Do I have a Fuel Problem?

[arbita1]

I think my troubles may be fuel related.

The engine starts, however this morning after it sat overnight I had to press the throttle a few times to get it to start the first time. Once started it idles at 1,200 for a second and then the rpms begin to drop until it stalls out. Pressing the throttle while the rpms are dropping does not help and the engine continues to drop and stall regardless.

I'm ruling out an ignition problem because the engine starts (am I incorrect to assume this?).

When I turn the key to the ON position I can hear the buzzing of the fuel pump from the front. The fuel pump fuse is fine. I checked for battery power at the relay and that is fine too. I have also done the check on the fuel distributor by pushing the plunger up from the air box. I heard the screaming sound when I did that.

However, I did notice there seemed to be some fuel in the air box. Does this lead to any ideas?

I think my next move might be to check the fuel pressure, but I don't have a CIS tester, so I may have to order one first before I can move on. Unless someone has another idea of what this may be.

[Scott R]

Originally Posted by arbita1

I think my troubles may be fuel related.

The engine starts, however this morning after it sat overnight I had to press the throttle a few times to get it to start the first time. Once started it idles at 1,200 for a second and then the rpms begin to drop until it stalls out. Pressing the throttle while the rpms are dropping does not help and the engine continues to drop and stall regardless.

I'm ruling out an ignition problem because the engine starts (am I incorrect to assume this?).

When I turn the key to the ON position I can hear the buzzing of the fuel pump from the front. The fuel pump fuse is fine. I checked for battery power at the relay and that is fine too. I have also done the check on the fuel distributor by pushing the plunger up from the air box. I heard the screaming sound when I did that.

However, I did notice there seemed to be some fuel in the air box. Does this lead to any ideas?

I think my next move might be to check the fuel pressure, but I don't have a CIS tester, so I may have to order one first before I can move on. Unless someone has another idea of what this may be.

OK, for starters the fuel pump does not come on with the key, it comes on when go from on to start and stays running while the sensor plate is lifted. I'm not saying you don't have a bad pump, but it should not be on with the key.

[boyt911sc]

Matt,

By just reading your post, I detected two (2) anomalies that have to be corrected. The first one is the fuel pump. It should not be running when you turned the ignition switch on. And secondly, CIS does not need any help from the accelerator to be able to start.

CIS troubleshooting without a fuel pressure gauge will involve a lot of guess work. Using trial and error method to locate your problem will cost you a lot of time and money including some aggravations. You could test suspected CIS component like WUR, AAR, CSV, FD, FP, injectors, and even do a vacuum test without running the engine.

Not being able to check your cold control and system pressures at this point is a big disadvantage or set-back in trouble shooting your engine's problem. Keep us posted.

Tony

[81white911]

Sounds like the beginnings of the problems I experienced this summer which lead to the engine completely quitting. Get the cis-k tester from JC Whitney and a multi meter, (volts, ohms, condutivity from your local store). The guys online here have all the pressure data to help you pinpoint your problem. I had to clean a small screen in the warm up regulator. you can follow the threads under 81 cis-k fuel test

[arbita1]

I'm going to order the fuel tester today. The one from JC Whitney is a 2-3 week lead time. So I might have to spend a bit extra and get one from somewhere else.

In regards to the fuel pump, are you saying that I should not hear a buzzing noise from the front when I turn the ignition on?

I have noticed that I have a black relay in the fuel pump socket...not the red one. Could that make a difference?

[T77911S]

is this a sudden problem or something that has been getting worse?
the first place to always start is with vacuum leaks. CIS is very sensitive (talk nice to it) to air leaks.
do you have a pop-off valve?
check the connector on the back of the fuel dist.(FD). if it was removed, the FP will run, like the PO did on my car and bypassed all that so the FP runs all the time.
since you raised the plate and then heard the screaming, i would assume the plunger is not stuck.
possible the cold start injector is staying on due to a bad TTS?

