Author Topic: Fuel Pump? Truck died... Can't diagnose.  (Read 32088 times)

Offline Spool

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #105 on: February 20, 2018, 12:27:16 PM »
Thanks BD.

Does the valve cover pose a threat to the plug cables due to heat as well, or just friction?

When shopping for wire looms, I can't help but notice they all have the plug cables running parallel; is there a certain distance between any two cables the prohibits spark crossovers?

I'd also been looking at other chrome wire looms as the passenger side of the engine doesn't have one.
However, I see the one I have now is mounted near my valve cover. In removing this bolt, will I also be loosening the valve cover itself?
I wouldn't want to break or compromise the seal I have now on my valve covers.

For wire looms with a with a protective sleeve, maybe something similar to this:
https://www.amazon.com/Proform-141-636-Ignition-Wire-Loom/dp/B0006V2BKA/ref=pd_day0_263_8?_encoding=UTF8&pd_rd_i=B0006V2BKA&pd_rd_r=N7RN2G47R53TBGZ67BEB&pd_rd_w=lhVdX&pd_rd_wg=6zVfp&psc=1&refRID=N7RN2G47R53TBGZ67BEB

And just for sharing purposes/ and a future purchase... How sharp looking is this configuration?
https://www.summitracing.com/parts/rnm-1101-90-k?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-r-m-specialties&gclid=Cj0KCQiAq6_UBRCEARIsAHyrgUzK6VnulcFtbDrBKcLdslAz9tFjmE_7d4yQWr78sLaDRDERqqMl-5caAvhREALw_wcB

Offline bd

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #106 on: February 20, 2018, 03:40:29 PM »
Spark plug wires easily tolerate engine heat.  The exception is exhaust heat, which will break down insulation.

I use R & M Aluminum Wire Looms on my 5.7L in an over/under configuration.  Drivers side wires are loomed as pictured; passenger side wires route to the spark plugs from below the exhaust.

Whatever style loom you decide to use, make sure the looms are compatible with the diameter of spark plug wires you have.

In itself, removing a valve cover bolt to install a new loom won't invite a leak.  But as an added precaution and to set your mind at ease, smear a dab of silicone under the bolt head before reinserting it into the hole.  Make sure the added thickness of the loom under the bolt head allows adequate thread engagement.  Be careful to avoid overtightening the bolt when reinstalling so as not to distort the cover. 
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Spool

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #107 on: February 21, 2018, 12:14:47 AM »
That's great. You are running the wire looms I was window shopping on. They look super sharp, did you have to order extra long cables for that?
I'm assuming the spacing between the plug cables are far enough to avoid spark crossover?

Mine 8mm, so I'll keep that in mind when shopping.

Also, good to know I remove the valve cover bolt without causing a leak.
Do those bolts actually hold the valve cover down in addition to the silicone between the block and valve cover?
I'm assuming, something as gentle as 22lb/torque as with the spark plugs would be fine in tightening the valve cover bolts again?

Offline bd

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #108 on: February 21, 2018, 09:41:19 AM »
Run 4 & 8 and 5 & 7 along the outer guides of the looms to keep the wire pairs separated as far as possible.  Longer cables may be required to use the R & M looms - measure for proper fit.  Valve cover bolts are only 1/4" in diameter.  Don't use a torque wrench; tighten by hand to less than 5 lb-ft (<60 lb-in).  Think of the valve cover bolts as more along the lines of screws.  Overtightening will distort the valve covers and create oil leaks where none existed.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Henry

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #109 on: February 21, 2018, 11:41:59 AM »
Hi Spool:
Way to go...this is a big job no matter what your experience level of shade tree mechanical work...I am relieved that the oil pump drive connection cooperated so easily.

Yeah, BD is right, the main spark crossover wires are 5-7 and 8-4 since they run a long distance together and fire consecutively. The other spark crossover wires are the 3-6 and 2-1 combos that also fire consecutively....since these cylinders are not next to each other and in fact are in different banks, the only place the wires are close to each other are at the distributor...so they should not run parallel for any significant distance...if they just pass each other or touch in one place that is OK.

What information was provided with the distributor concerning the vacuum advance setting of the distributor? I am just curious and this should not be a point of concern...the vacuum advance is more for fuel economy where the mechanical centrifugal advance in the distributor rotor is for performance. FYI, my Chevy service manual has a typical early 1970s HEI distributor vacuum advance settings of 0 degrees at 4" of Hg and 18 degrees at 18" of Hg for your engine which would be a 350 4BBL V8 with light duty Federal emissions.

