Tranny replaced, now it wont start!

[smsrobertks]

Originally Posted by djd99

I had the same problem after replacing my transmission, when the job was done it wouldn't start. I had to relearn the security system and then it started right up. You might want to give it a try. I found the procedure on one of the threads on this forum. Your situation could be a little different but worth a try at least.

the relearn proceduer should be {turn key to the run position make sure the security light is on.wait atleast 10 mins.} id go 15 or 20 just to be sure.that worked on my 99 yukon and my wifes 2001 blazer. after 10 mins or so the light will go out by itself,that means its reset. yes its worth a try.

[smsrobertks]

Originally Posted by GMCjet52

Update!!!

The Check engine light (service engine) does not come on at all with the key is the on position. What does this mean?

I did scan the vehicle----no codes.

ok! when u scanned the computer and got no codes.did u mean it canned and said no codes or did the 2 of them actually communicate with eachother?

[bmoody1981]

Originally Posted by GMCjet52

I should also mention that before any tranny work was done the Blazer wouldn't start under it's own power with a brand new battery. The only way it would start is with a jump.

I had this problem a few days before starting the tranny work.

Which wires on the fuel pump plug do I need to check for power?

I noticed the fuel pump wires have been messed with, they have been spliced.

Well the wires being spliced may not be a bad thing. Blazers, Tahoes, S-10's and Suburbans have had issues with the wiring harness and it sounds that someone may have already been in there and replaced the problem.

As for what wires to test I'm not sure of the color of the wires but find you a good solid ground and with the key on you should have one wire that is hot from the ingnition switch. BTW is yours the 3 prong plugin or the 4 prong plug in?

[GMCjet52]

Originally Posted by smsrobertks

the relearn proceduer should be {turn key to the run position make sure the security light is on.wait atleast 10 mins.} id go 15 or 20 just to be sure.that worked on my 99 yukon and my wifes 2001 blazer. after 10 mins or so the light will go out by itself,that means its reset. yes its worth a try.

The security light goes out after a few seconds with the key in the on position.

When I scanned it showed zero codes, it communicated normally.

[GMCjet52]

Originally Posted by GMCjet52

The security light goes out after a few seconds with the key in the on position.

When I scanned it showed zero codes, it communicated normally.

Originally Posted by bmoody1981

Well the wires being spliced may not be a bad thing. Blazers, Tahoes, S-10's and Suburbans have had issues with the wiring harness and it sounds that someone may have already been in there and replaced the problem.

As for what wires to test I'm not sure of the color of the wires but find you a good solid ground and with the key on you should have one wire that is hot from the ingnition switch. BTW is yours the 3 prong plugin or the 4 prong plug in?

I'll give this a try tonight. The fuel pump has two plugs on top, I believe one has 3 wires and the other has more.

On a side note: I called the parts store and they want $367 for a fuel pump, the dealership want $567

[djd99]

Originally Posted by GMCjet52

I'll give this a try tonight. The fuel pump has two plugs on top, I believe one has 3 wires and the other has more.

On a side note: I called the parts store and they want $367 for a fuel pump, the dealership want $567

If you have a carquest nearby they'll sell you one for $300 that's a delphi... Also Advanced auto can order delphi's but most of the counter guys do not know this you have to talk to a manager. I found this out personally when I told a friend of mine I got my pump from carquest and he said there counter guys don't know all the parts they can get, so to prove a point he called his suppler and he could of sold me one for 275 with a discount. Now I no I should go directly to him next time.

[GMCjet52]

Ok,

I checked for voltage at the fuel pump. On the big grey wire I got 12v for a few seconds with the key forward. When the blazer is cranking over its getting 12 volts the whole time.

No fuel pressure, can't hear the pump running.

Is this case closed.....Bad fuel pump?

[djd99]

Originally Posted by GMCjet52

Ok,

I checked for voltage at the fuel pump. On the big grey wire I got 12v for a few seconds with the key forward. When the blazer is cranking over its getting 12 volts the whole time.

No fuel pressure, can't hear the pump running.

Is this case closed.....Bad fuel pump?

How is the ground? If you have a good ground and power to the pump it has to be a bad pump.

[djd99]

Originally Posted by blazes9395

No spark/no fuel = No start.

If you have no pressure, then you'll have to re check all your connections under the truck, make sure you didnt pinch any wiring when you were installing the transmission. Having the battery disconnected for a long period will not hamper it starting once reconnected.

No SES light is an indication something not cennected or is shorting. Check your underhood fuses for ignition and PCM.

Also I disagree with this post When I did my transmission my battery was disconnected for over a week and when I did get it finished my truck wouldn't start. I had to relearn the security settings to get it to fire up.

[blazes9395]

Originally Posted by djd99

Also I disagree with this post When I did my transmission my battery was disconnected for over a week and when I did get it finished my truck wouldn't start. I had to relearn the security settings to get it to fire up.

Having the battery disconnected for a certain period of time should not cause the truck to not start. You can and most likely will lose adaptive and learned memories, but core programming/operating functions will be there. As for the security function, its a possibility that it could loose this, but highly unlikely. I have had security equipped cars disconnected for months and have had no issues restarting them. On the other hand, I have had a car loose its PCM because I disconnected the alternator to install a new one without disconnecting the battery.

Getting back to this thread, if you have 12 volts koeo and then 12 volts when turn over the engine, if the ground is good to the pump, like djd99 mentioned, then you have nothing more at that point but the pump.

[GMCjet52]

Well, I guess this wraps it up. I can't afford to buy a fuel pump right now, I just dropped $600 on the tranny.

I'll push the blazer to the back yard for now and use it for a garden shed.

I'll let you guys know how it turns out when the economy picks up and I find a job. My bicycle will get me where I need to go for the time being.

Thanks for all the advice.

[evo-00]

Spliced wires prob means the pump was replaced at least once. It's recommended that the plug is changed for a new pump. I don't know why but the replacement plug is diff than the orig. one.