CptCorN Posted June 6, 2006 Share Posted June 6, 2006 I've been searching around for an answer for some time.I have a l28et with su carbs.The motor revs fine in neutral but actually driving it giving it any gas at all boggs her out good, im no su expert but I want to think thats my problem, plug wires look good, new cap for the dizzy... it just seemed to happen while driving home today. I thought maybe I was experiencing vapor lock since it was hot and humid today, but even with the motor cold it does the same thing. Quote Link to comment Share on other sites More sharing options...
Yokohama Posted June 6, 2006 Share Posted June 6, 2006 First, I would get a unisyn and follow the adjustment procedure in the FSM to make sure the carbs are in adjustment and synchronized. I would also pull the tops of the carbs and look at the internals and clean them in carb cleaner. Also make sure that you have damper oil in the carbs. I like to use 20 weight motor cycle fork oil (as it is hard to find 20 straight weight motor oil). Make sure that all your vacuum lines are good and have no leaks. !!!!!Really look at the line that goes to the vacuum advance on the distributor. If there is not enough signal going to the distributor module, then you can suffer drivability problems. On that note, maybe get a vacuum hand pump and pull a vacuum on the vacuum advance module to see if the module is holding a vacuum. If the module will not hold a vacuum (leaks down), then you may need a new one. I would try these first, as you have an SU system, there is only so much it can be. Also adjust ign. timing using the FSM Quote Link to comment Share on other sites More sharing options...
CptCorN Posted June 6, 2006 Author Share Posted June 6, 2006 Thanks for the insight... I reset the carbs using a meathod as described by a close Z fanatic of mine... Replaced plugs, wires, distributor cap (couple weeks ago)... I'm getting spark... I notice I don't have this problem when the motor is coldish and it runs fine for a couple minutes. It's almost like its not getting enough fuel underload to spin the motor... Quote Link to comment Share on other sites More sharing options...
dasz33 Posted June 7, 2006 Share Posted June 7, 2006 Double check the oil in your carbs. Make sure the float bowls are filling to the proper level. Follow the FSM for setting the SU carbs. Im not discounting your Z Fanatic friend, but some people treat the carbs like there is some black magic involved. The FSM or even the Haynes manual will properly set up the carbs and get you going. Then you can use your black magic to tune them for peak performance. If youre not getting enough fuel, perhaps the carbs pistons are not coming up. Take your air cleaner off and rev the motor to see if the pistons rise when you rev the motor. If they dont come up, clean everything again and make sure the piston slides smoothly up and down. Quote Link to comment Share on other sites More sharing options...
CptCorN Posted June 9, 2006 Author Share Posted June 9, 2006 So I was feeling ambitious a couple nights ago and ripped the front carb apart. We were having problems with the float not sutting off the fuel before so I decided I would start there. I cleaned everything up and found a chunk of something in the piece with the ball in it. I'm not sure if it was there before or if I accidently got something in there while cleaning it up. Anyways, everything looked good, I put everything back let the car warm up and took it out to see if it was still doing the same thing. Gave it some gas and its like nothing changed... So the next morning I took it to work, and there was no problem at all and so far as of today it hasnt shown itself yet. I'm gonna go through both carbs again and replace all the gaskets and just clean them up. Just wish I knew specifically what the problem was. Quote Link to comment Share on other sites More sharing options...
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