Victory then Defeat then

[Wew]

Gents,
I have put about 70 miles on the car. Usually fires right up now when I start it.
Last night went to start it up and it cranks, turns over and immediately dies.
Fresh full tank of gas with 15 miles on it.
New fuel accumulator and fuel filter were put on prior to any of this happening and again has about 70 miles of driving on it with these change outs.
Bumming because I ordered a complete front end rebuild from our host here and was really looking forward to working on other things on the car other than wrestling with starting issues again.
The other thing I notice is that is back fires sometimes when trying to start as well
Any recommendations appreciated.

Gary

[McLovin]

sound like some kind of vacuum leak

[everforward]

Try the simple things first. Replace the oxygen sensor relay below your passenger seat. Less than $15.00 and worth a try. It worked for me.

[wwest]

Originally Posted by Wew

Gents,
I have put about 70 miles on the car. Usually fires right up now when I start it.
Last night went to start it up and it cranks, turns over and immediately dies.
Fresh full tank of gas with 15 miles on it.
New fuel accumulator and fuel filter were put on prior to any of this happening and again has about 70 miles of driving on it with these change outs.
Bumming because I ordered a complete front end rebuild from our host here and was really looking forward to working on other things on the car other than wrestling with starting issues again.
The other thing I notice is that is back fires sometimes when trying to start as well
Any recommendations appreciated.

Gary

78...Backfires...? You now have a blown airbox.

[wwest]

Originally Posted by McLovin

sound like some kind of vacuum leak

Yes, a BIG one.

[E Sully]

If it has a pop off valve in the air box, check to see if the flapper is closed, and if the valve has come loose from the air box.

[vash]

backfire?

check the popoff valve. i bet you blew it off, or knocked it opened.

edit..assuming this is a CIS car.

tip. really helps to give helpful info like the type of car we are assisting with.

[Craig_D]

What year car is this?

[timmy2]

Originally Posted by vash

backfire?

check the popoff valve. i bet you blew it off, or knocked it opened.

edit..assuming this is a CIS car.

tip. really helps to give helpful info like the type of car we are assisting with.

+1, on the pop off as well as the other comment.
I know I've read and probably commented on some of your questions about your '78 SC that sat for 3 years.
Best to decribe all you have done when asking questions. Or better yet, stick to one thread that you ask questions in. Like Needspace's thread here:
1976 911S – from garage find to on the road
It helps everyone track what you've done and enables trouble shooting with knowledge.

Found it!
Maybe just ask more questions in this thread?
No time no start

[Wew]

Yes Timmy. You are my man up the coast. Yes air filter is baked. Nice big skid mark where the blow back valve opening is. Interesting on the low back cover that was installed it is not perfectly round bit the tip I'd squared off but still looks like it covers the opening.
P.s. the sucker fired right up for Mathis afternoon when I got home from work. When I killed it and tried to restart I had to let it crank in the start position for ten plus seconds and once it started to fully turn over I had to pump the pedal andrev it to keep it going. It wanted to die if I didn't keep my foot on the gas. I did mess with the timing again because it wouldn't turn over yesterday so I advanced it to closer to top dead center or potentially a scoatch after ( no timing light). Didn't help so moveditback to original spot Of course by eye. Then after I stalled it, lots of cranking to get it back. I am solo so I couldn't run back to time it on my own.
I have checked the aar and it is open when sitting cold.
There are vacuum hoses that go to the back of the motor that I can't see or have acces to. Any tricks or user friendly suggestions on how to change them out would be wonderful.
Sweet thing is that it doesn't seem to leak oil. Not a spot where I park it.
So
Hard start initially
Have to crank the starter for 10+ seconds before it will finally turn over.
Now when itstarts idle is low and if I don't give it gas or dies
There is some back firing during the starting

Thanks for any input or advice.

Gary
1978 911 sc cis stock. 186000 miles on the car. No history other than I am the third owner and it is a California targa and has lived in California it's whole life

[boyt911sc]

Gary,

All you need to do is put your car in neutral and turn the ignition switch. This is a fuel injection system and not carburator. So stepping on the gas pedal to prevent the engine from stalling is a sure sign of LEAN condition. It could be less fuel or too much air (unmetered) pick your choice. Hook up a pressure gauge and check your fuel pressures. Then test for air leaks. Stop guessing if you want to fix this problem. CIS troubleshooting is simple and easy.

If you don't have a fuel pressure gauge to use, it would be a very difficult way to start and look for the culprit/s. Test and confirm the absence of a significant source of vacuum leak and your engine will run as expected. Keep us posted.

Tony

[timmy2]

Gary,
Follow Tony's advice, he's a cis guru here.
Get a Bosch CIS injection test kit and learn how to use it. Then test your pressures.
Tons of information here on this site with everything you need to know.
Once you test, post the results and adjustment advice wll be given.
CIS Primer for the Porsche 911

[boyt911sc]

Originally Posted by timmy2

Gary,
Follow Tony's advice, he's a cis guru here.
Get a Bosch CIS injection test kit and learn how to use it. Then test your pressures.
Tons of information here on this site with everything you need to know.
Once you test, post the results and adjustment advice wll be given.
CIS Primer for the Porsche 911

Dennis,

This is not true!!!!! I'm just another DIY'er like you and the rest of the gang. While I have been very lucky in my CIS troubleshooting, I'm in no way an expert. I simply avoid guessing and have developed some simple tests to verify or confirm my suspicion.

Thank you for your vote of confidence on me. But there is a problem, people starts sending me emails and phone calls for assistance. I'm retired and very busy attending to CIS troubleshooting for other people which I enjoy every moment of it. I'm still searching for a CIS problem that could not be diagnosed correctly by DIY'ers. Troubleshooting is easy and fun.

Tony

[vash]

i'm in the east bay, in concord. i have CIS gauges..i've loaned them out before and didnt lose the tool (to a complete stranger)..

OP..your car sounds like my car did when i first got it. really really lean.

in my experience, on our cars; timing, mixture and idle speed all go hand in hand. like some sick menage a trois. you change one, you change the other three. my mechanic did it for me for $20. well worth the change IMHO.

i just didnt have the tools to do it right.

[timmy2]

Wew,
After reading Vash's post, I'm thinking there are a Pelican or two in the bay area that would be able to give you a hand. Probably willing to come over with the tools you need, and the hands on experience to get you running right. Just offer some lunch and refreshments and the pelicans should "flock" in.

I'm quite a way up the coast from you or I'd do it myself. (Although a 2-3 day trip down the 101 would be nice!)

[Wew]

You guys are awesome. Barbecue and all the beverage of your choice you could drink is always on the table. Truly! That shows roll and I rally appreciate all the advice and support everyone member of this forum has to offer. Looks like our hosts fuelressure ester is out of stock. There is a harbor freight 15 minutes down the road. Will this one work?

Master Fuel Injection Pressure Test Kit

[timmy2]

HF...Don't do it...
Here's one similar to mine:
S & G Tool Aid 33800 Injector Cleaning - Fuel System Tools

[Wew]

Cool. Thanks Dennis. Ordered!

[Wew]

How about fuel line for my cis. The ones I have on now are beat. Would like to change them all out.
Thanks
Gary

[timmy2]

Great to have the right tools. In my opinon HF is for consumables and one time use tools you have to have now!
You'll be using that gauge for many years to come.
Do some reading on how to test the system, by the time it arrives you'll have your fuel pump relay bypassed with a fused jumper, the wiring to the WUR off and ready to screw it in place to get your System and Cold control pressures.