Share on other sites More sharing options...
thnikkamax Posted June 2, 2008 Author Share Posted June 2, 2008 I cleaned every contact I could and checked the boot.. the boot is new, no cracks at all in it. Cleaned the AFM, and got as much carb deposit off of anything that looked like it had it. BUT I did not pop the cover off because it looks like it's usually glued on. Doesn't even look like it should be removed. There's what looks like a regulating valve screw on the AFM, I turned that all the way clockwise and that actually alleviated the problem a little. Didn't get the chance to take apart the fuel pump to see if it's clogged in some way, but I would think if this problem were fuel related that it would sputter at any RPM or throttle position, right? I'm going to check out per the FI bible where all these dead hoses need to go. I didn't check every single hose, so I'm hoping that is the last thing I need to check along with the pump just to eliminate all of these possible culprits. Quote Link to comment Share on other sites More sharing options...
woldson Posted June 2, 2008 Share Posted June 2, 2008 Mine was siliconed on. Was not too difficult. It is not overly complicated under that cover. Make sure you make marks in order to put things back to "normal" or you will start chaseing your tail. Hummm that screw usually has a cap on it, atleat all mine did. I dont believe that is one that should be ajusted. (If I remember correctly from a long time ago.) Quote Link to comment Share on other sites More sharing options...
thnikkamax Posted July 21, 2008 Author Share Posted July 21, 2008 Guys, just to give you an update on this, I ended up finding out that whoever had taken apart the throttle body to clean it reassembled it with the notched post backwards. All i did for now was instead of the throttle sensor connector facing northeast, it is now facing northwest and zip tied in place.. Ha! Looks like that post is 90 degrees turned from where it's supposed to be. No hesitation at all. Thanks to all who burned some serious brain cells along with me trying to figure this out. Sometimes it really is the dumbest most simple things. Glad I didn't burn my wallet troubleshooting though. Quote Link to comment Share on other sites More sharing options...
woldson Posted July 22, 2008 Share Posted July 22, 2008 Very nice find indeed! Congrats:) Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted September 1, 2008 Share Posted September 1, 2008 Guys, just to give you an update on this, I ended up finding out that whoever had taken apart the throttle body to clean it reassembled it with the notched post backwards. All i did for now was instead of the throttle sensor connector facing northeast, it is now facing northwest and zip tied in place.. Ha! Looks like that post is 90 degrees turned from where it's supposed to be. No hesitation at all. Thanks to all who burned some serious brain cells along with me trying to figure this out. Sometimes it really is the dumbest most simple things. Glad I didn't burn my wallet troubleshooting though. Hey, I think I am having the same problem, did you experience the hesitation when the car was in neutral? I have a '76 that I am working on and it has new: plugs, wires, cap, rotor, vacuum advance, afm, etc. No vacuum leaks. Fuel pump has been replaced but I have not checked fuel pressure. Timing is set correctly, but the hesitation can be lessened by advancing. I also have almost the exact same problem. In neutral it revs up fine. However, in gear (auto) it bogs down at the same rpm in every gear. It hasn't died but comes close, and if you floor it you can pass it up and it revs to 5k rpm just as it should. It's around 1500 rpm in every gear at an advanced timing, if I set the base timing to 7*, or stock specs, the hesitation is worse and at a lower rpm, say like 1000 rpm. I've also heard about slipping harmonic balancers, which I should have remembered to check out while I was at the car, doh! Quote Link to comment Share on other sites More sharing options...
gwnwar Posted September 4, 2008 Share Posted September 4, 2008 Take the cover off the TPS make sure the contact points are close enough..from idle to WOT..(rear set) Quote Link to comment Share on other sites More sharing options...
AK-Z Posted September 4, 2008 Share Posted September 4, 2008 Hey, I think I am having the same problem, did you experience the hesitation when the car was in neutral? I have a '76 that I am working on and it has new: plugs, wires, cap, rotor, vacuum advance, afm, etc. No vacuum leaks. Fuel pump has been replaced but I have not checked fuel pressure. Timing is set correctly, but the hesitation can be lessened by advancing. I also have almost the exact same problem. In neutral it revs up fine. However, in gear (auto) it bogs down at the same rpm in every gear. It hasn't died but comes close, and if you floor it you can pass it up and it revs to 5k rpm just as it should. It's around 1500 rpm in every gear at an advanced timing, if I set the base timing to 7*, or stock specs, the hesitation is worse and at a lower rpm, say like 1000 rpm. I've also heard about slipping harmonic balancers, which I should have remembered to check out while I was at the car, doh! DO NOT take the cover off the tps. It is not needed. Just unplug the tps and clean the contacts on the connectors, and do the same for the MAF sensor. Quote Link to comment Share on other sites More sharing options...
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