Why is my 1985 s 10 2.8 engine so hard to start ?

The intake is fine.

I dont have that piece in my carb. My car is a rochester varijet 10785350

d to start. I have done everything i know to fix this but no luck yet . I h ave put a re-manufactured carburetor on it.I have checked all the vacuum li nes,replaced the fuel pump. manual pump. I have a clear fuel filter that lo ok good. I have done a tune up,plugs,wires,cap,pickup module,exc... I have even done a compression test that passes easily. The engine runs good, its just hard to start. Im stumped !

hard to start after its been running.

ng on the side of the carb and adjust it.

I converted the choke to manual.

Well then, did you check to see if there is any fuel in the float bowl in the morning? That's really about all it can be. Or that combined with a fuel line that is also empty, and possibly a fuel pump issue. Did you at least look to see if the accelerator pump is squirting in the morning?

Visually check to make sure your choke is working correctly.

ard to start. I have done everything i know to fix this but no luck yet . I have put a re-manufactured carburetor on it.I have checked all the vacuum lines,replaced the fuel pump. manual pump. I have a clear fuel filter that look good. I have done a tune up,plugs,wires,cap,pickup module,exc... I hav e even done a compression test that passes easily. The engine runs good, it s just hard to start. Im stumped !

le hard to start after its been running.

it runs fine. no black smoke or rough running.

Not yet but im going to soon. Ill let you know.

Coking is less likely on a carbureted or port fueled engine. Fuel wash prevents that occurring. That's an issue with diesels and GDI engines.

Yes but it has a lot to do with how the fuel enters the engine. In a diesel, the fuel is injected directly into the combustion chamber. Same as with Gasoline Direct Injection. That means that any fuel, or oil, that gets into the intake system on these engines can *burn* onto the

*back of the inlet valve* and turn into a hard carbon build up - coking. If you're wondering how fuel gets into the manifold if it's injected directly into the combustion chamber, think of PCV and EGR systems. Also, some GDI systems use valve timing as a pseudo EGR system.

This should explain it;

and this;

Different kind of coking. That's combustion chamber coking.

I am surprised you bought a *rebuilt carb*. Those are not generally considered worth rebuilding nor were they designed to be rebuilt. What is generally done is a brand new replacement and, from what I recall from that era, they were not expensive as a new part. Certainly the parts and labour cost would exceed the cost of a new car, if my memory serves me correctly.

This may be where your issue lies. The Varajet was supposed to be a lean burn unit for pollution control. It may be set a tad too lean. That will definitely give you hot start issues at the very least.

Errata

parts and labour cost would exceed the cost of a new carburetor.

It's not all that common, but there are certain vehicles that are prone to it. GM's G vans from the 80's or 90's were one, and I had an Allante with a severe case of it. I believe I also had a 2.8 Chevy engine in some vehicle with the problem. I think it's more likely with very high underhood temps.

I was leaning very strongly toward this being the case, that the choke is not leaning down enough. But I suggested earlier than he try manually blocking the intake to simulate aggressive choking and he said that didn't help.

--scott

It's a cold start problem with a carburetor. This should be dead simple to fix. He needs have an old fart mechanic look at his carb.

You'd think so. But back in the seventies _everybody_ had a carb and _everybody_ had cold start problems. It was just considered normal. Hmm, maybe there is a correlation here.

--scott

I'll take your word for it. I live in the tropics so cold starting is not t oo much of a problem. I use to have a Barracuda that the previous owner dis connected the choke linkage. As I recall, the bimetal spring was located in the intake manifold. I'd have to idle the car for a while until the car wa rmed up. Beats the heck out of me why people want to disconnect an automati c choke.

Yes, which is why I'm inclined to think that there might be a bit of trolling going on. None of his replies seemed to ring true. In fact, his replies seemed to be, "it's not that" mostly.

You could be right about this.

Not everybody. I had no problems starting - winter or summer.

I can say the only time I ever had a cold start issue in my old 85 SBlazer with the 2.8 it was due to the baseplate heater not working.

That carb is VERY fussy when it comes to the choke adjustment and they were always set on the lean side. Do you have the list of settings for all the linkages and controls?

Is this a feedback or non-feedback carb? They used both depending on the emissions controls you had.

What is your current starting procedure for cold and warm? You mentioned you converted to manual choke? Why? Was that done before or after the hard starting?

What fuel are you running? Does it have ethanol in it? If yes, that alone will cause starting issues in a carb not adjusted for it.