Frank T Posted July 14, 2013 Share Posted July 14, 2013 1987 GL10 single port fuel injected Non turbo Automatic 2wd 55K original miles I changed the MAF sensor a few days ago (due to non starting). When I got the car started I noticed it was idling rough and even stalled when I put it in gear. So I pulled all the plug wires one at a time (engine running) and when I pull cylinders 2,3 and 4 the engine runs worse. But when I pull #1 wire the engine has no change. So I changed the #1 plug, wires, distributor cap and rotor and pulled #1... still dead. I took the #1 wire off, put the old plug in the end of the wire and ran a jumper wire from the old plug to the new plug (still in the engine) and the old plug (exposed) fires the plug consistantly. I took the new plug out of the engine and the cylinder has good compression... Which tells me there is fuel issue, but with the single point fuel injection why would it feed all the cylinders except #1???? When in park it idles around 700-800 rpm. In drive it idles around 500-600. Any ideas why the #1 cylinder is not firing or why the engine is suddonly running rough? Thanks Frank T Link to comment Share on other sites More sharing options...
djellum Posted July 14, 2013 Share Posted July 14, 2013 id say the missfire would be number 1 as to why its running rough. leaky intake gaskets can kill a cylindar and weaken the others, and of course if your vavles aren't opening correctly you can have compression but no intake charge as well. the SPFI still pulses fuel, but i dont know if it pulses for each cylindar individually or if it just pulses at a rate for the RPM's. I dont really know off hand what is the most likely, but i would probably check the intake gaskets Link to comment Share on other sites More sharing options...
91 subaru Posted July 14, 2013 Share Posted July 14, 2013 +1 on the valves. I had that same problem on my car(carbed) i took the valve covers off and adjusted the valves. Problem solved. Link to comment Share on other sites More sharing options...
john in KY Posted July 14, 2013 Share Posted July 14, 2013 Had the same problem once. In my case the problem turned out to be a small broken vacuum line that was attached to the intake manifold runner that fed the dead cylinder. Link to comment Share on other sites More sharing options...
MilesFox Posted July 14, 2013 Share Posted July 14, 2013 87 GL-10 would be mpfi with 4 injectors. maybe your car is an 86? Link to comment Share on other sites More sharing options...
Gloyale Posted July 14, 2013 Share Posted July 14, 2013 +1 on the valves. I had that same problem on my car(carbed) i took the valve covers off and adjusted the valves. Problem solved. Ea82 engines do not have adjustable vavles 1 Link to comment Share on other sites More sharing options...
Gloyale Posted July 14, 2013 Share Posted July 14, 2013 87 GL-10 would be mpfi with 4 injectors. maybe your car is an 86? Nope. Non-turbo MPFI was dropped for the GL-10 in 87. All 2wd non-turbo cars that year are SPFI (excluding XT) 86 2wd non-turbo GL-10 would also be SPFI 85 2wd Non-turbo GL-10 would be MPFI 85 4wd Non-turbo GL-10 would be carbed He's got an SPFI car. My suggestion would be to do a leakdown, not just a compression check. Burnt or hung up valve can still show pretty good compression. Link to comment Share on other sites More sharing options...
Frank T Posted July 15, 2013 Author Share Posted July 15, 2013 (edited) I found a very small vacuum hose disconnected on the same side as the #1 cylinder!!! I Hooked it up and it smoothed out the idle. Why this was acting like the #1 cylinder not firing??? Im assuming it was pulling vacuum from near the #1 cylinder/// Im just glad it was something simple. Thanks for everyone's input!! Edited July 15, 2013 by Frank T Link to comment Share on other sites More sharing options...
91 subaru Posted July 15, 2013 Share Posted July 15, 2013 Glad you got it figured out. Good to know theres no adjustment on the valves and kinda weird also Link to comment Share on other sites More sharing options...
naru Posted July 16, 2013 Share Posted July 16, 2013 I found a very small vacuum hose disconnected on the same side as the #1 cylinder!!! I Hooked it up and it smoothed out the idle. Why this was acting like the #1 cylinder not firing??? Im assuming it was pulling vacuum from near the #1 cylinder/// Im just glad it was something simple. Thanks for everyone's input!! Because #1 was not firing. Vacuum leak leaned out the mixture for #1 to the point of incumbustibility Link to comment Share on other sites More sharing options...
stichn56 Posted August 27, 2013 Share Posted August 27, 2013 Because #1 was not firing. Vacuum leak leaned out the mixture for #1 to the point of incumbustibility these engines aren't very powerful anyway. when even a small vacuum leak can feel like a cyl's not firing. Link to comment Share on other sites More sharing options...
leniac Posted August 27, 2013 Share Posted August 27, 2013 post a pic o the vacuum hose... for the future problems.... Link to comment Share on other sites More sharing options...
ivans imports Posted August 27, 2013 Share Posted August 27, 2013 stuck injector try a differnt one have seen them stick faily often Link to comment Share on other sites More sharing options...
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