Hello and help

[rocketscience]

Howdy, I've been using the forum for a couple years now but realized that I've never really introduced myself. My name is Britt, I live in Washington in the country south of Olympia but am currently picking morel mushrooms commercially in nw Montana. I grew up in Montana and lived in Boise, ID for 10 years. I do handyman type of work, am a musician and live/recording sound engineer and love camping, hiking, foraging, etc. I'm real interested in bushcrafty things.

I'm currently driving an 83 that I've put a ton of work into, along with the work the PO had done before I got it for $500. Recently named Tiger. I replaced all the rubber in the front end, the ball joints, tie rods, steering bushing and u-joint, suspension with a slight 1/2" spacer lift and Jeep Wrangler shocks and springs in the rear, it has a pretty new starter, alternator, rebuilt dizzy, recently replaced tune up parts, vac lines, fuel pump, front brakes, clutch, cv axles, have taken the transmission out and messed with it a couple times, have swapped the carb for one that came with the car with all good vac diaphrams, new rad cap and hoses, new thermostat and some body work... I think thats most of it. It needed a lot of work and I wanted to get it in as good of shape as I could all at the same time.

Onto the help part of the post, I've been having some drivability issues, mostly a randomly rough low idle, some hesitation on acceleration mostly when cold (just started a day or two ago) and some light colored smoke and raw gas smell from the exhaust when rough idling sometimes, I have only noticed it a few times. The rough low idle seems to occur more after slower town/mountain driving and never after highway driving and doens't seem to be temp dependent. Sometimes it idles worse after idling for a bit, sometimes better. I've checked for vac leaks but need to use carb cleaner, I'm going to do that tomorrow. I thought it was an electrical issue because when the symptoms first started I checked the ignition with my timing light and it wasn't firing everytime at idle on any wire (wires and plugs are new and look good). I cleaned the grounds and replaced the dizzy with my other rebuilt one which made the light flash everytime but didn't really help the problem. I started noticing the rough idle right after replacing the motor mounts and wondered if I'd pulled something too much or pinched the battery ground cable or something, I really really don't think so as I never noticed it even near the mount but I thought it was possible I replaced the fuel filter to no avail. I'm thinking its a carb problem and disconnected the aap for troubleshooting, would this make it hesitate? Robert previously suggested I take the top off the carb and clean it out when I was having warm start problems which I still sometimes am, but I've read on here that is pretty common, though I do plan to clean it out tomorrow or the next day when I change the oil. Any other pointers? Accelerator pump? Does the EBCV effect idle? Timing is at 10 btdc, compression on all cylinders is at 180, it runs cool, uses zero coolant and I have pressure and sniff tested the cooling system so I really don't thing the white/grey smoke is coolant.

I'm pretty inexperienced with carbs and gas fuel delivery, my other car is/was (still need to sell it) a VW TDI Passat wagon. Any thoughts? Thanks so much in advance for any help you can give me.

Edit: Also, something I forgot to say in my original post is that this forum is great, I've found so much useful information from mechanical stuff to keeping mice out and the dialog is always constructive and pleasant, its really refreshing.

DSC00754 by Britton Glenn, on Flickr

DSC00757 by Britton Glenn, on Flickr

DSC00756 by Britton Glenn, on Flickr

20180329_172526 by Britton Glenn, on Flickr

20180521_175701 by Britton Glenn, on Flickr

[Petros]

sounds like an intermittent minor vacuum leak. these would come form one of the vac operated items, like the EBCV, AAP, etc. Disabling the AAP would cause hesitation but only when cold, once it warms up a bit the TVSV is supposed to cut it out of the system. If it is warm and it hesitates when the AAP is disabled (capped off) than the problem is else where.

if you can not isolate the source of a vac leak, it might be the throttle shaft wearing out and allowing air to leak past the throttle shaft through the housing. Spray from carb cleaner at the throttle shaft end would reveal if that was the source. Unless it is bad enough to affect drivality, best thing to do is just idle it a bit higher, like 900-1000 rpm instead of factory spec. This is what I have done with most of the older cars I have owned, including several T4wd with this problem.

