S-10 Forum banner

1 - 20 of 54 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
I have 94 S10 Blazer 4.3, 2wheel drive, automatic, W engine.

I was getting a whizzing sound from the starter and it would take multiple tries to get a crank. It got progressively worse and it was taking sometimes 5 minutes to get the engine to turn over. But, when I could get a crank the engine would start easily. My daignosis was that the silonoid was bad. I replaced the starter today with an aftermarket from Pep Boys. The ProStart brand starter looked identical to the original.

Now it cranks fine but won't start.

The only snag I had with replacing the starter was I couldn't remove the small wire from the starter before unbolting it. When I dropped the starter it pulled the wire tight until I could get a block underneath it and unbolt the wire. Since it wouldn't start I traced back the wire to the top and opposite side of the engine and looked for damage and checked all the connectors along the way and stuff. I gave a visual inspection on top of the engine and on the bottom where I was working. I checked the fuses inside the cab.

What could have happened? Anybody ever seen this before? Could the new starter be drawing so much current that its not getting any fire to the plugs?
Could anything with the starter be the problem?

Please does anyone have a clue whats going on here??
 

·
It's "Neanderthal"
Joined
·
5,411 Posts
I have 94 S10 Blazer 4.3, 2wheel drive, automatic, W engine.

I was getting a whizzing sound from the starter and it would take multiple tries to get a crank. It got progressively worse and it was taking sometimes 5 minutes to get the engine to turn over. But, when I could get a crank the engine would start easily. My daignosis was that the silonoid was bad. I replaced the starter today with an aftermarket from Pep Boys. The ProStart brand starter looked identical to the original.

Now it cranks fine but won't start.

The only snag I had with replacing the starter was I couldn't remove the small wire from the starter before unbolting it. When I dropped the starter it pulled the wire tight until I could get a block underneath it and unbolt the wire. Since it wouldn't start I traced back the wire to the top and opposite side of the engine and looked for damage and checked all the connectors along the way and stuff. I gave a visual inspection on top of the engine and on the bottom where I was working. I checked the fuses inside the cab.

What could have happened? Anybody ever seen this before? Could the new starter be drawing so much current that its not getting any fire to the plugs?
Could anything with the starter be the problem?

Please does anyone have a clue whats going on here??
When you turn the key to "on" can you hear the fuel pump prime?
 

·
Registered
Joined
·
928 Posts
I doubt the starter and wires and no start condition are related. Also, the wires are generally tight going to the starter, but pulling them a little generally gives you enough slack to drop the starter somewhat before you unbolt the wires.

As suggested, make sure you hear the fuel pump.
 

·
Age: 15 1/2
Joined
·
2,679 Posts
Check the ground wires to the battery. Make sure that you put them back they way they were before removing the starter and are tight.
Check your fuses and make sure that the fuel pump primes for ~3 seconds when you turn the key to run.
Check for spark.
Make sure that you are getting power to the coil.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #5
So far, nobody suspects the starter is screwing up the electrical system.
So, appreciate if you guys can help me through basic trouble shooting.

To listen for the fuel pump, is it under the car (S10 Blazer) on top/inside of the fuel tank?

Haynes manual says there are fuel pump relays on the firewall. Anything to check here.

To check for spark, should I check to see if spark is at the spark plug? Pull a plug out and set it on top of engine/make sure threads are touching ground?
Crank engine and look for arc in the spark plug?

Thanks
 

·
Age: 15 1/2
Joined
·
2,679 Posts
So far, nobody suspects the starter is screwing up the electrical system.
Is the starter engaging the flywheel and turning the engine fast enough to start it?
If yes, then positive volts are making it to the starter and ignition switch, and negitive volts are good to the starter.

Did you disconnect the neg battery connection at the battery before pulling the starter?

To listen for the fuel pump, is it under the car (S10 Blazer) on top/inside of the fuel tank?
It is in the tank. Everytime that you turn the key to run, the computer will power the relay ~3 seconds to make the pump wind up and prime the system with ~60lbs of fuel pressure. If you listen at the gas cap you should hear it. Have a helper turn the key.

To check for spark, should I check to see if spark is at the spark plug? Pull a plug out and set it on top of engine/make sure threads are touching ground?
Crank engine and look for arc in the spark plug?
That would work. I usually have old plugs in my tool box and use a jumper lead to ground the outside of the plug.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #7
I was able to get it started by using starting fluid and let it run for 20 minutes. It started again 30 minutes later. But, after sitting for 2 hours, I had to prime it with starting fluid again.

