I have an 86 GT Sunbird non-turbo. Its running like poo, and I am trying to check my timing. When I disconnect the four wire connector, the car will not start at all. With it running the timing is very retarded. Like barely on the timing tab, and the distributor is almost all the way to the right. So is it ignition control module? I tested the pick up coil per the Chilton manual and its good. Fuel pump, filter and fuel pressure regulator were replaced last week. I got this car a few weeks back and it hasnt ran right since then. I did take the cap off and made sure the distributor was firing on number 1 just in case. It does need new plugs, cap and rotor, but that should not affect the timing.
Before I ask too much let me ask these questions.1st did the car run prior to Any work being done to it?2nd why replace the fuel pump and related items?I do not want to over load you with too much information until I know how the car prior to any work done.Please elaborate how the car ran prior to anything done as this can narrow down the issue.As a 1st gen guy for over 19 years I know a touch but not everything,as my fellow members know a touch as well!!!!! The more details on the prior situation before anything was done is crucial as this in my thoughts can narrow the problem.I will say removing the 4 pin est plug is (bull) you actually should have a single pin plug on rhs close to the cowl with a tan/white wire that has to be unplugged when timing .Things you could add are the engine you have specific like a 1.8 or 2.0 .Granted if it is a a over head cam or over valve engine will not matter on how to time it.
Fuel pump was replaced because the rubber piece between the pump and hanger broke. So I went ahead and put all new parts in since I had the tank down. Car ran but not well when I got it. Some stuttering going down the road at 55-60, and a few backfire through the intake at low speed when accelerating. I had thought of replacing the injector, but was going back to basics with timing first. The way it runs points me to timing issue, and the fact that even with the 4 plug connected the timing isnt correct, helps confirm that. It is the 1.8 motor, with 200k on the short block and about 10k on a rebuilt head. From what I can tell this motor does not have a knock sensor that I can see, and the book doesnt show one. Engine light isnt on, but I am working on getting a scanner that may work on it.
Before we get into the timing let's keep things simple.Granted the back firing could point to timing with the est plug in place and using a timing light.However some suggestions are to follow.1 remove the air cleaner and look at how the single injector spray pattern is.It should not be doing any of these ideas,dribbling fuel,and or dumping fuel it should have a Fine spray pattern like a spray bottle.2nd the backfiring could be a blocked up cat convertor ( I would look at how old this part is) as this CAN create a blockage and make the car run like crap.3rd on your egr valve it should have a vacuum line and just unhook that to see IF it clears up the running problem.Granted on a 86 gm could have changed from a vacuum hose to electrical plug soley to the egr so (just look at your egr to verify).I will not rule out a old worn out cat convertor and even the muffler are reducing air flow which will make the car run horrible.If the CEL was on a sensor would indicate that and I doubt you have any codes really!!!!I will say the timing could be off and make it back fire,however IF the car has a really old cat and or muffler this Could make the car run bad/and or act like the timing is not correct due to restricted air flow.Tired I am and done for now.We can get this sorted.
Random simple addition, but all the OHCs I've had have an alignment mark scribed/punched on the top of the distributor to align it to the cam carrier to where the timing was set originally. That will get you close, but maybe you don't have that - you probably would have noticed it. Also may want to consider your timing belt is aligned correctly?
Ron - can you describe where the advance bypass plug is and what it looks like more please? I've wondered about this before also because the Haynes says to pull the 4 pin plug which, as in original post, isn't right.
• 86 Skyhawk wagon : 2.0SOHC swap, Megasquirt, 20SEH cam
• 93 Sunbird sedan : 2.0SOHC, Microsquirt, ported head, 10:1
• 88 Sunbird coupe : 2.0SOHC, turbo project car, giant tires
Cat and muffler is fine. I have aligned the distributor by the marks still has the problem. I have thought about the timing belt being off by a tooth, but I am not sure if it would even run. So let me ask this. The marks on the timing tab are not readable, so my mark on the hub is on at the edge of the left hand side of the tab. Maybe I am wrong, and thats advanced? I see the tube on the right side of the tab and assumed thats the target for the timing mark, but maybe thats wrong also? The injector is spraying a mist, no dribbles or drips. Ill check the Egr this evening. I did double check that all vacum lines were good and connected. Thanks!
Shane let me ponder this a touch.As I have a OHV 2.0 the distributor set up is different.Drive a 5 I will try to snap a picture and dig into my chiltons and see if I can scan the info in and paste it here maybe over the weekend.I will say when I timed my car I soley unhooked that plug Not the est as the Haynes said.Kooky I know.But my car runs fine the way I did it.Also on the 2.0 ohv there are no marks for the distributor hole you have to scribe them in yourself.The 1.8 and 2.0 are very different in there own way.Plus I am cooked from ride mowing and actually got red but no sunburn.
Ok, so I cleaned off the timing tab enough to see that the left side of the notch is BTDC and the timing is fine. Still dont understand why it wont run with the ets unplugged. So I had unplugged the TPS and it ran better but high idle. Plugged it back in and car runs more like it should. Went ahead and replaced the plugs, cap and rotor, wires are fine. Runs good, but not great. Going to replace the TPS, clean the egr and replace the thermostat. Car will warm up to operating temp sitting and idling, but not driving down the road. Thanks for the help.
Def tired I am.I might share some ideas later as I have not felt too good today.Short yes but when one is yucky feeling the post are short.
