High Hydrocarbons / deq and idle issues!!

[duster97]

Which port on th e charcoal canister do I hook up to the egr port on the weber?

[duster97]

So I did a compression test and it's not looking too good.

1st is at 150
2nd is at l20
3rd is at 130
And 4th is at 90

What's the next step? Pulling the motor and putting new rings in, or could it be valve guides and seals?

[irowiki]

Might be the headgasket too!

[duster97]

The oil isn't slimy, no overheating and no coolant leaking though I've put 3000 miles on this thing since I bought it

[Petros]

worn rings will not cause that, they tend to wear evenly. The rings are likely in good condition. A bad exhaust valve in #4 and going bad in #2, will do that however. pull the head and replace all of the exhaust valves (they do not cost much), with new valve stem seals. Lap the valves into the old seat with lapping compound, you keep that up until you get an even and clean seat all the way around. Clean all the carbon off the piston tops and that should even out the compression issue. You can to this repair for less than $100 worth of parts, though it is a big job and you will need a valve spring compressor and a good quality torque wrench. New head gasket, perhaps an exhaust flange head pipe gasket, and by pass tube o-rings, plus valve stem seals and 4 new exhaust valves.

do not bother regrinding the exhaust valves, replacement them with new ones. Once they get over heated it is only a matter of time before they break off and wreck the engine.

on the plus side, doing this job (it will take you better part of a weekend, could be done on a saturday if you have all the parts and tools you need), should solve the issues, make it run stronger and smoother, and improve the fuel economy.

[dlb]

if you clean the dust and dirt off the top of the charcoal can, you should see each port has raised letters by the base. the outlet should go to the carb.

before doing any engine work, you should do a leak down test and add a small amount of oil to each cylinder before retesting the compression. use a bulb syringe to squirt the oil in each cylinder, just a teaspoon or so. if it comes up considerably it usually indicates worn rings.

if it does appear to be the rings (which i think it looks like since all the cylinder are fairly low, #4 is just worse that the others),i would add seafoam to the oil, run it for a few hundred miles, then change the oil and add a can of 'restore' to it. i have had good results with it increasing compression considerably.

when you did the initial test, was the engine warm, all plugs removed, throttle wide open? those are 3 important details for to make a compression test as accurate as possible.

[duster97]

I work really long weeks building cabinets, so this weekend I'm going to try the sea foam and restore and see if that brings it back up. If it doesn't then I'll get a Leak down test kit and identify where my loss is coming from. I hoping it's not the rings and just a couple valves. I was thinking if I need to rebuild the head I might as well get a remanufactured one complete with new valves and a cam. Alot of work in order to pass deq, but on the plus side the car will defiantly run much better once I get compression up to par again

[dlb]

for the leak down test, just use a regular compression tester, and steal the bulb syringe (aka turkey baster) from the kitchen, or buy one at the dollar store.

good luck!

[duster97]

By comes up considerably, you mean the compression after I squirt a teaspoon of oil in the clyinder?

[dlb]

that's correct. the theory is that if the rings/cylinders are worn, the oil will help temporarily seal them better and bring the compression up.

what i don't like about the leak down test is that adding anything to a cylinder, like oil, means decreased displacement in there, which will naturally bring the compression results up a bit. that's why i think it's important to add only a very small, consistent amount of oil to each cylinder. even then, the lead down test is just used as a general indication. but give it a try and see what you come up with.

[duster97]

So I did the leak down test. Added a little oil to each cylinder and the only difference was the number 4 cylinder went up from 80 to 90.

I also did the seafoam and restore additives. Still got low compression and what sounds like a small misfire. Plugs and wires are good. Head gasket is good. No blue smoke or coolant leaks, no over heating. Valve problems perhaps?

[duster97]

I think I may have fixed my problems. Turns out my valves were way over tightened. I adjusted them per the fsm guideline and now it's running like a whole new car. No more misfire. Now when I unplug the 4th spark plug wire there is a noticeable difference. Once deq is open I'll run it through for the real test. Wish me luck

[dlb]

good for you. what is the compression now?

[duster97]

I'm gonna re do the compression test and get a timing light and reset the timing tomorrow. I got to go pick up my girlfriend from work, plus it's like 97 degrees in portland right now and I'm all sorts of sunburnt on my back from working on the tercel all morning gonna take a break for the rest of the evening. I'll report my results tomorrow

[duster97]

I just did another compression test and here's what I got.

Number 1 155
Number 2 115
Number 3 120
Number 4 120

About the same for 1 thru 3 from my last test. Number 4 went up 40 psi. Still on the lower end all around tho.