As for when I first turn the key on, I don't think I can hear the fuel pump lasting for 3 seconds. I just hear the alarm from under the dash. I even had my wife get in and I went to the back of the car and still couldn't hear anything lasting for three seconds except for the alarm under the dash. One time I heard a grumbling noise coming from that area but not lasting for three seconds.

Any suggestions please?
 

·
Age: 15 1/2
Joined
·
2,679 Posts
I've never had to take the cap off, but if there is a lot of noise in the area that would work.
 

·
Age: 15 1/2
Joined
·
2,679 Posts
If the pump doesn't prime, the relay is probably bad.
On the pass side fire wall under the hood, you should find one wire with a connecter on it but not connected to anything. That is your pump test lead.
Near it you should see a bolt with red wires on it (power block). Get a peice or wire and a fuse. Connect one end of the wire to the pump test connector. Hold the fuse to the power block and connect the wire to the other end of the fuse. The pump should run.
Run it for ~5 seconds or so then start the engine. It should start.

Bad relay or wires powering it.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #11
If the pump doesn't prime, the relay is probably bad.
On the pass side fire wall under the hood, you should find one wire with a connecter on it but not connected to anything. That is your pump test lead.
Near it you should see a bolt with red wires on it (power block). Get a peice or wire and a fuse. Connect one end of the wire to the pump test connector. Hold the fuse to the power block and connect the wire to the other end of the fuse. The pump should run.
Run it for ~5 seconds or so then start the engine. It should start.

Bad relay or wires powering it.
Still doesn't start.
I can hear the fuel pump on both scenario's above.
Although, I was expecting a soft humming or whining sound, but what I hear is more of a grumbling sound.
When we turn on the key, I hear the fuel pump but don't think its a full 3 seconds. From under the hood I let it run for at least 5 seconds as you suggested but no luck.
I then sprayed a little starting fluid and it started immediately. Then I took the S10 for a spin and it acted normal. I tried from red light to 65mph flawless. From the preceeding sentence, can I assume that the fuel pump and fuel filter are OK ?

After sitting for a couple of hours, again it won't start. Same as before.

I kindly ask for more suggestions please.

Thanks,
Larry T
 

·
Registered
Joined
·
90 Posts
Still doesn't start.
I can hear the fuel pump on both scenario's above.
Although, I was expecting a soft humming or whining sound, but what I hear is more of a grumbling sound.
When we turn on the key, I hear the fuel pump but don't think its a full 3 seconds. From under the hood I let it run for at least 5 seconds as you suggested but no luck.
I then sprayed a little starting fluid and it started immediately. Then I took the S10 for a spin and it acted normal. I tried from red light to 65mph flawless. From the preceeding sentence, can I assume that the fuel pump and fuel filter are OK ?

After sitting for a couple of hours, again it won't start. Same as before.

I kindly ask for more suggestions please.

Thanks,
Larry T

Check your fuel pressure KOEO, it should belike 60 psi, Im sure someone will chime in with the correct spec.
 

·
Age: 15 1/2
Joined
·
2,679 Posts
Get a set of jumper cables. Connect one to the body and one to the neg battery terminal. Hold the clamps closed real tight while someone tries to start it.

If you disregard that fact that you changed the starter, because the new one works.... The only change that should be considered is disconnecting the battery negitive.

Other things that could cause the problem:
Weak battery
loose positive connection at battery to alternator
Fuel pump regulator
Fuel pump
Fuel pump relay
Fuel pump ground ~check to make sure your rear parking lighs light up real good. They share the same ground strap.
Oip pressure switch only comes into account after the engine is running so that can be elimiated as a cause.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #14 (Edited)
Get a set of jumper cables. Connect one to the body and one to the neg battery terminal. Hold the clamps closed real tight while someone tries to start it.

If you disregard that fact that you changed the starter, because the new one works.... The only change that should be considered is disconnecting the battery negitive.

Other things that could cause the problem:
Weak battery
loose positive connection at battery to alternator
Fuel pump regulator
Fuel pump
Fuel pump relay
Fuel pump ground ~check to make sure your rear parking lighs light up real good. They share the same ground strap.
Oip pressure switch only comes into account after the engine is running so that can be elimiated as a cause..

Get a set of jumper cables. Connect one to the body and one to the neg battery terminal. Hold the clamps closed real tight while someone tries to start it..
I'm not understanding how this could be affecting what seems to be a fuel/priming problem, but I'll try this and see what happens.


