new motor

I recently had a guy install a newer model 2.8 motor in my '84 s10 4x4 to replace the old worn out 2.8 that was in it. Now that I have it back it is missing pretty badly and if you pull off the back two spark plug wires there is no change in the idle. Any other ones and it makes it run worse. Before you say take it back this is the 3rd time I would have to do that. I am fed up with the guy and want to try and fix it on my own. I think this motor is from a fuel injected motor because there was no place for a fuel pump. The guy installed an electric fuel pump instead. I don't have much faith in this guy. What do you think could be wrong? Any help would be greatly appreciated.

Scott

I recently had a guy install a newer model 2.8 motor in my '84 s10 4x4 to replace the old worn out 2.8 that was in it. Now that I have it back it is missing pretty badly and if you pull off the back two spark plug wires there is no change in the idle. Any other ones and it makes it run worse. Before you say take it back this is the 3rd time I would have to do that. I am fed up with the guy and want to try and fix it on my own. I think this motor is from a fuel injected motor because there was no place for a fuel pump. The guy installed an electric fuel pump instead. I don't have much faith in this guy. What do you think could be wrong? Any help would be greatly appreciated.

Scott

The 2.8 was used with or without injection (port or TBI). I am guessing here but is your engine carb?

Also, did the mechanic change the intake? If so, he may have screwed up the intake gasket. Some diagnostics are called for here.

You might be better off having a second opinion from a different mechanic.

The 2.8 was used with or without injection (port or TBI). I am guessing here but is your engine carb?

Also, did the mechanic change the intake? If so, he may have screwed up the intake gasket. Some diagnostics are called for here.

You might be better off having a second opinion from a different mechanic.

Yes it is a carb. It is the same old intake. What kind of diagnostics are you thinking?

Yes it is a carb. It is the same old intake. What kind of diagnostics are you thinking?

Make sure you have spark to the plugs first. Then take some carb cleaner or oil and spray the back of the manifold for those cylinders and see if the engine smooths out.

Make sure you have spark to the plugs first. Then take some carb cleaner or oil and spray the back of the manifold for those cylinders and see if the engine smooths out.
Ok, I know there is spark to the plugs. Found that out when I was pulling off the wires to check. I'll try the carb cleaner thing. What will the carb cleaner do?

With something like this it is always spark or fuel. Check spark first, like Mikado14 sayed, then go for fuel. Let us know about the spark and we will go from there.

That sounds like a serious crock of shit for you, I sure woudn't take anything back to that mechanic.

The first question that I would ask is where the motor came from, and did you buy it (or the mechanic) Did they compression test it first?

And the biggest question is will whomever sold you the motor back it up.

I really hope not, but To me it sounds like very low compression in those 2 cylinders.

Get a compression test done first, even if they claim it was good, and then decide from there.

If the motor is junk, and they back it up try getting a 3.4L (a direct bolt in from what I can tell), and you'll be much happier... but look into it first on this web page first
http://s-series.org/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=21&page=1

Good Luck

How about taking it back to the guy that installed it and having him fix his screwup.

You didn't pay him for a bad running motor.

Did you get any kind of warranty on the engine?

Regardless, this truck has new engine and the installer should not allow an engine or truck to leave the garage running like shit.

he didn't actually say new motor, except on the title, he sayes newer motor.

I might be wrong, but I'm thinking newer used motor. That's why I'm thinking low compression

But still, again, the installer should not let it leave running like junk.

I can't agree with you more BlazerLt, I would really hope that it was the installer that bought the motor, and that he will back everything.

I know that If I had a customer that brought me a bad motor and has me install it I sure wouldn't cover it.

Although I wouldn't install any used motor without doing a leakdown test first. I'd back any compression problems then, but sure not bad bearings or something that I can't reasonably be expected to detect

Ok...here's an update. I could not find my compression tester so I just went with the easiest suggestion and cranked it and sprayed carb cleaner at the back of the manifold. The idle actually picked up when I sprayed it. That got me to thinking. If this is a newer model motor then the intake for the newer model probably isn't exactly the same as this carb intake that is on it now. The gaskets for the motor were for the newer model motor so they are probably the wrong gaskets. This is supposedly a new motor. I bought it from a guy that bought it from city motor company and never used it. It was still in the plastic and not rusted or anything. So does my theory hold water? Or would the gaskets be the same for either motor? My next plan is to take off the intake and see what i've got. Oh and I won't take it back to the guy cause frankly he doesn't have a clue. I've already had to wait 2 months to get the truck back from him. Then I went to pick it up and it was shaking horribly. I guess the newer model motor wasn't balanced the same as the old cause he said he had to get a different flywheel and clutch to fix it. I know some V-8's are balanced at the flywheel so I am assuming this newer model motor is to.

Well they changed the 2.8L a little in 85 switching the main journal size to a bigger diameter, and changing the rear seal to a 1 piece unit. SO I would assume that you have the newer motor.

some heads aren't compatable with others so you might have found the problem

read this link on the 2.8L heads, and see if it helps you out
http://users.spec.net/home/emxjc/heads.html#Over

Turned out the intake gasket on the passenger side in the back was pushed down from the guy that installed the intake. Put new gaskets on and put everything back together. It runs great now (for a 2.8). Had to replace a fuel line that the guy left leaking too. Will not be visiting him anymore. Thanks for all the help.
Scott

Turned out the intake gasket on the passenger side in the back was pushed down from the guy that installed the intake. Put new gaskets on and put everything back together. It runs great now (for a 2.8). Had to replace a fuel line that the guy left leaking too. Will not be visiting him anymore. Thanks for all the help.
Scott

Hope ya didn't pay the guy, if you did, beat him till he gives you the money back...
Glad ya got it working though..:)