My name is Russell Posted February 18, 2009 Share Posted February 18, 2009 Hey boes Got engine problems and strugling to fix it. Ok the problem is that the car is running rich and we cant lean it out. The engine sounds like its got an ugly lumpy cam/bad idle, Haynes says this is an indication of running rich. We have little to no response from the carbs mixture screw. Have cleaned carb/jets, didnt work. Have then changed to a spare carb with exact same problem. We have re routed the return as before the bowl was overfilling and it was running very rich. We now have less black smoke but def still some. We did a compression test and 2 cylinders where around 180 (190-200 is around what a rebuilt pinto normally has) and the other two around 100. UJ put oil down the bore and the compession did not change. So the rings are fine it is the valves not closing. Prob due to valve seat reccession because I dont run valvemaster. Will try reset the tappets but not sure it will fix fuck all? We are also going to replce the points on the dizzy as its showing massive signs of wear. (just struggling to get the right one at the mo) Dizzy cap and rotor is new and timing is set right. Any suggestions of were to look? Could it be the Fuel pump? What would happen if it had a hole in teh diaphrame? Need this fixed ASAP as its going to be one of Gaz's wedding car and running out of time to get it right. Gaz edit Quote Link to comment Share on other sites More sharing options...
Gaz Posted February 18, 2009 Share Posted February 18, 2009 oh yeah, have been told that it is really hard to tune a car with low or differant compression too. Quote Link to comment Share on other sites More sharing options...
Unclejake Posted February 18, 2009 Share Posted February 18, 2009 The compression difference won't be causing that ridiculous amount of black smoke (unburnt fuel). All the plugs were pretty much the same so the problem is over fueling on all cylinders. We/you can measure your fuel pump delivery pressure. I have the tool. I expect you are looking for something around 4psi. Did the mixture adjuster on the spare carb not work either? Quote Link to comment Share on other sites More sharing options...
Steelies Posted February 18, 2009 Share Posted February 18, 2009 does the float position/valve thing have anything to do with over filling bowl? Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 18, 2009 Author Share Posted February 18, 2009 The black smoke has been greatly reduced by adding the breather on the fuel tank as before i had my return fuel line pluged into it. It still smokes under high revs however. I would say the bowl was overfilling munu from the presure of not having a breather, but should be ok now. When we removed the carb there was no gasket glue whatsever near the mixture screw turns out i had gaskets in there. The main problem now is the ugly iddle. Its stalling randomly and when you adjust the iddle speed up/down it fluctuates alot in vers no matter which way you go. Quote Link to comment Share on other sites More sharing options...
Requiemk Posted February 18, 2009 Share Posted February 18, 2009 vacuum leak? Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 18, 2009 Author Share Posted February 18, 2009 vacuum leak? Checked that ... none that we could find using brake cleaner Quote Link to comment Share on other sites More sharing options...
QCADTA Posted February 18, 2009 Share Posted February 18, 2009 not something simple like buggered plugs or weak spark? Quote Link to comment Share on other sites More sharing options...
Requiemk Posted February 18, 2009 Share Posted February 18, 2009 maybe try again and spray up underneath manifold? Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 18, 2009 Author Share Posted February 18, 2009 not something simple like buggered plugs or weak spark? spark Plugs and leads are all new Coil is new ... but will double check that tonight. Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 18, 2009 Author Share Posted February 18, 2009 maybe try again and spray up underneath manifold? Will do so Quote Link to comment Share on other sites More sharing options...
Unclejake Posted February 18, 2009 Share Posted February 18, 2009 The black smoke has been greatly reduced by adding the breather on the fuel tank as before i had my return fuel line pluged into it. So you were pressurising the fuel system. That explains a few things.What fuel pump are you running. The standard mechanical one? The smoke at high revs/load could well be oil I guess. It is an older motor. If you are now getting a response from the mixture screw then fine tuning is what is required. You might need to spend some money on a diagnostic machine (I know a good guy and he is cheap) but you need to make certain everything is adjustable first. Get the points, have KKK set them (he is ways better at it than me), set the valve lash, make certain nothing else is dodgy, set the float bowl, check the float needle valve, check the fuel pressure, get a water temp gauge and go see a mechanic with an old school engine analyser EDIT: Remove the linkage from the mechanical secondary and see what happens at high RPM/Load Quote Link to comment Share on other sites More sharing options...