Well, your truck should not have any more stalling problems for a long time and if they do start again you should be suspicious of leaking vacuum lines and the fuel system as the culprits as you have all new ignition parts now.

Regards,
Henry

Offline VileZambonie

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #110 on: February 21, 2018, 06:13:15 PM »
Well, thanks to everyone, I was able to successfully start my truck.
Took it out for a test drive today and everything was smooth. The idling is quieter than was before.

After replacing the distributor and rewiring my plug cables, I had someone rotate the distributor for me as I used the timing light.
When we started it was at 8Degrees AFTER TDC, but it currently sits at 8Degrees BEFORE TDC which was done by turning the distributor ever so slightly counter-clockwise.

I've attached a picture of my Distributor bolt and clamp in place showing the connection on the flange.

As for rewiring my spark plug cables, I took the opportunity to install my spark plug heat sleeves.
They are conveniently 8inchs long which gets me past my headers.
However, 3 of the cables on the drivers side are resting on my valve cover; is this bad?
I was unaware of having spark crossover on parallel plug cables; I'll mix it up a bit.

I want to thank you again for all your help. I was able to learn a lot, fix my truck and enjoy the process thoroughly.
It's a lot of fun, and a lot more fun when it works.

Thank you again.

Just poked my nose in this thread and have not read the 8 pages but did notice your distributor clamp is on upside down. Is there a reason or is it a goof?
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Offline Spool

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #111 on: February 23, 2018, 01:17:53 AM »
Just poked my nose in this thread and have not read the 8 pages but did notice your distributor clamp is on upside down. Is there a reason or is it a goof?

You know something... This may explain the situation I had this evening.
After about 4 miles, the engine was idling harshly while in drive at red lights and stop signs.
And upon acceleration, the engine would burp, if you will, almost like if you were running out of gas. Like a stutter before actually accelerating.

When I got home, I looked at the distributor cap markings and they appeared to still be aligned correctly from a distance.
However, my timing light showed it was no longer at 8degrees BTDCC... But way before 14degrees BTDCC, almost at due north.
The groove on the flywheel is timing at say 12'oclock, where my timing tab is at 2'oclock.

All this left me thinking, the distributor slipped as I didn't tighten the bolt enough.
The orientation of the bolt clamp is in the same orientation as when I removed it.
(I've attached the reference photo I took when removing it originally that shows the little bump on the end pointing upwards.)

So, it sounds like I need to time the engine again.
And before doing so, reverse the clamp.

While on the topic, where do you guys set your TDCC and why?
I set it to 8degrees, but the truck feels different than it used to; I never knew what the engine was timing at before I did the job.
Any pros or cons?

Also, Henry, no specs or literature came with the new distributor.
It's a Demotor HEI Distributor 65k Volt, and I didn't see anything online that was specific to this model with regards to vacuum pressure.

Thanks guys.

***EDIT***
I stand corrected... I just noticed my mistake.
On February 13th I posted an image of the clamp caked in grease, dirt and oil when asking the best way to clean it, and it is in fact not in the position of my reference photo.
I must have turned it around while cleaning it... Foolish mistake that I won't make again.
(I've reattached the original image to show my error.)
« Last Edit: February 23, 2018, 01:45:31 AM by Spool »

Offline Irish_Alley

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #112 on: February 23, 2018, 07:38:35 AM »
i set my base at (been years since i timed it so going off memory) around 12° with the vacuum advance unhooked. and on manifold vacuum instead of ported. than way when the engine is warm it can start up easy and once it gets started im around 26-30° or something like that
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Offline Henry

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #113 on: February 23, 2018, 11:26:30 AM »
Hi Spool:
Yeah it sounds like your distributor came loose because your clamp was upside down as Vile noted...it will still hold upside down, but it is point contact which is not as solid as surface contact when the clamp is oriented properly and should never come loose when tightened.

I set my engine timing at the specifications set by Chevy...the reason is because the timing of a oem engine is determined by engineers to be optimum for performance, economy, driveability, and reliability. If you have a modified engine (cam, compression, fuel system) you may need to change your timing if the reason you have modified your engine does not suit your needs (hot rodding, racing, making noise...who knows). If you want to modify your engine for fuel economy, the factory timing setting is optimum.

