I've looked on here and other forums but I cannot seem to find an answer to my issue. I have a 99 Deville (4.6 Northstar), I just bought it because my last car burned to the ground; seller told me that it needed starting fluid to start but ran okay. There were other issues I addressed (clogged EGR tube, fuel filter packed with crap, cleaned TBI, replaced water pump, etc.) But I still cannot get this car to start in its own and it's stumping me. Not a professional mechanic, but my logic says if it's getting spark, has compression (190-200 in all 8 cylinders) and will run once started why isn't it getting fuel at start up? Checked the FPR, but haven't done a pressure check yet.
Sorry for the long post, wanted to give as much info as I remembered.
Thanks for any thoughts and advice.
Cheers all!
Check for codes, sticky at top of forums.
Filter full of crap? Rare these days... Makes me wonder what the pump and strainer/filters in the tank look like. Test pressure next up.
1. If it doesn't have enough fuel pressure to start, how could it possibly run? Test the fuel pressure anyway.
2. If the pump strainer is too clogged to allow enough fuel flow to start, again, how can it run? See above.
3. If the filter was that bad, the strainer must be worse (or ripped or came loose). In which case the filter may need to be changed again and if it is still that bad, you may need to have the tank cleaned or replaced, but as Rod said, it would be rare to be that bad.
That's exactly what I thought Ranger, but didn't think about what's inside the fuel tank. Going to test pressure today, will update the results. Thanks for your time and replies!
Codes from before I started working on car:
1. P0113A IAT sensor circuit high voltage
2. P0603C power control mEmory reset
3. P1111C IAT sensor circuit intermittent voltage
4. P1599C engine stall or near stall
1 and 3 were due to the sensor being unplugged at intake air box
4 car wouldn't idle once it warmed up, fixed this issue and now it idles at or near 650
Fuel pressure is very low. Will build to about 18psi, then go down to 18psi when turning the key to the 'on' position.
When I start it (using ether) it reads at 20psi. I am assuming that the valves in the pump are leaking back?
I just wanted to double check before I spend $300 on a new pump.
It'll run, just like crap and really mess up the computer. My truck FP could get to 50-55 psi at idle, but hit the gas, and the pressure would drop to under 10. But it still ran, didn't have much power for going up hills...
Technically, the spec'd fuel pressure is 45-50 psi, but we all know that the engine will not die at 44 psi. Last time I checked mine it idled at 38 psi so the question becomes, how low can it go? We now have a better idea.
Not directly [as the PCM assumes FP is constant], but when the system goes closed loop, low pressure means lean, which the o2 sensors read, so it tries to put more and more gas in [which doesn't actually work, because low FP]. Computer not happy.
Yeah, she'll idle for days on that pressure. I dropped the tank and pulled the pump, what a nightmare. Not the job, but the idiots that attempted to do God knows what. Only 3 bolts holding tank up and one of those were halfway out, they bent the large nut so only 3 of the tabs were locked in and the cut the wires to the pump (inside the assembly) above AND below the connector which they used butt connectors on one splice and left the others twisted together without anything else....
Anyway ordered a new pump and hope it is the answer to the non starting issue, thanks Ranger and to all of those that gave time to offer their assistance.
If you ordered the entire pump assembly - pump, casing, fuel level sender - there's a good chance that it will include the new, HD wiring pigtail that gets spliced into the existing harness. Wiring diagrams come with the pump assembly. The new HD connector has 3 or 4 flat blades instead of pins. RockAuto - Airtex, DELPHI, UltraPower, AC Delco - all the same assembly.
This pic is for a 2000 and later assembly - yours may not have the tank pressure sensor on the top - that might be on the tank top itself.
Thanks submariner, I think the only difference is the vent is attached to the pump assembly and not the tank.
By the way, I have read a lot of material on this site, it has been an invaluable reference of hands on information by experienced mechanics, home mechanics, people looking for information and the others. I, as well as thousands of others appreciate all of the time and knowledge shared with us. Thank you verymuch!
UPDATE: New pump installed, 40-43 psi and no change. Will not start without either ether or gas sprayed in the intake (I spray at the air filter) but will run. It has a dead spot right off idle, but will "catch up" and rev into the higher rpm's.
I don't know what to check or look for anymore.... left thinking my first Cadillac is going to be my last.
and when in WOT if the injectors are leaking down or leaking it will not be dumping gas all the time. Just a check but not knowing what all he has tried and tested just offered it to him to see if it worked sure wont hurt anything.
UPDATE: The problem was in the pump assembly. The hose that goes from the pump motor to the outlet wasn't staying on under higher pressure, so it would hold at 20 but would bleed off at the pump outlet because the hose wasn't tight enough.
Man, something so simple yet caused me to doubt any troubleshooting skill I have.... glad to have it fixed.
THANK YOU ALL FOR YOUR HELP!!!
Gary N.
I'm sure I will be back here, as this Caddy has other issues I will be addressing!
Don't feel bad friend with similar issue on k1500 threw about a grand at it. Turned out was the relay for pump didn't even need replaced just cleaned and spread terminals slightly
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