95 4.3 wont start after engine swap

[sucker4ablazer]

Well here we go again! put a slightly less used engine in my blazer, used my intake, never touched the injector or nozzles since it was working on other engine...

now, have good compression, have 62psi on fuel rail and have spark.
checked voltages, all there and good. checked pulse from crank sensor.. its good.

for some reason ive got no fuel coming from injector. Is it possible it just decided to stop working, or am i overlooking the obvious?

thoughts or suggestions anyone? (other than pull it out of garage and light a rag in the gas tank)

[sucker4ablazer]

OK so after several hours of research and wire chasing and partial disassembly I now know the injector has 0.00 resistance. with connector unplugged I have batt voltage on one side... but plug back in and backprobe and there is 0.00 volts.
Leading me to believe the injector is bad.....

NEXT QUESTION.... hopefully someone can save me from being on the net half the night.

Since I have a good 96 computer, wiring harness and intake with all the goodies.... can I just swap the setup out and save a couple hundred bucks on that silly injector?? Or am I looking at a wiring nightmare?

[sucker4ablazer]

Wow 178 views and NO input!?!?!?
WELL..... for those interested I did the research. It takes the heads, intake, wiring harness and computer. Provided the 2 vehicles are optioned the same, the vehicle wont know the difference~

the real kicker.... its 3 times the work, but less than 1/4 the cost of the damn injector for the 95!

[j cAT]

Originally Posted by sucker4ablazer

Wow 178 views and NO input!?!?!?
WELL..... for those interested I did the research. It takes the heads, intake, wiring harness and computer. Provided the 2 vehicles are optioned the same, the vehicle wont know the difference~

the real kicker.... its 3 times the work, but less than 1/4 the cost of the damn injector for the 95!

with the ignition on,,,, engine off , 12volts is at the injectors at all times. the PCM grounds the injector coil return side , causing them to open by way of the pcm input signal from the crank sensor.

since you replaced the engine my guess is you damaged the wire harness /connectors/failed to connect the grounds etc/things like that.

with what you did this is not going to get much input because your the only one who knows what you did. this is not like the engine just wont start . to much messed with to give good repair input.

with a good shop manual and a good fully capable volt/ohm meter you should be able to fix this with no problem.

[sucker4ablazer]

You are correct in the fact that I'm the only one that knows what I've done. It's comical to me that some people here are looking for help and can't hardly form a complete sentence and get tons of "try this, check that" but some come here and can say ok here's where I am, this doesn't make sense and posts are ignored. I'm not the only one i've seen.
I've solved this particular problem with the help of the internet and a couple other more helpful sites.... good luck to the rest of ya!

[j cAT]

Originally Posted by sucker4ablazer

You are correct in the fact that I'm the only one that knows what I've done. It's comical to me that some people here are looking for help and can't hardly form a complete sentence and get tons of "try this, check that" but some come here and can say ok here's where I am, this doesn't make sense and posts are ignored. I'm not the only one i've seen.
I've solved this particular problem with the help of the internet and a couple other more helpful sites.... good luck to the rest of ya!

it looks like you got no advice from this forum other than my comments.
being a 1995 vehicle its getting too old for members to be on top of issues on such an old vehicle.

you did solve your problem by yourself and this is good.

so what was the cause of your failure with this ?

[53bruce]

there is another test of the injecter you can try, but you need to be carefull about how you do this.
when i look at injecters, i have tried this method and its does find stuck injecters..
connect a fuel pressure gauge to the fuel rail.
turn ON the ignition, but do NOT try to start the engine.
the fuel pressure will be about 60 psi.
now, turn the ignition OFF. Fuel pressure should remain steady.
now,l disconnect the injecter wiring at the top. this will expose all 6 injecters electrical wires.
take 2 fine jumper wires and connect to one of the injecters.
now make sure you have no gasoline fumes around!
quickly tap and disconnect the 2 jumper wires to a 9 volt battery.
if the injecter is any good, the fuel pressure will drop when the injecter is open. note , the fuel pressure must be between 50-60 psi to do this test.
try this on all injecters, turn the ignition on from time to time to get the fuel pressure back up if it drops too far.
of course, you need to use some common sence as connecting the battery will have some small sparks.so dont do this if you smell any gasoline fumes!

fuel injectors are nothing more that a fast acting valve.
if you find they are all working, then I agree witha previous post that you need to look at the wiring and grounds.

[53bruce]

there is another test of the injecter you can try, but you need to be carefull about how you do this.
when i look at injecters, i have tried this method and its does find stuck injecters..
connect a fuel pressure gauge to the fuel rail.
turn ON the ignition, but do NOT try to start the engine.
the fuel pressure will be about 60 psi.
now, turn the ignition OFF. Fuel pressure should remain steady.
now,l disconnect the injecter wiring at the top. this will expose all 6 injecters electrical wires.
take 2 fine jumper wires and connect to one of the injecters.
now make sure you have no gasoline fumes around!
quickly tap and disconnect the 2 jumper wires to a 9 volt battery.
if the injecter is any good, the fuel pressure will drop when the injecter is open. note , the fuel pressure must be between 50-60 psi to do this test.
try this on all injecters, turn the ignition on from time to time to get the fuel pressure back up if it drops too far.
of course, you need to use some common sence as connecting the battery will have some small sparks.so dont do this if you smell any gasoline fumes!

fuel injectors are nothing more that a fast acting valve.
if you find they are all working, then I agree witha previous post that you need to look at the wiring and grounds.

[sucker4ablazer]

Originally Posted by j cAT

it looks like you got no advice from this forum other than my comments.
being a 1995 vehicle its getting too old for members to be on top of issues on such an old vehicle.

you did solve your problem by yourself and this is good.

so what was the cause of your failure with this ?

Yes Problem was solved.... 2 identical connectors with dirty/greasy wires were found to be in wrong places. After some cleaning and wire chasing I swapped the 2 plugs and it started right up.

[j cAT]

Originally Posted by sucker4ablazer

Yes Problem was solved.... 2 identical connectors with dirty/greasy wires were found to be in wrong places. After some cleaning and wire chasing I swapped the 2 plugs and it started right up.

this is common . when replacing the engine you should make a diagram and record the layout as you remove the engine. marking the connectors if it appears that the could be installed wrong.

[sucker4ablazer]

Yeah I just plain missed it. I looked and it didnt seem like they were the same at the time so I didnt feel like labelling. It was just dumb luck that when I laid that harness back down on the driver side those 2 fell the wrong way and being in a hurry I just plugged em in.
On the bright side I learned a couple new testing procedures and know that a few parts are good and new! LOL

[j cAT]

Originally Posted by sucker4ablazer

Yeah I just plain missed it. I looked and it didnt seem like they were the same at the time so I didnt feel like labelling. It was just dumb luck that when I laid that harness back down on the driver side those 2 fell the wrong way and being in a hurry I just plugged em in.
On the bright side I learned a couple new testing procedures and know that a few parts are good and new! LOL

this is why your post did not get much of a reply. lots of wire/connectors that do get damaged with this work .

hard to say what you did that caused this problem.

thanks for the reply as to what the problem was. good luck.