June 23, 201510 yr I have a 86 GL-10 Turbo that I bought earlier this year.. It had set for over ten years,so it has been a project. I've got it running now, but something makes it not want to idle when cold and it hesitates when warmed up.. I bought a new Mass air-flow for it but seems to run about the same.. I was looking in the chiltons trying to test the MAF and it appears some of my wires are swapped in the plug for the MAF. Does anyone have a GL-10 turbo that runs well so I can varify the wiring?
June 23, 201510 yr Mine runs like a swiss watch, but I can't see which wires go in which connector on the plug. Try running some seafoam through the intake system. Usually there are broken nipples on the vacuum line system that runs over top of the engine, that screws up the idle. Your distributor wire connectors could be corroded either at the plug or at the distributor cap. The electrodes in the distributor cap, pick up corrosion fairly quickly that should be scrapped off.
June 23, 201510 yr Author Mine runs like a swiss watch, but I can't see which wires go in which connector on the plug. Try running some seafoam through the intake system. Usually there are broken nipples on the vacuum line system that runs over top of the engine, that screws up the idle. Your distributor wire connectors could be corroded either at the plug or at the distributor cap. The electrodes in the distributor cap, pick up corrosion fairly quickly that should be scrapped off. I've completely been through the fuel system. Cleaned the tank, changed fuel pump, changed filter, and injectors, changed vacuum lines when I've found bad ones. Also, all need ignition parts; plugs, wires, cap and rotor... There is a boot you can pull off the plug to expose your wires, but if you don't want to do that, I understand. These cars are vintage and fragile in some ways...
June 23, 201510 yr I've completely been through the fuel system. Cleaned the tank, changed fuel pump, changed filter, and injectors, changed vacuum lines when I've found bad ones. Also, all need ignition parts; plugs, wires, cap and rotor... There is a boot you can pull off the plug to expose your wires, but if you don't want to do that, I understand. These cars are vintage and fragile in some ways... I just remembered that I have an extra connector. There are 7 total connections. Starting from the left side. 1st slot has no wire 2nd slot has no wire 3rd slot, yellow/blue 4th slot, green 5th slot, blue/yellow 6th slot, yellow/red 7th slot, green/white
June 24, 201510 yr Author I just remembered that I have an extra connector. There are 7 total connections. Starting from the left side. 1st slot has no wire 2nd slot has no wire 3rd slot, yellow/blue 4th slot, green 5th slot, blue/yellow 6th slot, yellow/red 7th slot, green/white Thanks so much.. I am thinking I still may have bad gas in the system.. I'm not sure why it doesn't idle when it is cold. Ive put 3 different fuel pumps on it but they have all been kinda loud. They sound like they are straininig.. I have also changed the fuel regulator.. It looks like the wires are right...
June 24, 201510 yr you have flapper maf - correct ? hows it drive once warmed and idling correctly - you mean it only idles poorly when not at op temp ? There is a bit to do with the cold engine idle air bypass system on the top of the 85.86 thermostat housing, if you wanted to be an investigator and completely bypass its in hose and its out hose that links to inlet man chamber and put in a 1/2" irrigation tap that you can control yourself on a hose as long as you like for experimental purposes. If that is stuck shut it won;t give it the air bypass the throttle that it wants to speed up idel at cold.
June 24, 201510 yr Author when it's warm it will idle, but it still runs like it's starved for gas or air. It kinda sputters and I'm sure it's not giving me the performance it should. Yes, the MAF has a flapper.. I tested that bypass valve with an ohm meter and it was within speck.. Maybe I need to see if it's stuck? are you talking about unhooking the bypass hose from the valve on the thermostat housing? Not sure if I mentioned it before, but I also bought a new maf for it...
June 24, 201510 yr Loud fuel pump and sputtering sound like a symptom of rust clogging the pickup or fuel return line.. but you said youve already been through it. Same symptoms I had with a clogged pickup. Did you blow them out with compressed air? CHeck the fuel filter for residual sediment and stuff. If you think the fuel system is fine. Check your coolant temp sensor, timing and ignition over real good. Edited June 24, 201510 yr by SoobDood05
June 24, 201510 yr Have you backed the idle screw out (counter clockwise), so that it idles higher yet? It is just behind the turbo intake manifold and you access it from the top.
June 24, 201510 yr Author Ive idled it up with the cable adjustment.... Does the temp sensor in the radiator effect how it runs? It is currently bypassed so the fan runs all the time,, I have changed the ect in the top on the engine..
