SC opinion. Run towards or away.

[RMG001]

Found a nice driver 81 sc while visiting the local independent shop the other day. No rust good looking respray in original color. Interior; seats very good as they had sheepskin covers dash good no cracks. Carpet rough on the drivers side in the footwell. Tires around 35%. No rust,was able to inspect the underside while on the lift..

Agreed to 22500 while it was in the lift pending tune for poor performance.

The mechanic is a respected air cooled specialist well past his prime. So works slow and hardly ever. Drained fuel tank. Replaced fuel pump and plugs. Could not get performance issue figured out before owner got frustrated and picked up car.
Owner is chasing gremlins and changing parts but can't get it to run beyond an idle. Won't take throttle without bucking and backfiring.
Has agreed to reduce price 2500 if I accept as is. Very honest older enthusiast that is as frustrated as anyone would be.
Which way to run. Towards it or away from it.

[mreid]

run to it!

[Rawknees'Turbo]

Are you mechanically inclined, willing to learn, and/or have deep pockets in order to pay someone else (someone who knows what they are doing) to work on the car?

1982 911 models still have the K-Jetronic/CIS fuel stystem, correct? If so, the running symptoms you describe could be caused by any number of problems there (such as vacuum leaks, incorrect fuel pressures caused by a faulty WUR and/or problem with the fuel distributer, etc), and trouble shooting them is fairly difficult and very time consuming, so if you are willing and able, sorting out the running problems is doable, but if the repair(s) needs to be cheap and easy, then run from the car.

[creaturecat]

pig in a poke purchase. at this point.

[RMG001]

I had originally budgeted 25000 for a purchase. The 22500 seemed like a very good price from what I had seen. So baring anything catastrophic I have some backup in case I need it. Mechanically inclined. I have bought the Bentley manual and have read and re-read mist everything I can find on the CIS.
Understand that this can be a nightmare scenario. I read of people here who never get to the bottom of it.
So a pretty nice 81sc targa -starts- 20k. I thinks I'm in.

[bleek]

Originally Posted by Rawknees'Turbo

1982 911 models still have the K-Jetronic/CIS fuel stystem, correct? If so, the running symptoms you describe could be caused by any number of problems there (such as vacuum leaks, incorrect fuel pressures caused by a faulty WUR and/or problem with the fuel distributer, etc), and trouble shooting them is fairly difficult and very time consuming, so if you are willing and able, sorting out the running problems is doable, but if the repair(s) needs to be cheap and easy, then run from the car.

This! In my experience, CIS can be a real pain, even for really experienced techs to figure out as you and current owner can see. Once sorted, it's fine. Getting there is another story. Is there another tech you can take it to? Otherwise, slow process of elimination as Rawknees stated. As to whether to walk away, unless the car really speaks to you, there are other fish in the sea.

[RMG001]

Thanks Bleek. It is a nice car but I am trying to be unemotional about it. There is an upside if I figure it out. If not a real nightmare.. Maybe being too anxious. I go back and forth as you can tell

[SCadaddle]

If it only runs well enough to idle and won't accelerate, then that is a HUGE pig in a poke. I would ask for previous work documents that could be verified. At a minimum, if it hasn't at least had a top end build and lower head stud replacement you'd be wise to spend $30 for a valve cover gasket kit and remove the lower valve covers to see if it has any broken and or missing head studs. Your $2500 repair budget would increase by a factor of 3 or 4. should there be problems with the studs. With what you know now, I would tread lightly at best. And yes, I own an 82SC coupe.

[Rawknees'Turbo]

RMG,

This very old-school video is a must see for people new to CIS and who want to learn about it; it gives excellent, simplified descriptions of the components and what their roles are.

https://youtu.be/a4fJAfXYxWk

One thing for sure is getting familiar with the terminologies associated with K-Jet will really help you ask questions that the very experienced, CIS folks who are active in the 911 forum will understand.

Eight-ten years ago, I knew almost nothing of CIS, but had a mechanical background, so by reading, and putting my hands on the components, have really learned a lot about the system and can competently troubleshoot problems (no expert, like some in the 911 forum, by any means). I "had" to learn CIS in order to own the car that I do, as I would not be able to pay a shop to work on it. The point is, there is no black magic or soul selling involved.

[RMG001]

rawknees I have watched that video a couple of times. Very helpful. The ol mechanic who lets me hang at his shop and ask questions (never go empty handed, cup of coffee or cold drink.) has an engine sitting on a stand so I can look at all of the components. Like Scaddadle says if there is head stud or valve issues I am going to be knee deep into it. The ol mechanic does not suspect this an he has been around the car. But at 170000 miles it could be.
Condition of the sale was going to be a compression test.
Thanks for all of the comments. Breaks up the Bentley manual reading. Thing is heavy when you are trying to read in bed!

