2 issues on 69, one with Quadrajet and the other a temp gauge...

[Kw69]

Hey guys, this has me stumped some. I have a new GM 350 crate engine dropped in on the truck that I bought recently. Has a new Quadrajet 4 barrel installed as well. Starts perfect in the am, but after running it around town and shutting it down for a few, it does not want to fire up. Just cranks and cranks and May fire but takes a few times. What's causing this? Has a new fuel pump, I mean everything is new...except the fuel line leading to the carb its original I think.. So I am slightly stumped cause I had to admit being only 42 and working on cars most of my life I have very little time working on Carbs... So what ur thoughts? Oh and on another note.... The previous owner also installed a new cluster with a tach. All is good except the temp gauge does not work.... I fixed a slight break in the wire but no avail. It does have a rapid fire coil and distributor from LMC. So two part question but both have me scratching my head... Thanks guys in advanced..

[geezer#99]

What's your initial timing?
Is your quadrajet a rebuilt?

[cdowns]

do you have a phenolic spacer under that carb to lessen the heat load and fuel perculating out of the carb

[hugger6933]

Look down the throat of the carb after shutdown is it dripping fuel or smoking? could be fuel leaking from the carb down the throat and filling into the intake making fuel puddles[basically flooding after shutdown]. Jim

[Kw69]

I believe the carb is new.. It does have a spacer below it that is metal, I will check the carb after shutting it down looking for leakage. The timing I was told is 0 TDC. Thanks so far! What's the thoughts also on the temp gauge? Thanks guys,
Kris

[Derek.Matirne]

I agree, it needs that phenolic spacer, I had that problem on more than one occasion... The carb is more than likely rebuilt, they haven't made a quadrajet in years, unless I just don't know about it... Newer quadrajet rebuilds should have those ports epoxied closed... I'm a believer that there's no better carb than a quadrajet, but only if you get a good one....
A quick check on the temp gauge is to ground it out, if your gauge moves, it's your sending unit, if it doesn't, then your gauge is bad,,,, hope this helps.....

[Kw69]

Awesome guys I will check on that spacer Monday when I get the chance. I don't recal having one of those on it. So that could be the couplet. Temp gauge is new so is the sender but will check those on Monday as well. Thanks Again for the advice guys.
Kris

[Phildeez]

What exactly is the temp gauge doing? I had issues with my gauge and the guys here helped me out. Does it stay on cold? Stay on hot? It basically works off resistance. The less resistance the sender has in the circuit the closer the needle will be to the hot. The same is true for the opposite. Say you have a splice somewhere in the sending wire that is creating unnecessary resistance the gauge will stay down in the cold zone like mine did. Poke around with an ohm meter and see what you find.

[TBONE1964]

What is it is or is it not doing on the temp gauge?

Does the needle move? Is it full hot?

I can help you with this part. Is the new gauge a original GM OE gauge or an aftermarket?

The carb if it is original q jet have plugs in the bottom of the float bowl area of the carb body that leak. After you shut down, pull the lid from the air cleaner housing and see if you see smoke coming from the carb. That is raw fuel leaking into the intake and will cause your hard start problem. The cab will need to be pulled and the base will need to come off and use JB weld on the plugs to stop the leak. I just had the same issue with my 70 K20 with a q jet carb and it is a very common problem.

[Kw69]

It stays on cold and does not move at all. Yep what u said makes sense to me now... Thanks for the advice, I will check it out!

[Kw69]

Cool I will also check this on the carb! You guys are great thanks for all the help. The gauge cluster came from LMC. It's an all new whole assembly cause now it contains the tach. I called the guy he said it worked fine with the original gauge set but when he changed over it would not work. He thought it was the wire cause the gauges are all new and the sender is new.

[Phildeez]

Here's a temp/ohm chart that helped me out. Let us know what you find.

[TBONE1964]

Originally Posted by Kw69

It stays on cold and does not move at all. Yep what u said makes sense to me now... Thanks for the advice, I will check it out!

Look under the dash where the temp gauge is. Is there a ceramic resistor there? It will be color coded with orange, blue or red.

If there is no resistor, you probably have an aftermarket temp gauge.

With the key in the run position (truck not started) pull the green wire from the temp sending unit and ground it very briefly. Have someone watch the temp gauge at the same time. If you have power to the temp gauge, the gauge should peg full hot when the green wire is grounded. Do not hold a ground on the green wire for very long as it may damage the gauge.

Even as it sets, you should see a very slight movement of the gauge when the key is turned from off to the run position. This will also tell you that the gauge has power. Of course if you want to check, you can put a 12V test light on the back of the gauge. It should be the terminal that is toward the drivers side of the dash.

Hope this helps, let me know.
Tom

[Phildeez]

If the gauge doesn't move at all it sounds like the wire is cut some where, not connected, or teflon was used on the sender...

[Phildeez]

On the carb issue, I would verify the timing. Too far advanced will make tough starts while hot.

[Kw69]

I checked late late night and it's an aftermarket gauge cluster. So I will do some testing this week on it again. It may have Teflon tape on the sensor and will check on Thursday. Thanks guys for all the help thus far, I appreciate it.
Kris

[Ronw435]

If you have one of the manifolds that has the heat dump underneath I would just get a couple I believe5/16 or 3/8 socket head plugs, tap the two holes that allow the exhaust to go underneath the carb in front and just plug it off. That should eliminate the heat problem.

[87Skier]

You can verify the gauge is not the culprit by disconnecting the wire and grounding it out.

Removed from the sending unit, it should be full cold.

Grounded, full hot.

[Kw69]

So far I believe the new sender is not the correct one. I am trying to find the original style one to work. I think the one that was installed only trips a dummy style light. I bought another like it still the same results. I plan on pulling the original form the original engine and installing it into the crate engine. I have been delayed some due to replacing the fuel lines and reclining the tank. The tank should be here next week. Funny thing is the replacement fuel line from the pump to the carb is different from the original. Doesn't have the same exact bends to it.... The company swears it's for a 67-70 V8 4 barrel carb... Me thinks it may work but stick out like a sore thumb.... I really like this truck and looking forward in driving it more. Even though I have an 09, there's just something about an old truck! Driving it, is just so right...

[Kw69]

I did check the gauge by grounding it out as u guys said, it's not the gauge! Thank God because that's a new cluster...thanks guys!

[Coley]

With respect to the hard/difficult starting after a shut down.
I would check the choke adjustment at the time of the problem. If the engine is still basically 'warm'....that choke plate should be nearly fully open.
I had this happen on a quadrajet once and I found that the choke system was not functioning correctly...whether its the choke pull off or the linkage.
If it doesn't start, quickly pop the air cleaner off....look down at the primaries and that choke should not be on/closed. If it is, you have to read up on the choke set up and get that dialed back in.
all Good
Coley

[Ronw435]

Sorry for the miss information. The socket head plugs were 1/4 NPT.