1992 Oldsmobile Bravada, won't stay running, starts then dies,new fuel pump,filter, spark good,power,help?

Question

Great car when it runs. Driving down the road it just dies, now it only starts and dies. Charging system good, fuel system, lines, good, no check engine light, Injectors do not appear to be bad, new pcv valve, ran Slick 50 through to make sure no residue, mechanic is baffled, taken manifold off, cleaned and cleared all lines, what is left or has been missed? Car has low mileage and well taken care of. Started out by just dying while driving, seemed like after car would get warm and then after it sat for 30 minutes or so it would start right back up and go again, sometimes dying, but not all the time. Now can't keep it running for long, fuel is flowing. Need help with how to figure this out without spending a zillion dollars, already have spent almost $1500.00 in fuel system repairs. Mechanic is at a dead still. Please help.

Answer 1

Has anyone checked for vacuum leaks? Such leaks can, and do cause just what you are asking about.

Answer 2

First off: A engine needs three things to run.

Fuel
Spark
Air

If the engine is in good mechanical condition, then one of these items is missing.

Check the ballast resister.
Check the coil.
Check the coil wire from the distributor to the coil.
Check the spark at the spark plug.

Make sure the air filter and intake are clean. Could be a wasp nest or bird nest in it. If the filter is ok and the intake is open then you can mark off it as the problem. Check the vacumn of the engine. If it is low, something is leaking to make the vacumn low OR the catlytic converter or muffler is stopped up......OR someone could have driven a irish potatoe up your tail pipe. (An old joke back when I was a kid) With a stopped up tail pipe, the engine will start and quickly die because if it can't push exhaust gas out the tail pipe it can't pull new air in to run on.

Doesn't your engine have the intake carburator type injection system? Whether it has one injector or more, do this.

Put some gas in a VERY small container. Remove the air breather. Have someone crank the engine over while you slowly pour some gas into the intake. Be VERY careful in doing this!! If the engine starts up, keep dribbling a little gas into the intake. If the engine keeps running until you stop pouring gas, then the problem is most likely in the fuel system. This might be the gas tank is stopped up, the fuel pump is not putting out enough pressure or volume. Check the fuel pump pressure and volume at the engine. The fuel filter may be plugged up. Change it. There used to be a small filter screwed into the carburator type injection system. If you have plent of fuel flow and pressure to the engine, then the problem is probably electrical.

Electrical. Check the computer to make sure it is telling the injector/s to open and close. This will require a mechanic with testing equipment

Good luck. Pops

Answer 3

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RE:
1992 Oldsmobile Bravada, won't stay running, starts then dies,new fuel pump,filter, spark good,power,help?
Great car when it runs. Driving down the road it just dies, now it only starts and dies. Charging system good, fuel system, lines, good, no check engine light, Injectors do not appear to be bad, new pcv valve, ran Slick 50 through to make sure no residue, mechanic is baffled, taken manifold off,...

Answer 4

You need to take the car to a different mechanic. There are many things that would cause the problem that you describe but a detailed step by step check using a "starts then stalls" flowchart should uncover the cause. There are a couple of things that are easily checked that you didn't mention as having been checked. First, unplug the MAP sensor and start the car, if it stays running, replace the sensor. Also unplug the distributor bypass connector and if the engine starts and runs, replace the distributor pick-up coil>

Answer 5

you dident say if vacume lines were replaced. if not them change them. its very cheep.
could be timing chain is starting to go out or timing gears are slipping. its either the carb the vacume lines or the timming.
or the float in the carb is bad. id recheck the gap on the plugs it could be that the mech trusted the preset plugs and dident double check the gap. always double check the gap on your plugs and never never belive them when they say they are pre gaped. did you replace the distcap and points.
it really sounds to me like you have either a carb problem or vacume or fuel problem.
i just reread your post and noticed it has injectors. make sure the o rings are new and if you havent removed each injector and cleaned them then do so its really easy and change the rings at the same time. and if anyone tells you the o rings are 80 bucks then go to oryle or smoeplace else. autozone told me o rings for my van were 80 each and i went to oryley and got the whole set for 5 bucks and i could have improvised with basic plumbing o rings if i had to. make sure that none of your spark pluges were cracked or broken during reinstall. **** happens and make sure the wires are seated and if need be check the wires and make sure they are getting spark. do this by removing the plug and putting it in the wire and have someone turn the key while you hold the plug end close to a peace of ground metale like the alt housing bracket ect be very carefull to hold only the wire and dont touch any metal wile doing this. it really hurts. i know iv done it. a sparkplug shock will put your morning coffee to shame.
be carefull and good luck. and obouve all if you have no idea of what your doing while messing with sparkplugs then let a greese monkey do it. we are really good at it.

Answer 6

there's a good possibility that you got a bad fuel pump for it ,this happened to me and i spent a lot more than you have on a car similar to that ,the reason i didn't suspect the fuel pump was that it was running and seemed to have good fuel pressure,but it didn't really have ,you could also have a bad pump relay for it,that will cause the exact same thing to happen ,your getting in deep like i did,i finally did figure it out that i had got a bad pump,even though it showed to be good it wasn't,you also need to have an electrical check done in it,those cars had some problems with electrical issues.it may take a good mechanic some time to figure it out,good luck with it.

Answer 7

Your issue is caused by poor oil choices. VALVOLINE a very popular oil is a SLUIDGE MAKER and not worthy of a lawn mower. Check vacuum at PCV valve where goo and sludge dwell. Use AMSOIL POWER FOAM to dissolve deposits in THROTTLE BODY and IDLE AIR CONTROL VALVE. Add half can of PPWER FOAM to your oil and drive for one day. THEM USE ONLY AMSOIL OIL Mpbil One0W-30 or PENNZOIL ULTRS EIRO oil. Change it once a yearONLY. Also use AUDI or BENZ coolantONLY. Once you have showroom clean t body and IAC and good PCV your issues will resolve. Also remove junk AC DELCOpligs that fail in testing and imstallBOSCH or Denso IRIDIUM plugs to gain 20% in power and fuel savings. POWER WASH engine bay with GUNK ORANGE engine cleaner to remove road salt and debris from engine compartment. NP MORE PRESTONE OR WAX BASED JUMK OIL! An AMSOIL oil change is good for one full year or 25k miles. Good luck and STOP WASTING MONEY on poor oil choices. DEXOS oil is okay.

Answer 8

This sounds like an ignition or ignition control problem. On older Old's they had an ignition control module which wouldn't necessarily show up in a scan. If your mechanic can find a working one (off a known running engine) and tried it, this might reduce some of the guess work.

Answer 9

When you changed the fuel pump, did you also change the inline fuel filter?..if you did, then check the fuel lines coming from the top of the gas tank, you might have a small leak. Have you replaced the module under the coil packs...heat makes them just quit, and after they cool, they work again..then again, it could be in the ignition switch...Is the security light coming on??? email me back.

Answer 10

What mileage ? this could be a leaky head gasket . Or worn out piston rings or a myriad of other things.Was the car idle for a long time ? In that case Gasoline is too old.

Answer 11

You didn't say this. Check the computer. A microchip might be faulty or is giving bad information to the engine mechanism.