[SCadaddle]

An 81SC with 170k miles and never had a top end build, I should think there are several others that would back me up on the opinion that at a minimum, the exhaust valve guides are toast. Probably a terrible analogy, but I think that your focus on the CIS at this point is akin to an automobile crash patient with a broken neck and a broken arm---and you are looking at the arm first. Realize this advice is coming from someone that bought an 82SC at a price point that IF it had unknown head stud problems (had great compression numbers but didn't remove the lower valve covers and inspect studs) I still had money in the budget to spend another 10k and not be upside down in the market. I threw the dice. I lost. Spent the 10k on the engine. I'm ok with it. Question to you, would you be comfortable, with the little you know about the car right now, to have more than 30k in it?

[RMG001]

Originally Posted by SCadaddle

An 81SC with 170k miles and never had a top end build, I should think there are several others that would back me up on the opinion that at a minimum, the exhaust valve guides are toast. Probably a terrible analogy, but I think that your focus on the CIS at this point is akin to an automobile crash patient with a broken neck and a broken arm---and you are looking at the arm first. Realize this advice is coming from someone that bought an 82SC at a price point that IF it had unknown head stud problems (had great compression numbers but didn't remove the lower valve covers and inspect studs) I still had money in the budget to spend another 10k and not be upside down in the market. I threw the dice. I lost. Spent the 10k on the engine. I'm ok with it. Question to you, would you be comfortable, with the little you know about the car right now, to have more than 30k in it?

Nope! Would rather find a well documented 30k car they are out there. Problem is the 30k is a stretch or I wouldn't be looking at this option.

[bleek]

I agree that given the current symptoms and mileage, you're looking at quite a bit of dough to make right and make her good for the next 100k miles as opposed to band aid fixes. As Scdaddle says, go in with open eyes and expect the worst. That way, you can be surprised the other way if it ends up being better than expected.

[pmax]

Originally Posted by RMG001

Nope! Would rather find a well documented 30k car they are out there. Problem is the 30k is a stretch or I wouldn't be looking at this option.

The well documented 30K car is no guarantee that you won't be spending another $10k in the next thousand miles either. Given 30K is already a stretch now, this might not be the right kind of cars for you. Just saying.

So run away.

[RMG001]

Originally Posted by pmax

The well documented 30K car is no guarantee that you won't be spending another $10k in the next thousand miles either. Given 30K is already a stretch now, this might not be the right kind of cars for you. Just saying.

So run away.

Yep you might be right.

[RMG001]

SC Bentley Manual. Like new condition. Best offer.

[pmax]

Originally Posted by RMG001

SC Bentley Manual. Like new condition. Best offer.

However .... you can budget quite a bit less for the maintenance and parts cost of ownership if you can do everything yourself so consider hanging on to that manual.

[SCadaddle]

Originally Posted by RMG001

SC Bentley Manual. Like new condition. Best offer.

Nah, you can't give up that quick. Do some more research on the one you are looking at. Ask for documents. Find out if it has had a top end build and the studs replaced with steel or aftermarket studs. Spend the $30 for a valve cover gasket kit and an hour or so of labor with the old guy if there is any indication that you might be surprised. And if it doesn't fit the bill then keep looking. They are out there. In the meantime, keep researching what goes wrong with these cars and what it costs to fix it.

And I'll add one more tip about the car you are looking at-----if it is an 81SC and it is indicating 170k on the odometer, chances are a US destined 81SC had an 85 mph speedometer. If it doesn't then that's another paper trail you should research.

[Rawknees'Turbo]

^^^

Exactly - have the head studs inspected and ask the owner about the engine's oil consumption rate (only way to judge valve guides - compression and leakdown numbers won't indicate guide problems unless the wear is so bad that the valve doesn't seat correctly . . . not to mention that neither test is going to tell you much about the studs if the engine has not been run hard and up to temperature prior to the tests), before throwing in the towel.

[blau911]

Originally Posted by RMG001

Owner is chasing gremlins and changing parts but can't get it to run beyond an idle. Won't take throttle without bucking and backfiring.

Some of you guys are talking valves, head studs etc. While they may also be an issue, it seems pretty clear that if the car can't run above idle (900-1100 rev's), then the problem is with the fuel injection or even perhaps the distributor. An SC motor with a bad valve or broken head stud will still accelerate beyond idle albeit with less power, leak oil and blow smoke...