Ok I just purchased a few more complete k5 blazers for parts for a few of my chevy pickups and I want to sell the engines. But before I do tat I want to get them running. One k5 has a 305 tbi in it. Here is what I have, I have spark I have plenty of cranking I've obviously got compression. I couldnt crack the fuel line to see if i was getting fuel which I am pretty sure i'm not getting. But I poured a small amount of gas down the intake and yet it still wouldnt start. I waited for awhile soit would all dry up cranked it a bit and had my buddy shoot some ether in there adn that didnt get it rollin either, I am running out of ideas. I figured the spark adn fuel alone would get it to fire off but it didnt. I can crack the line at the throttle body because its seized together and I dont want to risk breaking the line. I am more into the carburetted enines and not too familiar with these so i figured I'd ask for some help here. Any ideas?

The other blzer i bought is also a 305 but its carburetted and I am having similar problems. Athough i have fuel to the carb I have spark I think the start is toasted it doesnt crank right. it will give a good 3/4 crank then like hit a high compression spot and drop way down then repeat that again then the starter starts smoking so I have to look into that one a bit more.

 

Have you tried messing with the distributor position? Being TBI, it likely has a computer controlled distributor.

On the carb'd 305, this sounds exactly like timing is off.

 

On the TBI first make sure the distributor is pointing to the correct position. Check the fuel pump by turn the key to the "on" position with out cranking the engine. If you can here it buzzing, you're ok. If no buzz you better hope it's the fuel pump relay.

The MAP sensor is very important, if it's dying or dead it will never start. First make sure the vacuum hose isn't clogged up. Then have a friend crank the engine and check to see if the injectors are spraying out gas. If not then most likely the map sensor went dead. It's three wired with a vacuum hose. I always have an extra one on me just in case.

Lastly, the dizzy module might be dead. I also carry a spare with me.

Car'b, your on your own on that, I'm all about fuel injection.

One last thing, I've never heard of a 305 blazer? But I might wrong. I kind of wish mine was a 305. Less gas.

 

Swart you might just be right because the guy I piced both these blazers up from said that the one with the carb the original owner just did the plugs wires cap rotor and everything and its all in a garbage bag in the back seat. So he might have twisted the the distributor while changing everything... I just figured it was the started because it doesnt seem to grab everytime and it smokes and sputters a lot. smokes bad. so i was going to wait until the TBI was running and steal the starter out of that for a donor to get the other running.

right on the radiator support says 5.0 litre. een theother blazers I have had and parted out said 5.0 litre right on the radiator support. The first one I had i was kind of surprised but whatever.

The fuel pump was the first thing I checked, it works I have good spark as well. I know it doesnt spray fuel because when I first got it home threw a battery on it I never smelled gas or saw wetness or anything. I will be borrowing my dads noid lght or whatever he called it to check the injectors tomorrow hopefully.

I will post what happens tomorrow when i get things rolling hopefully. Thanks for all te help so far guys.

 

Well i met success and met failure. I couldnt get the tbi to start at all. the battery i have been using to try and get it started isnt doing well either so I put that one on hold and went right to the carburetted k5. I grabbed the distributor and gatve it a light twist not expecting it to move and it moved a lot turns out i am missing the keeper thatholds it in. i twisted it for awhile and i got it at one point to backfire a few times. I twisted it so far the the vacuum advance, the little nippleend is pointing at about 11 oclock and I jammed a screwdriver onto the side of it and it fired right up. sounde like **** but it ran. so I am assuming it is off at least 1 tooth maybe a 2. I need to scrounge up a keeper and play with that tomorrow. made my day that it started though. I will try and get a pic of what it looks like just to get it running and see if i can post it up here for you all to see.

 

Sounds good on the carb'd K5... Not so good on the TBI.

Typically, the vacuum advance is pointing straight towards the front of the truck, no where near the firewall (if that is the position you now have it in). If that is the case, then you have it more than 2 teeth off... There are only 12 teeth (I think..) on the bottom of the distributor so you have it about 4-5 teeth off. Hopefully the timing chain has not jumped. A compression check should tell you if it has.

As far as the problem with the TBI K5 not starting... Have you used the noid light to see if the injector is getting the proper signal from the ECU?

You might want to get an adapter for the main fuel line so you can put a fuel pressure test port in. Then you could test the fuel pressure.

 

no i havent used the noid light on it yet my dad couldnt find it. he has to look in a few more spots hopefully the next day or two and I will get that all tested.

Anyone know any video hosting sites that I can post a video up so you all can see it? Me and my buddy took a video of it when i got it running, although it runs like **** it sounds mean as hell. I wouldnt mind sharing the video with everyone.

 

Photobucket or YouTube both have video hosting.

 

Here's the poor man's version of a fuel pressure tester, disconnect the pressure line, crank it over a couple times. If it pisses out gas, look else where for your problem.

If you pour a little gas in the throttle body will it start? If no the check those I listed earlier.

I hate to say it but, It might be a bad ECU.

Good luck

 

A bad ECU is definitely a possibility. If it does not run with either starter fluid or by pouring gasoline down the throttle body, then it is definitely elsewhere in the system.

That method of "testing" the fuel pressure is not definitive. A fuel pump may be able to flow fuel, but not provide the pressure required to properly deliver fuel to the engine, even though a TBI motor only requires 8-10psi of pressure to run properly. I have seen this a few times on my dad's old TBI farm trucks.