S-10 Forum banner
1 - 20 of 45 Posts

·
Registered
Joined
·
33 Posts
Discussion Starter · #1 ·
I have a 95 Chevy Blazer 4x4 that has developed a no injector pulse symptom, but very spuratically. Sometimes it will start and others it will not.. When it won't start, I have to use Starter fluid to get it running, and even after that it will only run for about 10-15 minutes before dying on me.. This has gotten to be very frustrating..

I have replaced the whole ignition system aside from the distributor, the whole fuel system all the way up to the Spider is brand new. I have truly run out of ideas..

It seems weird to me that when I can get the truck running, it stays running til about the time it reaches normal operating temperature, and then starts to shudder and die..

I have been told it could possibly be the Coolant temp sensor, but I wouldn't think that even if the sensor had completely failed, that it would be enough to stall out the motor.. Other possibilities i've heard are a bad TPS, but I don't know why it would kill the motor after the truck was warmed up...

I've been thinkin about gettin another computer for it from the junkyard and seeing if that works, because I am all out of ideas.. and I would much rather not spend a lot of money on a new computer on a whim that it might be the cure..

Any Ideas would be greatly appreciated!
 

·
Registered
Joined
·
8,782 Posts
Pull the ICM and get it tested several times....

Check the pickup coil, also clean the reluctor off.

Check all of the connections on all previousley mentioned stuff....
 

·
i saw what you did there!
Joined
·
3,573 Posts
mess around with the small pink and white wires from coil to ICM/distrib while its running see if engine sputters misses dies etc

injector pulse and ignition are tired together on these

ive found out the hard way in the past

otherwise sounds like a typical dying FP

check for good 12 volts in FP wire in rear ofd truck near tank

it may be droppnig voltage

in which ive had to repair at least a dozen times now by running a whole new frame wire to the tank for the FP, from the front part of the vehicle
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #4 ·
if the fuel pump wasn't gettin proper voltage would that cause the computer to tell the injector not to fire?? I would think that it would still try to fire the injector just with no fuel running through it.. Fuel pump and ICM are both less than 6 months.

Doesn't it seem extremely peculiar that the truck will run sometimes fine for a bit, but is sure to always die, and that it always dies after it warms up?
 

·
Registered
Joined
·
8,782 Posts
If pump voltage drops (or the pump is bad), the output pressure will be low, and the injectors will FAIL to open (no fuel being injected.)......
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #6 ·
right, but the injector(s) would still recieve pulse from the computer, reguardless of whether or not it has ample fuel pressure in the line.. Right?
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #7 ·
Also, the fuel pump, filter, injector spider, are all new.. So are Distributor cap, rotor, ICM, plugs and wires, and Coil..
 

·
Registered
Joined
·
8,782 Posts
Yes, the injector will still get a pulse, but without the pressure from the fuel they wont open and spray, on the borderline they will dribble or have a messy spray.

Also, just because a part is new, doesnt qualify it as good, been there done that too many times. Good luck man!

BTW, what brand on all of your replacement parts?
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #9 ·
yea, but best of my knowledge i'm not having a problem with fuel pressure.. The Spider isn't receiving pulse from the computer..

GM OEM injector spider
Autozone for the rest of the parts..
 

·
Registered
Joined
·
8,782 Posts
Didja replace the pickup coil in the distributor also?
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #11 ·
yup pick-up coils has zero miles on it..
 

·
Registered
Joined
·
8,782 Posts
Does the truck have spark?

Does this truck have a crankshaft position sensor (CKP)?
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #13 ·
Got great spark.. Like I said it's not an issue with spark, because it will fire on starter fluid..
 

·
Registered
Joined
·
8,782 Posts

·
Registered
Joined
·
8,782 Posts
Ha, new I lurked on this page rereading too long! :)
 

·
Registered
Joined
·
13 Posts
Got great spark.. Like I said it's not an issue with spark, because it will fire on starter fluid..
What did you come up with? I'm leaning towards the ecm for my truck, after I replaced everything under the sun, and now lost my negative pulsefor the injector, that I had, the hole time I was diagnosing things like the fuel pump, then spider, then started parts changing the hole ignition except the crank sensor, which I'm going to go out and get first thing today.
 

·
Registered
Joined
·
33 Posts
Discussion Starter · #18 ·
I haven't checked the cat yet.. It does bog down before it stalls out, and it won't let me give it full throttle.. but if my cat is bad or plugged, would any exaust come out of the tail pipe?
 

·
Registered
Joined
·
13 Posts
I thought you said, you were not getting a negative pulse for your injector. Did you determine what the cause of that was yet?
 

·
Registered
Joined
·
8,782 Posts
Some exhaust will come out the tail pipe typically, does the cat glow?
 
1 - 20 of 45 Posts
Top