CIS Problems - Test Gauge recommendations - 1980sc running rough

[nicfranc]

Time for me to climb the CIS learning curve.
Have read Jim's CIS Primer, CIS for Dummies (tirwin) and also have read Tony's (boyt911sc) threads. Thanks guys for posting so much content.

Question:
Is there a CIS Gauge Testing Set that anyone can recommend or prefers ?

My US 1980sc has been running great until this week.
My car has its Original unopened Engine with 300,000 miles

I left it out in the heat and did not drive it for a 8 days.
When I started it this weekend it ran very rough and coughed through the exhaust at low revs.
It barely idles without stalling and now when I remove the oil cap it stalls completely which it never did before.

The car runs well at high revs and at high speed but it is bogging down in first and second.
Unfortunately I can't be driving around town doing 80 all the time ;-)

My first task will be to eliminate potential vacuum leaks as you all recommend. I am prepared to do a partial engine drop to replace as many hoses as I can reach. I would like to put off pulling the Engine till the winter.

Rotor, cap, plugs are new and Valves are adjusted distributor has been timed 5 Deg. BTC
No broken head studs.
Air Box is good and there is no Pop-Off Valve
Cat has been deleted and there is no O2 sensor
Relay under passenger seat has been replaced.
Original Engine with 300,000 miles

I have not inspected WUR (need Gauges)
I have a new fuel filter from Pelican that I can install but was wondering if I should replace the screen on the bottom of the gas tank first.





Noticed this kinked breather hose.
But I do not think it is the cause of the rough running.

[Bob Kontak]

Consider buying Charles Probst's Bosch fuel injection book. It goes into theory deeper than the other sources but still is geared towards the laymen.

Buy the set from Pelican. It's a (very) few more dollars than the Harbor Freight kit but from threads I have read it is of better quality.

Did you do any work before the eight day rest? Just getting at sometimes the last things you do can have created problems. Hose bumped off, etc.

O2 sensor is pretty important. Cat is not. No O2 sensor sensor will not allow the frequency valve to operate in closed loop mode. You are running in open loop now and you will not derive all the benefits (e.g., fuel economy) the system provides.

As a starting point for assurance, make sure your O2system/Lambda fuse is not fried. If it is toast, the function of the Lambda relay that was replaced will be negated. If that system has no power, it will operate in "loopy" loop mode which means horrible. Very poor throttle response. You can limp the car around but it is more of a "gimp" than a limp.

A favor please. The kinked breather hose. Where does it connect? On my 81 there is a hose like that which connects to the charcoal canister. It connects to the side that has the small hose exiting the canister which is closer to the firewall and not the rear bumper side. Any way you can post a pic of where the end connects? You may have it on the wrong port but can't tell from pic.

[nicfranc]

Originally Posted by Bob Kontak

Consider buying Charles Probst's Bosch fuel injection book. It goes into theory deeper than the other sources but still is geared towards the laymen.

Buy the set from Pelican. It's a (very) few more dollars than the Harbor Freight kit but from threads I have read it is of better quality.

Did you do any work before the eight day rest? Just getting at sometimes the last things you do can have created problems. Hose bumped off, etc.

O2 sensor is pretty important. Cat is not. No O2 sensor sensor will not allow the frequency valve to operate in closed loop mode. You are running in open loop now and you will not derive all the benefits (e.g., fuel economy) the system provides.

As a starting point for assurance, make sure your O2system/Lambda fuse is not fried. If it is toast, the function of the Lambda relay that was replaced will be negated. If that system has no power, it will operate in "loopy" loop mode which means horrible. Very poor throttle response. You can limp the car around but it is more of a "gimp" than a limp.

A favor please. The kinked breather hose. Where does it connect? On my 81 there is a hose like that which connects to the charcoal canister. It connects to the side that has the small hose exiting the canister which is closer to the firewall and not the rear bumper side. Any way you can post a pic of where the end connects? You may have it on the wrong port but can't tell from pic.

Thank you Bob for the advice.
I will order the Book and the Gauges today.

I took some more photos of the braided hose.
I have a replacement that I purchased from Pelican and I believe it connects from the Engine breather port to the lower hose connection going to the the oil tank by the filler tube.