[arbita1]

Originally Posted by T77911S

is this a sudden problem or something that has been getting worse?
the first place to always start is with vacuum leaks. CIS is very sensitive (talk nice to it) to air leaks.
do you have a pop-off valve?
check the connector on the back of the fuel dist.(FD). if it was removed, the FP will run, like the PO did on my car and bypassed all that so the FP runs all the time.
since you raised the plate and then heard the screaming, i would assume the plunger is not stuck.
possible the cold start injector is staying on due to a bad TTS?

Let's put it this way...I have always had a cold start idle problem. It always idled very low until it warmed up. And then once warm it would idle on the high side. So no, it was never perfect. But I never had any stalling problems where I couldn't even get the engine to run.

I looked around the engine compartment for obvious signs of an air leak. No hoses were disconnected.

Yes, I do have the pop-off valve.

I'll check for the connector on the fuel distributor. TTS???...is that the thermo sensor? I'll check that too.

[arbita1]

I'm waiting for my fuel pressure tester to be delivered, but I decided to do some more checking tonight.

The engine is still starting with no problem. It will run for about a minute and then the idle will drop and it will struggle to stay alive until it stalls. Each time it stalls there is a pop in the air box (I have the pop-off valve) and I can smell fuel.

I tried enriching the mixture with the setting screw and I was able to keep the engine from stalling. However it was running very rough and every time I pressed the throttle the RPM's would drop and it will pop in the air box.

Does this shed any light on anything?

[T77911S]

i assume you are talking about the 3mm allen screw?
if so, it sounds like it is running lean as it warms. there is a screen at the input to the WUR that may be clogged, it would make it run very lean if it is.
TTS= thermo time switch. you could pull the connector on the cold start valve and see if makes a difference while running.
reading this again i sound like i am cotradicting myself lean-rich-lean???

[arbita1]

Originally Posted by T77911S

i assume you are talking about the 3mm allen screw?
if so, it sounds like it is running lean as it warms. there is a screen at the input to the WUR that may be clogged, it would make it run very lean if it is.
TTS= thermo time switch. you could pull the connector on the cold start valve and see if makes a difference while running.
reading this again i sound like i am cotradicting myself lean-rich-lean???

Yes, the 3mm allen screw adjustment.

I was just searching the board and found that the domelight/clock fuse also provides power to the Lambda brain.

Just prior to my problem, I was removing my interior dome light because it was stuck and I wanted to see if it could be fixed or needed to be replaced. Upon putting it back in I got a spark. It's possible that I could have blown the fuse when it sparked. I didn't think anything of it at the time.

Could this be it???

UPDATE...

I just had my wife go out and look at the clock to see what time it showed. I took the battery out the car last night to recharge at around 8:30PM so the clock should show that time. However it shows about 11:30. That the was around the time on Monday that I was working on the dome light when I got that spark. I'm starting to think this may be the problem.

[T77911S]

hopefully thats it!

[arbita1]

I didn't have time to check things out last night...the Giants were on. But I was able to confirm that the clock/dome light fuse was bad. I'm thinking this must be my problem. I will replace the fuse and confirm tonight.

I did notice also that someone (PO) stuck a 8A fuse in there when it calls for a 5A fuse. So now I'm hoping there was no circuitry damage as a result of this.

My fuel pressure tester was delivered yesterday and I don't even think I will need it. However I'm thinking that since I'm in the CIS mode right now (I've beed reading so much on it) I might as well check all the components out and correct any problems. I'd love to get the car running perfect.

I'll update later on...with hopefully good news.

[arbita1]

So believe it or not, the 5A fuse which provides power to the clock and the dome light will prevent the car from running.

I replaced the fuse last night and the car fire up and stayed running.

Thanks to this board otherwise my car would still be sitting idle.

I adjusted the CO setting with a voltmeter on the O2 sensor and set the idle to 950rpms. It's getting hung up in the upper RPM range, so I want to go through everything while I'm in there already and see if I can find any bad components. Also...I have a CIS fuel pressure tester now (That I didn't need!) so I might as well get some use out of it.

Thanks again to everybody.

If anyone has any ideas about the RPM getting hung up...please let me know. Decel valve? Thanks.