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Discussion Starter #1
Okay so I did an engine swap in a 1991 s10 blazer LT Tahoe edition. The guy I bought it from said it struggled to run. Before the swap it had the same condition, hard start and black soot from exhaust. I replaced the egr valve and tps and it ran better so I decided to proceed with the swap. After swap I got it running and had same condition. At idle if goosed it would just sputter and die and struggle to start again, found that there was a wire underneath the passenger side to set mechanical timing. I also did research and found I could have a bad iac so I replaced the iac and unplugged the wire to set mechanical timing and now it wont start at all. It's also 30°f here right now. Running to the end of ideas here. Any one know anything els that might help?
 

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Sounds like your TBI might be leaking fuel into the intake. Or did you swap that along with the engine?
 

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Discussion Starter #4
I tried to jump the connector and all it would give me was 12. I used the old intake and throttle body from the previous engine along with the sensors because most of the sensors have been replaced.
 

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Sounds like the TB leaking to me since that is the one primary part that wasn't changed that can cause soot and hard starting. How many miles on the Blazer? Have you pulled a plug to see if it's wet after trying to start it.
Another less likely possibility is a faulty computer. Not as common as a leaking regulator or injector, but possible.
 

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Discussion Starter #6
The engine has 0 miles and the body has like 126k. I just drained the oil and pulled the plugs. Oil smelt of fuel from flooding and the plugs are wet and look fouled so I'm going to try and put new plugs in.
336716
 

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You should have put new plugs in it. Those look like they've been around the block a few times.
 

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Discussion Starter #8
I installed new plugs and it fired up but doesnt quite start right. When first starting it fumbles until you give it a little gas then idles fine. But I notice lack of acceleration. Acts like it has no power.
 

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The plugs in the pic must be old plugs then?
 

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Either your pressure regulator or injector(s) are leaking if the plugs are getting wet and the oil smells of gas. The TBI unit is the only place gasoline can get into the engine.
Especially since the problem is the same with the old engine and the new one. Which you are going to ruin the rings on if you keep running it with gas washing the cylinder walls. The rings can't seat properly if there is no oil on the cylinder walls.
And eventually the bearings because diluted oil is a poor lubricant.
Years ago I would have said go to a JY and get another one, but finding one with the correct linkage arm might be hard today. eBay has rebuilt and used ones and injectors.
 

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Discussion Starter #11
I did an oil change and got rid of the bad oil. I drove it today about 5 miles not to far incase something happened. I found another throttle body at a jy but it might be gone now. I found it on a 4.3 In an astro van. Would it have the same injectors?
 

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Astros had the same 45PPH injectors. Linkage arm might be different, There are basically 2 styles. One is the old carb style and one is newer wrap around cable style.

Later style: Note the hole for the cross pin on the end of the cable.
336738


Early style

336741
 

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Just my 2 cents but the symptoms you describe sound like the distributor is off a tooth and has been rotated enough to get it to sorta run. May not be related to the original problem at all. It won't cost a thing to try except a few minutes of 'Time'. Pun intended
 

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Could be, but he said the original engine did it also. Suppose you could do it twice.
 

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Yeah but could be the original had low power for another reason and checking the timing is a quick & easy no cost item plus you never really know what the previous owner may have done. As many times as I have had my dist in/out I still miss the stab occasionally.
 

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Discussion Starter #16
I had it in a shop to get a new set of eyes on it and they told me my injectors are leaking. I'm going to bite the bullet and just pick up a new tb it's almost 29 years old and I've never done a tb rebuild so for sake of my mind I'm going new.
 

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Sorry, I'm just a bit touchy because this happens on here quite often. I tell someone what the problem probably is and they come back a couple days later so proud that they figured out what the problem was. Makes me question why I spend the time and effort trying to be helpful. Probably because a lot of them do say thank you.
Rant over.
 
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Hey, just had a thought. Maybe the injectors are leaking.?
Sorry, just could not resist. I did try but just could not.
 
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