No fuel to CIS

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doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

No fuel to CIS

Post by doopsx3 » Sun Apr 10, 2016 11:32 pm

I have a 87 Cab that has been sitting many years and I was told "ran when parked"...after cleaning the fuel tank and replacing the in tank pump I bench tested the main fuel pump and it proved good. My problem is the fuel pumps will only operate after the engine has been cranked over and then only for a short time. I know that the fuel pump relay senses the rpm signal to tell the pumps to continue to operate but aren't the pumps suppose to turn on when the ignition is initially turned to the on position and during cranking? Why would my Cab be doing this...

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Briano1234
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Re: No fuel to CIS

Post by Briano1234 » Mon Apr 11, 2016 8:42 am

Upon first key in to the run the fuel pumps should cycle for 4 seconds to prime the system.
They are feed the run signal off the Coil. Which in turns runs the fuel pump relay.
every time a cylinder if firing the fuel pump will cycle.

If you are not getting the 4 second prime at key in to the run position
Suspects are the Ignition switch.
Fuel pump relay.

The Starter side of the ignition switch also powers the Fuel pump relay.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:

doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

Re: No fuel to CIS

Post by doopsx3 » Mon Apr 11, 2016 9:04 am

Thank you I will try the horn relay swap for the fuel pump relay temporarily to see if that fixes the issue...if not I will check the ignition switch...

doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

Re: No fuel to CIS

Post by doopsx3 » Thu Apr 28, 2016 10:19 am

the relay horn relay swap worked and what actually happened was the main fuel pump failed....replaced with a new Bosch unit and now I have fuel to CIS but unfortunately I have cold start issues

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Briano1234
Whats that smell?
Posts: 3987
Joined: Mon Mar 21, 2005 5:45 am
What year is your cabby?: 1992
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Re: No fuel to CIS

Post by Briano1234 » Thu Apr 28, 2016 11:28 am

Look at the Warm up regulator, and or the cold start injector.
Timing could be off, and of course the o2 sensor...
You could try unplugging the o2 sensor to see if it is the issue, as unplugged it will force the engine in to closed loop.
If your Duty cycle is off that too, then there is the ubiquitous vacuum leaks.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:

doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

Re: No fuel to CIS

Post by doopsx3 » Thu Apr 28, 2016 12:02 pm

only a billion things ...lol....new Bosch O2 sensor is installed.....cold start injector is getting required signal...timing is spot on

doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

Re: No fuel to CIS

Post by doopsx3 » Thu Apr 28, 2016 12:04 pm

I just touched the 3mm allen screw adjustment for CO and the dang thing started and ran fine....letting engine cool down bit to see if it will start again

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Briano1234
Whats that smell?
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Re: No fuel to CIS

Post by Briano1234 » Thu Apr 28, 2016 2:05 pm

Probably what it was......
I can't remember if that screw has a o-ring.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:

doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

Re: No fuel to CIS

Post by doopsx3 » Thu Apr 28, 2016 11:15 pm

not the air adjustment screw on the back of the plenum ...but the one next to the fuel distributor...the one you adjust when your setting the CO levels.....unfortunately now I can't get it to idle down unless I adjust that screw to where it won't start back easily....idles around 12-1400 rpm

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Briano1234
Whats that smell?
Posts: 3987
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Re: No fuel to CIS

Post by Briano1234 » Fri Apr 29, 2016 6:29 am

That may be a timing issue, as the co2 was mis-set to accommodate for duty cycle adjustments or timing that was off.
I would first do the static timing to validate that all the marks are set, then adjust the duty cycle.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:

doopsx3
Posts: 8
Joined: Thu Jan 14, 2016 8:47 pm
What year is your cabby?: 1987
Do you own a Cabriolet?: Yes

Re: No fuel to CIS

Post by doopsx3 » Fri Apr 29, 2016 9:26 am

Timing should be spot on....I replaced the timing belt and did an ignition timing check afterwards but will check again....what do you use to check duty cycle....and how....dwell meter???....thanks for your help

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Briano1234
Whats that smell?
Posts: 3987
Joined: Mon Mar 21, 2005 5:45 am
What year is your cabby?: 1992
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Location: Duluth, Ga
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Re: No fuel to CIS

Post by Briano1234 » Fri Apr 29, 2016 5:59 pm

Kammy has a how to at www.cabby-info.com

Duty cycle is a reverse of Dwell, but Kammy lists both I believe.
Also Harbor Freight sells a DVOM with Dutycycle and dwell.
Briano

Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click.... :screwy:

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