# 86 gli, misfire at idle, bogging at low rpm, HELP



## i.lub.my.dub (Aug 24, 2007)

So here is the deal. 

1986 gli with CIS has been sitting about two years. 
Just replaced the inline fuel pump (its from the junkyard, previous owner lost the inline housing) the pump seems good, making no noise or whining. 
The in tank fuel pump seems to be good as well. 

Car has somewhat of a difficult time cold starting, once started it will misfire causing the motor to jerk. Once it is warmed up it isn't as bad. Smells like it is running rich, plugs look like it is running rich. At low rpms it seems to bog down while being driven and will misfire. 

With the climate control on the off setting, give it gas, rpms come up them fall to around 300rpm, sometimes the rpms come back up, sometimes the engine stalls. When the climate control is set on defrost, rpm at idle goes up to about 1100 and this no longer occurs. 

I have replaced the plugs, wires, and dist. cap as well. 

Any ideas?


----------



## WaterWheels (Aug 14, 2005)

A misfire or a bog are not the kind of things you can post up and get a fix for, OK once in a while someone might guess right and seem the hero, but you do indicate some things that need fixing or looking into. Being too rich can cause a miss in the engine, maybe it is not a true misfire, maybe your's isn't either, but it can cause a shake or jerk while the engine is running. The issue with the idle vs. the climate control indicates also the engine is on the rich side. The CIS-e system has a connection to the air conditioner, when turned on, it tells the idle stab valve to let in more air to keep the idle steady. In your case it seems the mixture is over rich and when the ISV lets in the extra air, the idle increases due to the mixture becomming better. I would look into why the mixture is too rich and fix that first (DPR test harness and multi-meter and/or exhaust gas anylizer). Also check/test all the ignition parts, wires, plugs, coil, etc., the values should be in any good repair manual. With the ignition system in good shape and the mixture set right, you will have at least a base-line if the problem did not vanish.


----------



## 88azur (Apr 20, 2010)

i would assume you have air conditioning in your car.when the defrost switch is activated the idle boost switches on in conjunction with the compressor. you said the idle will fluctuate sometime when off as well. there is also another idle boost valve that reacts to idle speed drop. the relay for this one is on top of the fuse panel. sounds like you need to reset the idle speed first, then attempt to adjust the fuel mixture. pull the realy and see if it rusted up. all the vw's i have owned have all seemed to have wet fuse panels at sometime or another


----------



## dangerkart (Jul 12, 2010)

i have a non a/c car and am kind of having this same problem. it sounds like it is pre-firing at start up, and jerks the engine. when it starts and is running it's smooth as can be though. it smells like it could be running rich but i know this isn't the only problem.


----------

