Hard Starting Hot

[Rich72C10]

Well, the open hole Mr Gasket was too small, guess it is for a 2 Barrel QJet? I also the 4 hole one cause a odd low power / little pedal stutter when I was taking off. So I am back to normal.

Boo.

Next week I'll have the last of my bits to check the fuel pressure and I could put in a Mr. Gasket 1~5 pressure regular.

[Steeveedee]

The "Q" in Quadrajet means "four", so there's no such thing as a 2BBL Q-Jet. Maybe you got a spacer for a square bore instead of a spread bore. As far as the idle and off-idle performance, the extra height could cause a lean condition, or (more likely) you may have had a small vacuum leak at one or both of the spacer gaskets. I put a thermal isolator on an Edelbrock carb I had many years ago and it leaked like a big dog. I ended up sealing it with Form-A-Gasket. I was commuting long distance in those days and working a lot of overtime, so had little time to fiddle with it.

[geezer#99]

Didja know Steve that a dual-jet looks just like a quadrajet with blanked off secondaries.

https://cliffshighperformance.com/si...hp?topic=138.0

That’s what they were talking about.

[Rich72C10]

Okay, I feel stupid - that makes total sense Steevee!

Well, I am now looking at a AED Performance 1/2 Birchwood spacer for Quadra Jet. I emailed them a bit ago and John already emailed me back, he recommended the 1/2 over the 1 inch.

Though I have to find bolts that are 1/2 longer and my own open gaskets. Since they only sell the spacer and don't have the other bits for sale. I am sure I'll end up buying the wrong bolts a few times...because that is just my luck.

I didn't think to look for vacuum leaks with the riser on, though if I had kept the 4 hole on long enough I would have put my gauge on it. I did in fact put my gauge on after I put everything back together without the spacer (still getting 19~20).

Should I be putting on some sealer between the gasket and the spacer (top and bottom)? Or on every side?

[Carl Spangler]

Originally Posted by Rich72C10

Okay, I feel stupid - that makes total sense Steevee!

Well, I am now looking at a AED Performance 1/2 Birchwood spacer for Quadra Jet. I emailed them a bit ago and John already emailed me back, he recommended the 1/2 over the 1 inch.

Though I have to find bolts that are 1/2 longer and my own open gaskets. Since they only sell the spacer and don't have the other bits for sale. I am sure I'll end up buying the wrong bolts a few times...because that is just my luck.

I didn't think to look for vacuum leaks with the riser on, though if I had kept the 4 hole on long enough I would have put my gauge on it. I did in fact put my gauge on after I put everything back together without the spacer (still getting 19~20).

Should I be putting on some sealer between the gasket and the spacer (top and bottom)? Or on every side?

I would recommend a standard fiber gasket (with no additional sealer) on both surfaces.

I have to give you 'props' for continuing on this quest ................ after so many detours through the rabbit warren.

[Rich72C10]

I like to problem solve and I like (perhaps love?) working on the truck and learning things about it. Luckily the stuff I've bought hasn't cost a lot.

I've just realized I only need to buy one fiber gasket, I have one in "stock" from a rebuild kit I didn't use. Not sure why I ended up with a extra Qjet rebuild kit.

Edit Parts Order Update:

Ordered Fel-Pro 60255 (Amazon), the AED Performance 6155 Phenolic Birch wood 1/2 Spacers and ARP 200-2403 Carburetor Studs (Summit) for the back of the Carb. I am pretty sure I can reuse the Mr. Gasket's front studs as they were actually a bit two short IMO.

The fellow at AED (John Dickey) has been very helpful in email replies. Though while he says this problem that I am fighting definitely affect cars more since there is hardly any room for the heat to go to. For trucks, there is lots more room under the good for heat to dissipate and is surprised I am fighting such high temps post engine shut down on my carb bowl.

[geezer#99]

Why aren’t you making your own gaskets?
You can buy small sheets of gasket material. I have a piece here with Mr. Gasket printed on it. Bought at local speed shop.
A box cutter, some hole punches and bob’s your uncle!

[geezer#99]

Here’s likely the better way to keep your carb cool.

https://www.corvetteforum.com/forums...rb-cooler.html

[Rich72C10]

Thanks Geerzer - I’ll get that. You have totally read my mind thinking that is what I needed!!

As for making my own gaskets —- eh, no thank you LOL

[Rich72C10]

Looks like this is the one I would use.

https://www.rickscamaros.com/camaro-...xoCp9AQAvD_BwE

[Steeveedee]

That would be OK while it is running, but it will not eliminate heat soak once the engine is shut off.

[Rich72C10]

I have read some have combined the heat shield and a riser.... I'll be doing some experimenting for sure. F

For the record, I haven't yet ran into problems at all while running but I haven't driven when its 105 outside either. I hoping I can nip that in the bud before I even get to those outside temps.

[Rich72C10]

So I got my fuel gauge mounted - what a squirrely bouncy thing but I guess that is what happens with a mechanical pump?

Anyways, I used my iPhone to do a slow-mo video. I am getting peaks around 12~13 then lots of 8~10 peaks. Sometimes it gets to 5 pretty good, since the needle is not burrly.