I can't see how I can replace it without an engine drop or at least a partial drop.
It looks like someone spliced this braided hose which now has the kink in it. Perhaps it was his way of replacing half of the hose without removing the engine.

I also have discovered there is no restricter in the top tube that connects to the Oil Filler tube.

The charcoal canister does not have a hose in the rear facing the Oil Filler Tube.
It does have two braided hoses in the front of the canister. One is larger than the other.

Nick

Braided hose connected to oil tank.

[nicfranc]

I sprayed Carb Cleaner around the intake manifold area on both the left and right side of the engine and it smoothed right out and began to run perfectly.

Could the car sitting out in the hot sun for a week caused the intake gaskets to loosen and no longer seal ?

Is there a way to isolate where the leak is.
Right now it seams like there are multiple leaks.

[Bob Kontak]

Originally Posted by nicfranc

I sprayed Carb Cleaner around the intake manifold area on both the left and right side of the engine and it smoothed right out and began to run perfectly.

How sweet it is. You are halfway home.

Did it smooth out when you sprayed the air box side or the cylinder head side?

Breather hose is do-able with partial drop - pure hell but worth the scrapes. Been a while since I did it.

Your charcoal/carbon canister hook ups are ok. Thanks for that. The skinny line runs to the left front fender where you expansion tank for fuel overflow/vapor. The fat line runs behind engine and then to the driver's side of the air-box. 77 was the last year for the hose off the bumper side that plugged into the fan shroud over by # 1 cylinder. However, boyt911SC has this hose on his 78 so there may have been some leftover parts bleed over into the SC model.

[nicfranc]

[QUOTE=Bob Kontak;7574927]How sweet it is. You are halfway home.

Did it smooth out when you sprayed the air box side or the cylinder head side?

I am trying to narrow down the source of the leaks.
I am going to try using a propane torch to see if I can pin it down.

I noticed that the injectors wiggle a bit from side to side and they are a source of some of the leaks.

This is the first time I have left the car out so what might have happened the 33 year old materials expanded in the really hot weather we have been experiencing up here in Oyster Bay.

[Bob Kontak]

[QUOTE=nicfranc;7574996]

Originally Posted by Bob Kontak

I am trying to narrow down the source of the leaks.
I am going to try using a propane torch to see if I can pin it down.

Direct spray of the carb cleaner/starting fluid is pretty effective om a particular spot.

You will find it. Your o-rings are probably hard as rocks.

How hot was the car when you last drove it? Any oddball things that would have caused the engine temp to spike?

[boyt911sc]

Nicfranc,

It would take only a minute to do the engine vacuum leak tests with soapy water. Apply a continuous flow of air (low pressure). I had posted some pictures in a couple old posts. With the engine installed, you can't see the whole airbox specially the backside and underneath it. But with a good light source and a small mechanic mirror you would be able to peek at it.

With the system (engine) under air pressure (1-2 psi) just enough to inflate a latex glove would reveal all these hidden or unknown spots where leaks are presence. An air compressor even the portable ones could be used to inject air into the engine and plug the exit orifices/holes to keep the pressure positive. You'll be surprised how much air leak could be there even with a decent running CIS engines have at anytime.

PM me if you need further assistance. Test and confirm.

Tony

[nicfranc]

[QUOTE=Bob Kontak;7575053]

Originally Posted by nicfranc

Direct spray of the carb cleaner/starting fluid is pretty effective om a particular spot.

You will find it. Your o-rings are probably hard as rocks.

How hot was the car when you last drove it? Any oddball things that would have caused the engine temp to spike?

I had the car out in the direct sun and it was brutally hot and when I opened the engine compartment I noticed all the my wires were really flexible.
Before they were a bit stiff as the sheathing was brittle and dried out.

I started tightening up the leaks I could reach and am putting together an order for Pelican.

I got the car to run better but it is taking awhile to warm up and run without breaking
up. After ten minutes it was revving nicely. I put some techron in and will see if that helps.
Thanks for checking in.

[tirwin]

[QUOTE=nicfranc;7575697]

Originally Posted by Bob Kontak

I put some techron in and will see if that helps.

