1991 Eldorado Touring Coupe, 4.9l v8

[BodybyFisher]

2 hours ago, sonjaab said:

Plenty of warning on this on the GM truck and camaro/bird forums when diagnosin' a

hard hot start or rich idle, and bad FPR problem.  Also removal of  the "beauty cover" on a running engine.

What it does is spike the fuel pressure, exactly what is needed to induce the diaphragm to leak. 

I am not going on a trip with it off, I am not going to the grocery store with it off nor am I picking the kids up from school with it off.  

It is off less than 30 seconds, start engine, walk around door, lean over hood, pull vacuum hose, rev engine, see fuel (Y or N)?, put hose back on.  Diagnosis complete.   I have also pulled the vacuum hose to show maximum fuel pressure while testing fuel pumps.

I recently installed a holley 4bbl carb, electric fuel pump and regulator on an 89 chevy 350 that previously had TBI.  How is the fuel pressure set?, with a fuel pressure gage attached, pull vacuum hose off regulator, set regulator for 5 to 7 lbs reattach vacuum hose, now as engine is revved, fuel pressure increases to the preset max. 

The difficulty becomes diagnosing the northstars (93/94) where the regulator is inside the intake plenum a leaking regulator causes severe backfires and harder to diagnose.

This procedure has been used here since 95 without hesitation until this from GM truck and camaro/firebird forums.

[91 Eldo TC]

Ok. Im going to check the FPR 2morrow. That E046 code came back on. Fuel economy dropped and im experiencing some power loss as well. Im thinking the code is bad plugs and wires. Ir maybe an O2?  Could the E046 be caused by a faulty PFR? Im pretty sure the starter needs replacing, Its getting super hot, and once it cools down, she starts right up. I actually put ice on it to speed up the process and it worked.I bought a new starter and tried to put in on but couldn't get the darn exhaust off. Im gonna pay someone else to do it I guess.  So i think the starting problem will be solved once the starter is put on. 

[BodybyFisher]

Here is a thread you should look through 

 

[BodybyFisher]

Look through this one also

 

 

[BodybyFisher]

I suggested the one minute fuel pressure regulator test because of 1) the hot start symptom and 2) the fuel smell you reported.  For me, testing the regulator is a no brainer it's like checking to see if the ash tray is full, must check to eliminate it from being a problem.   Again, the technique was recommended by the 'guru' who was an engineer on the 4.9 and NS design teams.

Another quick test is fuel pressure, put a gage on the fuel rail and you eliminate the pump and fuel filter.  

However, the E046 is a left /right fuel imbalance.  Anotherwords, something is impacting one bank but not the other.  An imbalance can be caused by too much fuel or too much air (vacuum leak).

This is what I would do, I would check every vacuum hose and plastic fitting on the intake for looseness or cracks.  Don't forget the plastic adapter at the brake booster, although I think that would impact both banks. 

I would clean the EGR valve by taking it off, clean it its pindle by turning it against its seat, spray it with carb cleaner (only the valve part NOT the top) and stick some small brushes into it to loose up carbon (wear a mask and rubber gloves). While it was off I would spray carb cleaner into the 2 passageways under the egr and let it sit, I would use a hanger to 'rod out' the 2 pipes sticking up in the throttle body and use compressed air to blow out the 2 passageways into a rag, so the carb cleaner doesnt blow all over the place.  NOTE: the 2 passages under the EGR go to the 2 pipes when you look into the throttle body.  You may see crud built up on those 2 pipes.  When you spray compressed air into the pipes under the EGR, it will exit with the carb fluid via the pipes in the throttle body, cover the TB with a rag.

While EGR is off, I would raise the fuel rail and support it up so you can see the ends of the injectors.  Don't touch them or attempt to clean them.

I would turn the key to ON (NOT START) to pressurize the fuel rail and observe the injectors to see if any drip fuel.  Any that drip need replacing.  This might be where your fuel smell is coming from.

Keep in mind that when the E046 is current the engine runs in open loop when means it is running very rich as if the choke were on in the old days, so the open loop condition could be the source of your fuel smell.

When you reinstall the fuel rail use new injector seals on the injector bottoms and use a new EGR gasket.   Use non petroleum based, O2 sensor safe, light lube on the injector seals, don't overdo it and NEVER touch or clean the injector tips.

Use a bottle of Techron on a full tank of gas per the instructions on the Techron bottle to clean the injectors and intake valves.

That is where I would start.  Read the 2 threads I posted above for background info and please post your results and findings.