Engine Problem Need Help April 17, 2012, 08:40:11 PM Hello,I have an 88 XR7 with 133k miles. The engine is stock with no mods.It started to run rough and miss, I replace the plugs, wires, cap and rotor. Same problem. I pulled the plugs and notice that cylinders 1 and 2 the plugs were totally black and dry. The rest were black with a white area. White like brand new white. I did a compression test, most cylinder were around 150 except for cylinder 5, it was 90. I also noticed that when I put my timing light on cylinders 1 and 2 that the strobe was erratic indicating to me that the cylinders were not firing all of the time. The rest of the cylinders were fine, including number 5, whose compression was only 90. I'm thinking that I may have a couple of problems, low compression on one cylinder and two cylinders not firing properly. Am I looking at a valve job? It does not blow any smoke and it uses a quart of oil every 1000 miles. I'm thinking the bottom end is ok.Any suggestions would be appreciated,thanks,Lou Quote Selected
Engine Problem Need Help Reply #1 – April 17, 2012, 09:32:00 PM Run codes, see what comes up. Quote Selected
Engine Problem Need Help Reply #2 – April 23, 2012, 10:31:34 PM Unfortunately, OBD1 does not give misfire codes so getting codes will not be helpful Quote Selected
Engine Problem Need Help Reply #3 – April 23, 2012, 11:49:57 PM This is pre obd1, it is evc-4. You can run codes, and not only can you tell if its an injector, you can tell what bank has the misfire, if it is fuel or spark, and perform an engine cylinder ballance test that will tell you which cylinder has the problem. The tfi module also controls the spark with relation to the pip in the dist, and all of these have co-relating codes that can help pin point the problem. The system is also so well known that almost any problem can be trouble shot or fixed within minutes once you learn what to look for. The codes are also split into three very specifiy catagories making it even easier to troubleshoot and find the problem. There is continous memory, koeo(key on engine off) and koer(key on engine running) as well as the cylinder ballance test. It will also save you a lot of time and frustration.So before wasting more time and energy, check out this lik explaining how to run codes and what to look for, then we will go from there. http://sbftech.com/index.php/topic,2471.0.htmlObd 1 and 2 have more in common with evc-4 then almost any other system. Let us know what pops up and what else we can help you with. Quote Selected
Engine Problem Need Help Reply #4 – April 24, 2012, 03:28:51 AM Quote from: Haystack;387632This is pre obd1, it is evc-4. You can run codes, and not only can you tell if its an injector, you can tell what bank has the misfire, if it is fuel or spark, and perform an engine cylinder ballance test that will tell you which cylinder has the problem. The tfi module also controls the spark with relation to the pip in the dist, and all of these have co-relating codes that can help pin point the problem. The system is also so well known that almost any problem can be trouble shot or fixed within minutes once you learn what to look for. The codes are also split into three very specifiy catagories making it even easier to troubleshoot and find the problem. There is continous memory, koeo(key on engine off) and koer(key on engine running) as well as the cylinder ballance test. It will also save you a lot of time and frustration.So before wasting more time and energy, check out this lik explaining how to run codes and what to look for, then we will go from there. http://sbftech.com/index.php/topic,2471.0.htmlObd 1 and 2 have more in common with evc-4 then almost any other system. Let us know what pops up and what else we can help you with. +1 Quote Selected
Engine Problem Need Help Reply #5 – May 01, 2012, 08:09:50 PM Thank you for the information I'll check it out and get back.thanks again. Quote Selected
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