Your engine sounds like it is stock or oem...basically. I see from the photos you have an aftermarket carb, but it is probably 750 cfm air delivery which is the same as the original carb on your engine which was possibly a 750 cfm 4-barrel (Rochester 4MV) or a 425 cfm 2-barrel (Rochester 2GV). Your ignition system was originally the points type of ignition with a separate coil. Now you have the HEI ignition which is a oem style ignition for a later model year (1976 onward) than your older ignition. It is more reliable and requires less maintenance. It replaced the points type  ignition to provide a longer and hotter spark for emissions....but this turns out to be good for performance as well.

For your original oem set-up, it is hard to determine what the oem specs were...there were many considering the engine/trans combination and configurations, and whether or not it was a California truck...timing could have varied from 8 to 12 degrees BTDC. Spark plug gap was .035 inch.

For your new oem set-up, I believe the your engine is close to what was a 350 cu in, 4-barrel carb, light duty, auto trans. The spark plug gap is now .045 inch and the timing is   8 degrees for Federal emissions class...it is 6 degrees for California emissions class. Even though you live in CA which has tough standards, I dont think anyone cares or checks what your old truck's timing is...so you can set your timing anywhere between 8-10 degrees for best compromise in performance, fuel economy, and driveability.

*I was only asking about your new distributor's vacuum advance setting because I thought that you mentioned the ad for the distributor said it had a adjustable vac adv setting. I am ignorant about adjusting the vacuum advance...never done it and have never seen any documents showing how to do it for a Chevy HEI distributor. There were no less than 5 different HEI distributors available in 1976 and I think the differences were all in the amounts of centrifugal and vacuum advance...truth be told all would work fine on any Chevy V-8 engine.

Regards,
Henry   

Offline Irish_Alley

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #114 on: February 23, 2018, 01:33:22 PM »
Hi Spool:
I set my engine timing at the specifications set by Chevy...the reason is because the timing of a oem engine is determined by engineers to be optimum for performance, economy, driveability, and reliability. If you have a modified engine (cam, compression, fuel system) you may need to change your timing if the reason you have modified your engine does not suit your needs (hot rodding, racing, making noise...who knows). If you want to modify your engine for fuel economy, the factory timing setting is optimum.



this isnt always the case, most times the engines were tuned for emission reasons. this is why the vacuum advance is on ported vacuum instead of manifold. so it only advances your timing when the throttle is open and you may performance issues (not major). most times for every degree of timing you can advance youll get a small HP gain.

take a read here by rich weyand
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When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Spool

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #115 on: February 23, 2018, 02:59:22 PM »
Alright...
I flipped the clamp, realigned the markings to align at Cylinder 1 and began timing.

I rotated counter-clockwise to align the timing at 8degrees, the only problem is that the engine is not performing well.

It's very rough on an idle and shakes the truck.
The engine sounds like it's struggling to perform.

Any ideas?

Offline VileZambonie

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #116 on: February 23, 2018, 03:41:03 PM »
Double check you have the firing order correct and then try advancing the timing. did you validate TDC at zero is truly TDC?
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Offline Spool

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #117 on: February 23, 2018, 03:48:46 PM »
Hey Vile,

I found TDCC by going under the truck and turning the flywheel by hand until lining up my rotor with the marking on the distributor that indicated Cylinder 1.
https://www.youtube.com/watch?v=7ORVanWWuro&feature=youtu.be

I'll double check the firing order now.
I'll try advancing to 8degrees ATDCC and see if that does the trick.

Is there any harm or foul in turning the distributor too much in either direction?

Offline VileZambonie

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #118 on: February 23, 2018, 04:01:00 PM »
The pointer and the indicator need to be at zero when the piston is truly at TDC if you are going to use it to baseline your timing with a timing light. If you haven't done that, in the interim, advance it incrementally until it pings and then back it off. This will help you get it running good for now.
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Offline Spool

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Re: Fuel Pump? Truck died... Can't diagnose.
« Reply #119 on: February 23, 2018, 04:23:46 PM »
When I adjusted my rotor to point at Cylinder 1 by rotating my flywheel, it put my groove mark just at about 16degrees BTDC.

I'm going out there now. What do you mean when you say, 'until it pings'?

I'll also be removing the Vac hose and plugging it while I do my timing; something I did the first time but not earlier today.
« Last Edit: February 23, 2018, 05:47:49 PM by Spool »