The fix, short of replacing the carb, is to have a machine shop counter bore the housing and install bushings that are drilled to the correct size. this is not an inexpensive option, so if it is that bad likely it is better to just replace it with one that is less worn. I think there are kits to install shaft seals in the housing, might be able to create a counter bore with a drill press and a vise.

It is possible you have a weak spark at low speeds. Personally I have had bad luck with reconditioned distributors, several times they were bad right out of the box for several different reasons. So you might do a check of the internal parts per the FSM procedures.

good luck.

[rocketscience]

Thank you for the insight, I have the idle set to around 900-1000 but when it idles low it gets real low, I think I hit 400 this morning. It does seem like a vac leak and I'll be sure to check the shaft and spray some cleaner around elsewhere to see if I can find anything else, I'm pretty sure the hoses are all good and routed correctly. I have to say that I'm impressed it'll idle down to 400! I remember you saying you'd had bad luck with the reman dizzys, I'll check it out too as per the fsm. I'm kicking myself for not bringing the original one that came with the car instead of bringing a spare reman, the yard here in Libby doesn't have anything similar but I know there is a Tercel and a Celica or two back in Helena where my folks live. I have a spare carb back in Washington if the shaft seems worn. Are there any other causes of weak spark? What are the possible effects of it running like this sometimes? Is unburnt fuel washing the oil off of the cylinder walls? Thanks again.

[Petros]

make sure the throttle dash pot linkage is adjusted properly. I forget the name, throttle opener or something, it is the device on the front side of the carb (faces front) with a little vac diaphragm and linkage. it prevents the throttle from slamming shut when you let off the throttle. it just slows the last 5-10 deg of throttle travel. odly if this is not adjusted correctly it will cause the idle to dip down too long right after letting off the throttle.

Also, there is as separate cold idle speed adjustment, if it is low idle when cold, you may need to set this higher. once it warms up this idle linkage lifts off the throttle shaft and it goes to the main idle stop with the larger screws adjustment on it.

too much unburnt fuel is not good for it, not to mention it is bad for economy and emissions. it will have extra fuel in the manifold when it is stone cold running, it runs extra rich on cold start up. but this should clear up as it warms up. only reason it would run rich after warm up is choke is not opening, or AAP is leaking fuel into the intake through the TVSV and the vac lines. or there is some rare internal problem, as in someone screwed up when they rebuilt it and there are missing internal checks or jets or something. That of course would only happen if someone rebuilt the carb (including buying a re-manufactured carb, that does not necessarily mean the carb was rebuilt properly, unfortunately).

[rocketscience]

I went through the tests in the FSM and the distributor tests out but if I pull a wire off of one of the plugs and hold it near the valve cover it won't jump any gap so I'm still thinking its weak spark. I did find corrosion on the contact on top of the coil going to the cap that I cleaned up as well as on the noise filter capacitor which I switched out but the car seems to be smoking worse now. Possibly related, the battery is only at 12.24 which seems kind of low, this was before doing cranking tests. Running the alternator is at 13.7. The car will start with only three plugs attached. I found vac leaks in my two new advance hoses which were a little too long and rubbing on stuff and leaks around the intake manifold, base of the carb and I think at the base of the port for the brake booster vac hose.

[rocketscience]

A little update... I ran the car a bit yesterday and adjusted the idle and throttle positioner, it was still putting out smoke, especially when reved and turned my new plugs black. I realized that I'm currently just above where the HAC activates and that I didn't have the vac hose for that hooked up, got that sorted out. I also just realized that the oil smells like gas and dumped it. I'm running synthetic and was about due for a change but was not happy about it, I need to get in the habit of smelling the dipstick and filler cap when i check. I don't know how long its been diluted but at least the level hadn't gone up. I know that running too rich and giving it gas on warm startups could cause this to some degree but that the fuel pump is a big suspect, is there a way to tell? I have a spare pump with me. I took the carb out today and am going to at least take the top off, clean it out and replace the needle seat tomorrow.

[rocketscience]

These are really more of repair questions so I started a new thread here viewtopic.php?f=4&t=13400