If you disregard that fact that you changed the starter, because the new one works.... The only change that should be considered is disconnecting the battery negitive...
I follow you here, I disconnected the ground/negative terminal from the battery, replaced the starter, reconnected the negative terminal.

Other things that could cause the problem:
Weak battery
loose positive connection at battery to alternator..
After I replaced the starter and neg cable, then it wouldn't start so I checked all around the engine to see if I had knocked anything loose as I had mentioned in my original post. Eventually I cranked the engine until the battery ran down. Then I used jumper cables and starting fluid to get it started. The alternator charged the battery so I think battery to ground and battery to alternator are good. Battery seems plenty strong as it gives plenty of cranking.

Fuel pump regulator..
more on the fuel pump regulator please

Fuel pump
Fuel pump relay
Fuel pump ground..
In my last post, I mentioned that today I went 0-60 without any hesitation so was wondering if this is indication that the fuel pump and fuel filter are OK.

Would it be something to also consider that the engine is cold when I am having the problem. Could there be a sensor that is giving a false reading so the computer thinks the engine is hot? But on the other hand, once it starts it runs well.

Not sure if I mentioned this before, when I use the starting fluid, the engine starts immediately. The starter only has to turn for maybe one second and it fires right up.
 

·
Registered
Joined
·
928 Posts
You need to check what he said because once you start the vehicle the engine doesn't need quite as much pressure to keep it running. The vehicle also doesn't need as much fuel when it is warm and the engine is easier to start.

Based on the fact that you can start the truck with starting fluid means that the ignition circuit is OK and the problem lies in the fuel system. The grumbling noise sounds bad, but until you can make sure you have lower fuel pressure than you should, or no fuel pressure at times but do have good connections to the pump you won't know if you need to do an expensive FP replacement.

Just a question out there, but does the $15 fuel pressure guage that HF sells work on our trucks? I saw one for $15 there yesterday that said it would not work with GM throttle body (not what most of us have) and then they had a $88 one that had about everything you could ever need.
 

·
Age: 15 1/2
Joined
·
2,679 Posts
The jumper cable bit is just a quick way to eliminate or fing a ground problem from the battery negitive to the ground bolt feeding the ground to the pump.
It's saved me a lot of time in the past.

Good luck
 

·
Registered
Joined
·
19 Posts
Discussion Starter #18
Thanks everyone for your suggestions. Haven't been able to get back to it yet.
I didn't realize until checking the link that Yogi suggested, that the FPR is built on to the CPI unit. (I knew it was under the manifold but I had thought it was a separate unit ). The reason I mention this is because the CPI was replaced about 13k miles ago but 5 years ago. We had a used car warranty so I had Firestone do the work. I'm pretty sure they got the part from Chevy so pretty sure the FPR was included. Part number 7003002 MPI Assembly was $545.00. The gasket was $24.99. I was thinking if the FPR is under the manifold that it would be automatic to replace it with the CPI even if it were two assemblies.

This couldn't be as simple as a clogged fuel filter could it? I can't recall it been replaced during the 6 years/23 K miles that I have owned it.
 

·
Age: 15 1/2
Joined
·
2,679 Posts
My guess is that the check valve on the fuel pump is giving out, Fuel pump, or the FPR.
More then likely the FPR just like Yogi is suggesting. You should test with a fuel pressure gauge, but if replacing the FPR fixes the problem then it's fixed, and FPRs do get weak with age.
Pull the CPI cover and look for washing. Post some pictures. There are many here that can confirm the FPR from a good pic.

About the starter. The hard start symptom had probably caused the starter to over heat one too many times causing it's demise.
Best of luck.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #20
My guess is that the check valve on the fuel pump is giving out, Fuel pump, or the FPR.
More then likely the FPR just like Yogi is suggesting. You should test with a fuel pressure gauge, but if replacing the FPR fixes the problem then it's fixed, and FPRs do get weak with age.
Pull the CPI cover and look for washing. Post some pictures. There are many here that can confirm the FPR from a good pic.
I'm afraid its probably not the FPR since the CPI was replaced about 13,000 miles ago.

Can the fuel pressure be checked without taking the manifold off and can this test determine which component is bad?
Is there a procedure here in this forum and is there someplace I can buy a reasonably priced guage?

Thanks again for everyones suggestions.
Larry
 
1 - 20 of 54 Posts
Top