Any Caddie Northstar Mech's Here?

[Ion]

Having issues and would like to consult with a Northstar mechanic. Thanks in advance!

 

[Ratso]

What issues? I have a tech that has worked on quite a few... When it comes to going "into" one though, we go to the Cadillac dealer, and the ones I sell have been into a couple of times... not cheap either...

 

[Ion]

What issues? I have a tech that has worked on quite a few... When it comes to going "into" one though, we go to the Cadillac dealer, and the ones I sell have been into a couple of times... not cheap either...

It's like this:

I replaced the following:

1. Fuel Pump
2. Fuel Filter
3. MAP Sensor
4. TPS
5. FPR

First start in the morning, car starts right up, or...after car has sat for extended period of time. On the other hand, after running car to store, etc, (where it has not sit for extended period of time), starter will crank excessively before engine kicks in, then when running, will occasionally stutter & buck.

CONCLUSION: fuel is leaking into valves or cylinder after shutting off. If car sits for extended period of time, backed up fuel evaporates, thus alleviating excessive starter cranking. Not allowing backed up fuel to evaporate causes extended starter cranking & black smoke & rough ride.

I believe this issue lies with the injectors, I've replaced about everything else that could cause the problems, plus they have over 100k miles on them. Know of a place in so.cal who re-builds them? The main carb / f.i. guy here in Havasu says there's a place in Longbeach?

 

[24 Sleekenforcer]

I would look at the fuel pressure regulator ,pull the vacumn hose off and have someone turn the key on and see if fuel comes out the regulator. Sounds like your problem.

 

[Big Kahunaa]

can you hear the fuel pump run for 2-3 seconds when you turn the key on

 

[tunnelvision]

bad fuel pump relay?

 

[Ion]

Re:

"would look at the fuel pressure regulator ,pull the vacumn hose off and have someone turn the key on and see if fuel comes out the regulator. Sounds like your problem."

I already replaced it (FPR), AC/ Delco parts
__________________

"can you hear the fuel pump run for 2-3 seconds when you turn the key on "

Already replaced it too and yes, it does prime when key is in aux position.

 

[24 Sleekenforcer]

Sorry missed that. I would hook up a fuel pressure gauge and see if the gauge loses pressure when turned off, it should hold . You could pull the rail up with injectors attached and look for a leak at the injectors and only replace the one's leaking.

 

[rrrr]

Maybe here???

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/

 

[TPC]

bad fuel pump relay?

That's been a common problem on them.

 

[Ion]

Maybe here???

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/

I've been a poster / reader there for a couple years, but thanks for the comment.

Re: pull up the injectors to see which one(s) leak, it's been suggested that if I determine one or more are leaking, they all should be either replaced or re-built, cuz one does not want 2 working at 100%, 3 at 70% , etc...best to have all working at 100%.