robaru Posted May 29, 2004 Share Posted May 29, 2004 Does a 1987 GL Carbed Sub have an ECU? If so, Where does it set? I've been chasing a timing problem for awhile (I think), and I'm looking for possible culprits. What are the symptoms of ECU failure, and are they common? I'm full of questions. Any advice would be great. Quote Link to comment Share on other sites More sharing options...
snowstormer Posted May 29, 2004 Share Posted May 29, 2004 someone please correct me if i am wrong!! as far as i know if the car is carbed, it does not have an ecu. the fuel injected cars do and it is located under the steering column(sp?). the only time a carbed car would have an ecu is if it has an electronically controlled feedback carb. again, there are many people on this board that knows more than me so you might want to wait for a confirming response. Quote Link to comment Share on other sites More sharing options...
robaru Posted May 29, 2004 Author Share Posted May 29, 2004 I appreciate the response. Frankly I hope it doesn't have one. Probably expensive to replace. I have been chasing a hesitation in the accelleration since I purchased the car. Two weeks ago I completed putting a short block from a wrecked car in it, as it lost a big chunk out of one of the valves on the #1 cylinder, and it burned alot of oil. It was a smoker. I also put remanufactured heads, and all new gaskets, thermostat, ect. Needless to say, the new motor did not fix the acceleration problem. 5 months ago I put a remanufactured carb on as well, with some improvement, but not it yet. In the last couple days I've taken the distributer appart, cleaned it, even polished the bearing races till now the vacume advance is nice and smooth. I can't detect any play in the shaft, though at idle the rpm does vary some. When accelerating, the power ok until about 1/2 throttle, then it hesitates until you get to 3/4 throttle, then it takes off. It won't hold at 60 mph without constantly playing with the throttle to keep it at that speed. So today, on the way to work, at the top of the same hill that I broke my valve on, the car starts making a loud clicking coming from the front right side. I have no loss of power (yet) like I did before, but sounds similar. I checked to see if it was a leaking exhaust gasket, but no such luck. So I'm about to compression test it tonight, but I'm still wondering if I'm getting that side to hot due to misfiring and torching valves because of that. What else could be responsible for the lack of power from 1/2 to 3/4 throttle. I'm still checking and have found no vacume leaks. I did get it hot the other day setting in traffic, but to quite to the red on the dial, and it didn't boil over. Since then I hardwired the electric fan on and it runs right in the middle of the temp dial, as it was this am at the top of the hill when I noticed the noise. So could it be the coil? Sorry I'm so long winded. Quote Link to comment Share on other sites More sharing options...
subarubrat Posted May 29, 2004 Share Posted May 29, 2004 There were ECUs on some carbed vehicles. The BRAT had them on some 82s for sure. It is mounted under the steering column on a plate with 4 bolts. The ECU only dealt with fuel delivery on the ones that I have seen and timing was still strictly mechanical. On my 82 back when I had the 4cyl in it I had problems with the ECU and I simply disconnected it and threw it away, the truck ran fine after that for the rest of the time I had the 4cyl in it. Quote Link to comment Share on other sites More sharing options...
robaru Posted May 29, 2004 Author Share Posted May 29, 2004 Thanks for the reply. Beautiful Brat by the way. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted May 29, 2004 Share Posted May 29, 2004 Feedback carb models have ECU's. They can be black or gold, and are under the steering column. The ECU in no way effects the timing on these cars. It's not capable of such a thing. It controls fuel delivery only using a coolant temp sensor, and an O2 sensor. GD Quote Link to comment Share on other sites More sharing options...
robaru Posted May 30, 2004 Author Share Posted May 30, 2004 So if my car doesn't have an 02 sensor site on the cat, and no black or gold box under the steering column, that's one less thing to wonder about. Thanks. Could a tiring fuel pump be the cause? I put a gauge on it at the carb and got 4 psi. Coil? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted May 30, 2004 Share Posted May 30, 2004 4 psi is too high - stock should be around 1-2 psi. GD Quote Link to comment Share on other sites More sharing options...
robaru Posted May 30, 2004 Author Share Posted May 30, 2004 So would a coil going cause the poor midrange accleration? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted May 30, 2004 Share Posted May 30, 2004 Hard to tell. Test it. Any good manual will give you a resistance value to check it against. GD Quote Link to comment Share on other sites More sharing options...
subarubrat Posted May 30, 2004 Share Posted May 30, 2004 I would also go to NAPA and pick up their adjustable fuel pressure regulator. It is a small chrome unit with a dial from something like 1~8PSI, that can help you fine tune the pressure. Quote Link to comment Share on other sites More sharing options...
robaru Posted May 30, 2004 Author Share Posted May 30, 2004 Thanks for the help. I'll go test the coil. I just got home, and the clicking sound didn't start again until about 4 miles. Still no loss of power, but noisy. When I did the motor swap I pulled the oil pump off to look at the gaskets. I've read on this site about having to put new gaskets on due to air leaking by and making the hydralic lifters noisy? Hopefully that is the noise. Quote Link to comment Share on other sites More sharing options...
robaru Posted May 30, 2004 Author Share Posted May 30, 2004 Well I compression tested it last night. 140-150 psi on all. I played with the timing again to try to get rid of the lag on accelleration. Is it normal for there to be about a 5 degree change in timing at idle when the vacume advance is unplugged? Also, how far should full advance be. The dial ends at 20 BTDC I think, is full advance beyond that? I appreciate the help. I can't seem to find this in the manual. Quote Link to comment Share on other sites More sharing options...
rallyruss Posted May 30, 2004 Share Posted May 30, 2004 the vac advance may effect timing that much. I dont tink you are going after a bad coil. BTW resistance testing a coil is a poor test. I have seen bad coils with good resistace and coils that worked just fine with bad resistance. coil would be a problem under a load. make sure you have the vacume to the disty set properly. 4 psi of fuel pressure is not too far out there was that runing or static? try disconecting you egr temporarily. just pull off and plug the vac line. egr is normaly aplied during part throttle. lots of these carbs have problems with loose throttle shafts. give it a wiggle test while running and listen for RPM change. you should have changed those gaskets at the oil pump if you had em off. that is the most likely culpret of the ticking noise. Quote Link to comment Share on other sites More sharing options...
robaru Posted May 30, 2004 Author Share Posted May 30, 2004 Thanks for the reply. Come to think of it, I may not have adjusted the pick-up coil base plate right. That is the plate that rotates with the vacume advance. And guess I'll put new gaskets on the oil pump. sure would have been easier to do it when the engine was out. Live and learn. Thanks again for the good advice. The fuel pressure was not running, and it was 3-4 psi. Quote Link to comment Share on other sites More sharing options...
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