Requiemk Posted February 18, 2009 Share Posted February 18, 2009 You said main problem is now ugly idle, this is possibly an effect of valve/compression problem. Would pay to rectify that problem as it needs doing either way then your not wasting your time doing all these other tests. Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 18, 2009 Author Share Posted February 18, 2009 The black smoke has been greatly reduced by adding the breather on the fuel tank as before i had my return fuel line pluged into it. So you were pressurising the fuel system. That explains a few things.What fuel pump are you running. The standard mechanical one? The smoke at high revs/load could well be oil I guess. It is an older motor. If you are now getting a response from the mixture screw then fine tuning is what is required. You might need to spend some money on a diagnostic machine (I know a good guy and he is cheap) but you need to make certain everything is adjustable first. Get the points, have KKK set them (he is ways better at it than me), set the valve lash, make certain nothing else is dodgy, set the float bowl, check the float needle valve, check the fuel pressure, get a water temp gauge and go see a mechanic with an old school engine analyser EDIT: Remove the linkage from the mechanical secondary and see what happens at high RPM/Load The mixture screw is still not responding whatsoever which has us stumped.... but i guess would reflect what gaz said above that tuneing is difficult if the iddle is fluxtuating as mine is. Will happily pay someone to diagnos/ fine tune the engine, gaz and I where discussing the same thing we just need to get all these critical problems solved first otherwise it will cost a fortune having him chase the same problems we are. Will disconect secondaries and see what happens. I think you may be right Requiemk626 im sure the valves must be in bad condition and have something to do with it. If only i didn't throw out the spare two heads i had a few months ago Getting a stable idle is our main problem now. Quote Link to comment Share on other sites More sharing options...
Gaz Posted February 18, 2009 Share Posted February 18, 2009 Ive said it a million times.. The fluctuation is not the problem, it is a side effect of the problem. The car is still running rich even at idle. We need to do as UJ said. Quote Link to comment Share on other sites More sharing options...
Unclejake Posted February 19, 2009 Share Posted February 19, 2009 Ive said it a million times.. The fluctuation is not the problem, it is a side effect of the problem. The car is still running rich even at idle.. Did you guys try a completely different carb or did you rob some bits from the existing carb and if so could those bits be suspect? If you used the top of the old carb then the problem will be float/needleLet's take a look in the weekend and hook it up to my fuel pressure tester. Bring the carb book and the Haynes manual. Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 19, 2009 Author Share Posted February 19, 2009 Ive said it a million times.. The fluctuation is not the problem, it is a side effect of the problem. The car is still running rich even at idle.. Did you guys try a completely different carb or did you rob some bits from the existing carb and if so could those bits be suspect? If you used the top of the old carb then the problem will be float/needleLet's take a look in the weekend and hook it up to my fuel pressure tester. Bring the carb book and the Haynes manual. Replaced the entire carb and it still iddled exactly the same Quote Link to comment Share on other sites More sharing options...
Requiemk Posted February 19, 2009 Share Posted February 19, 2009 fix your compression first as said 2 cylinders with low compression is going to give you a rough idle Quote Link to comment Share on other sites More sharing options...
Unclejake Posted February 19, 2009 Share Posted February 19, 2009 http://www.piercemanifolds.com/carbdeta ... _DGV5A.pdf Is this the same as your one Chris? Quote Link to comment Share on other sites More sharing options...
fuel Posted February 19, 2009 Share Posted February 19, 2009 fix your compression first as said 2 cylinders with low compression is going to give you a rough idle Can of compression anyone? Nah I fully agree with Joeseph here, having half the compression on two cylinders isn't going to do good for the drivability of the engine. I would definitely get that head off (after checking tappets aren't too tight) and find out what's stopping the valves from sealing properly, and then rectify that. Did you say you had a spare carb? If so try using that and see if anything changes. Quote Link to comment Share on other sites More sharing options...
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