June 24, 201510 yr Check and clean all the Earth points on both the Engine and in the Engine bay when cars get a bit older these usually get higher resistance and everything works on voltage and high resistance means sensors see lower voltages than they should do and then the computer gets the wrong voltage readings and goes to the wrong look up table in the software telling it how much fuel or timing to supply. It definately sounds like it is lean and seeing as things such as Injectors have been changed as long as Fuel pressure is within spec then high resistance in the Engine management loom at either the earth points of one of the connections can cause those problems, Easiest and most likely are the earth points to check first because unlike most of the other connections they are exposed to atmosphere and can and will corrode or oxidise.
June 24, 201510 yr Author Loud fuel pump and sputtering sound like a symptom of rust clogging the pickup or fuel return line.. but you said youve already been through it. Same symptoms I had with a clogged pickup. Did you blow them out with compressed air? CHeck the fuel filter for residual sediment and stuff. If you think the fuel system is fine. Check your coolant temp sensor, timing and ignition over real good. I'm pretty sure the pick up tube is clear, but never thuoght about the return line causing a problem.. I took the tank right out at one point, cut a hole in top of the tank and cleaned it out from the inside. I have chaged the pressure regulator as well. Maybe I will try run both lines into a gas can or just blasting the return with some air...
June 24, 201510 yr Author Check and clean all the Earth points on both the Engine and in the Engine bay when cars get a bit older these usually get higher resistance and everything works on voltage and high resistance means sensors see lower voltages than they should do and then the computer gets the wrong voltage readings and goes to the wrong look up table in the software telling it how much fuel or timing to supply. It definately sounds like it is lean and seeing as things such as Injectors have been changed as long as Fuel pressure is within spec then high resistance in the Engine management loom at either the earth points of one of the connections can cause those problems, Easiest and most likely are the earth points to check first because unlike most of the other connections they are exposed to atmosphere and can and will corrode or oxidise. by earth points do you mean ground? There may be a fuel connections I haven't cleaned yet, but I have cleaned a lot of them already...
June 24, 201510 yr Author Check and clean all the Earth points on both the Engine and in the Engine bay when cars get a bit older these usually get higher resistance and everything works on voltage and high resistance means sensors see lower voltages than they should do and then the computer gets the wrong voltage readings and goes to the wrong look up table in the software telling it how much fuel or timing to supply. It definately sounds like it is lean and seeing as things such as Injectors have been changed as long as Fuel pressure is within spec then high resistance in the Engine management loom at either the earth points of one of the connections can cause those problems, Easiest and most likely are the earth points to check first because unlike most of the other connections they are exposed to atmosphere and can and will corrode or oxidise. I agree, it is running lean. When I check the plugs there is no residue or carbon buld up. They are tannish in color and the insulator is yellowed...
June 24, 201510 yr For cars with over 250,000 miles, the ground wire looses it conductivity at the end that connects to the body. That connection is just in front of the battery, on top of the main body cross strut. It is clearly visible. When the engine is running, that wire at the connection will get hot enough to burn your hand. You would then need to replace that wire with a much lower mileage or new wire. That is what the Aussie is referring to. Another important wire connector for engine performance, is the black wire connector at the hot battery terminal. That wire then connects into the bottom of the fusible link box. It also gets brittle and loses it's ability to conduct electricity, at that connector. You would need to splice in a new wire there because you cannot remove the other end from the fusible link box. Just try and bend the wire right next to the connector. If it is hard to bend, then it has become brittle and lost it's ability to conduct electricity.
June 25, 201510 yr Author The car has 157,000 on it, but it has been sitting for about 13 years, so I will check those connections. I have blown air through the supply and return gas lines.. They seem to be free.. I'm not sure that the gas isn't still a little tainted.. I am trying to run this tank down before I get more gas. What do you all think about octane boost?
June 26, 201510 yr 13 year old gas? There is your problem right there. Dilute it with new Premium gas, in order to bring the octane up.
June 27, 201510 yr Author 13 year old gas? There is your problem right there. Dilute it with new Premium gas, in order to bring the octane up. Well, I emptied the tank and scraped the tar out of the bottom of it.. At least as much as I could, but the new gas I put in may have mixed with the leftover residue... I'm going to run this tank out, and sea foam, and reafill it...
June 27, 201510 yr after running or try to run 9 year old fuel, ran successfully on fresh, but let sit, whatever tar n gunk from either oil or fuel, two rear most cylinders copped stale fuel smelling black shiny sticky gunk on the valve guides and bent two push rods requiring both heads off ...blah blah. All I can suggest is you try turning engine over by hand next few restarts to ensure nothing has disolved in the tank, like barnacles inside and acrried through to rest of fuel system and hit your valves like mine did !
June 27, 201510 yr I had my tank boiled out by a local radiator shop. I didnt want to take a chance of having sediment of stuff that had broken loose clogging up the pickup or fuel system again. Just remember confirm proper ignition system operation as well. They can both cause this type of issue.
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