I was going to suggest to "burp it" as Joe Bob says with a can of BG44K but the Techron is probably just fine. (FWIW: I decided to start using the BG44K after reading a lot about it on here. I've got no personal data that says it's better or worse than Techron.)

[Bob Kontak]

Listen to Tony. The starting fluid trick is only great for macro leaks.

If you take the time to do the reverse leak test - the correct test - you pressurize your system - not too much - and spray soapy water on the suspect areas and they bubble out where the leaks are. Literally get kids bubble soap.

Now, the minute Tony speaks of is a "Tony minute" Give yourself an hour or two as you have to figure out what to seal off, etc. It's worth every second.

[ArchHibb]

nicfranc -

I just finished replacing the airbox in my 82 and have been researching CIS fuel pressure gauge kits. The kit from our host is listed as on backorder, so I may have to source one elsewhere. Just make sure whatever kit you get is CIS specific so that you get the correct fuel line fittings.

There's no way I could have tackled my project without invaluable help from the forum and especially Tony. (boyt911sc) I was on the phone with him just this past Saturday as he helped walk me through startup for the first time since getting everything back together. Thanks Tony!

That kinked braided breather hose connects to the breather cap (a.k.a. the "Trinity") on top of the engine directly beneath the airbox. The swivel fitting you see with the hose clamps is the correct factory setup. On my car, the hoses are smooth rubber, not braided. Sounds like you're well on your way to fixing some intake leaks. Assuming you replace your injector seats (2 o-rings and the plastic holder) you might clean your injectors while you have them out. There's a great DIY on how to do it yourself by billjam. Good luck!

[Bob Kontak]

Originally Posted by ArchHibb

Assuming you replace your injector seats (2 o-rings and the plastic holder)

[enzo1]

[Bob Kontak]

Words are so overrated.

Nice.

[RDM]

Originally Posted by bob kontak

words are so overrated.

+1

[nicfranc]

I ordered from Pelican injector sleeves and O rings and also ordered manifold gaskets and
intake rubber runner sleeves.
I am also replacing some breather hoses to the oil tank.

Are there any other common sources for vacuum leaks that I should check out ?

Interesting thing I have noticed is as the car heats up the vacuum leaks seam to dissipate a great deal. Is that the a common occurrence ?

Should I not be driving the car while I have these vacuum leaks ?

[Bob Kontak]

I think you can drive it without damage but others may know better.

Note how tight the nuts are on the intake runners where they bolt to the heads when you replace the gaskets.. If they are loose, it's a good source for leaks. #6 piston nuts are a bear to get to. 1/4" drive ratchet and some fancy swivel toys will help.

I remember putting grease on the injector o-rings. Not silicone based but something else. Also, HC based is no good either. I may have used lithium grease and I am not even sure that is correct.

The hose that runs from the drivers side of the engine to the vacuum booster for the brake master cylinder can cause fits. There are probably several ways to check it. John Walker has seen these hoses fail underneath the car.

My brass pipe that runs into the back of the throttle body (I think this ties into the brake booster hose) came loose from the back of the TB. I had to JB weld it back in and subsequently found I did not have the support bracket bolted down which was the root cause of the issue.

Anywhere on the airbox past the sensor plate.

I have seen the hose on the aux air valve slide off the snoot if the clamp is not reefed down enough.

The bubble test might be a good one BEFORE you disassemble. You can even use a shop vac in reverse if you do not have an air compressor.

Your breather access should be way easier with #3 and #6 intake runners removed.

May help to take the small blower fan and it's base off as well for breather access as well.

#6 intake runner nuts will be the biggest PITA of the job.

Nice work, BTW. Keep us posted.

[nicfranc]

Thanks Bob,

I have both big and small Compressors and Vacs.
I will give the bubble test a shot

The sudden onset of my engine running poorly makes be wonder if a hose came loose.
I will check for vacuum leaks where you recommended.

Nick

[Bob Kontak]

Sudden onset could be the O2 system blowing a fuse or the O2 relay going belly up.

Find the O2 system fuse and pull it while the car is idling. If there is a big "honkin" reduction in how it runs, put it back right away. :-)

If no change, gotta get into the O2 relay and pull that while idling.

Suspect it's not the issue and forgive me if this is a repeat.