So regulator a good idea??

[Steeveedee]

Stock pump and stock carb, millions were made this way. It's not like it's an Edelbrock. I wonder why we seldom saw flooding issues with the old AFBs that I grew up with?

The oscillations are to be expected from a pump with poppet valves.

[Rich72C10]

I am only checking the fuel rate as it was suggested it needed to be capped at 5psi, though I have read it isn't Qjet that is unhappy with >5psi.

[LNP]

Carburated engines fuel pressure should be like 5-7psi. Any higher and it will push past the needle and seat. Even after you shut it off it can still push past and cause the fuel to run over into the engine. Which would create a hard start like what you have described yours as. I would get a fuel regulator.

[Rich72C10]

Yep, I have one coming in tomorrow as I have read the same values. I also don't trust that Mr. Gasket fuel gauge, so I am getting Marshall 0~15 PSI that is oil filled.

I've read on another site that my fluctuation is not right either - the big swing up to about 13 PSI. Though I know I haven't a blockage in my return line from the pump. But I am not find much what to expect on Fuel Gauge readouts with mechanical pump - I'd image some kind of fluctuation.

[Rich72C10]

I finally took the time to replace under the cab/bed rubber fuel lines. I have three: main fuel, return, and vent. When I took off the rubber main fuel line, well it came apart in like 3~4 bits - it disintegrated as soon as I pulled on it. The other two were in much better shape but that is not really saying much. I also replaced the main rubber fuel line on the top of the tank. While the main rubber line wasn't disintegrating, I could tell it was collapsing in the middle.

I even ended up replacing the main rubber fuel line to the fuel pump, as the writing said "Not for Fuel ...." so I freaked the F'out! But once I got the new main rubber fuel line installed and looked at the one I had put on a month or so back, the rest of the message would have been "... for injector"! Might as well be overly cautious when it comes to your gas lines.

Will any of this help my starting issues, don't know / don't care. It needed to be done and was WAY overdue by like 10+ years. If my truck catches on fire because a busted rubber fuel line, who cares if I had a hard time starting ;-)

[CC69Rat]

You need a fuel pressure regulator instead of the gauge. A stock ACDelco pump will be around 12psi, and what I'm thinking may be happening to you is very similar to the Edelbrock 1406/1407 carbs. They cannot handle anything over about 5psi. In fact Edelbeock even suggests using their fuel pump instead of a stock pump. I'm sorry if I didnt specify in my comments, but as others have mentioned the needle and seat issues / scenario could be the issue .. but the fuel lines you mentioned above will likely help the situation too.

But yeah man, a Mr Gasket fuel pressure regulator will allow you to back off the pressure from the stock 12-13 to whatever it takes to make your carb happy. 5psi would be my bet. I'm watching the post, hang in there man. Well get it figured out.

[Rich72C10]

The Fuel Pressure gauge came first, matter of fact my 2nd one that is oil filled came in today while still waiting for the regulator! Getting the gauge is just to see what is actually going on and the line replacements was done because I knew they were very questionable before I even thought about regulating the pressure

So no worries, all the information provided has been great and very useful to me. All great leaning IMO!

[Rich72C10]

Okay, have my Solimeta Oil Filled fuel pressure gauge installed - man its like night and day different from that Mr. Gasket gauge. I don't think I am even getting a 1/4 PSI fluctuation!

Here are three photos for reference, this is a Delphi MF0002 3-port pump. Rechecking, its data sheet lists it as a 9 PSI pump.

Photo 1: Idle

Photo 2: Climbing slowly up to near WOT

Photo 3: Near WOT

Shut her down, then started up again, let the Truck idle for a bit and got her good an warmed up. The pump then settled about 6.7~7.5 PSI. Then as I gunned her, she dropped to right about 6 PSI.

[BigBird05]

Just to double check. The new fuel line that you installed is for ethanol type fuel, right?

[Rich72C10]

Well, I sure hope so - that is what I told O'Rileys what I wanted / needed. I even said, need fuel line for "normal" car ethanol fuel. He took me back, had me help match up the sizes and hold it to cut the length I wanted.

Gee, now you got me all worried that some fool box store is selling fuel lines that are not meant for gas that everyone gets!


Made me look up the part number on their website:

Gates Safety Stripe II Fuel Line/PCV/EEC Hose
Multi-purpose hose for use on return fuel lines, PCV and EEC systems, and for fuel return hose connections on diesel fuel injection systems. Approved for use with leaded and unleaded gasoline, diesel and gasoline blends of ethanol (E85), methanol and ethers (up to the legal limits allowed by the EPA).
Working Pressure (psi): 50 psi

[Steeveedee]

You just never know. One of my sons had a '70 Dart, and when we went to get heater hoses, the parts guy started cutting 1/2" fuel hose. It said so right on the box. What in the heck vehicle has 1/2" hoses for fuel?

[Rich72C10]

Not a Dart! LOL

I hear back from Quadrajet Power all on my stats on PSI levels and photos of my gauges (both cold and warmed up) they said I am fine with my levels... so I guess I'll keep my regulator on the self, for just in case.