It starts fine when cool,but after driving it and it sits for 30 minutes,it is very hard to start,have replaced egr valve,map sensor,fuel pressure regulator,fuel filter,and ecm.
Just because you replaced the fuel pressure regulator does not mean it is working correctly; which is the most common cause of your problem. Hook up a fuel pressure guage and watch what happens when you are starting it cold - it should go up to about 47 PSI and once started it should read between 40-47 PSI, then when you turn the engine off: Does the pressure drop? There is a check valve built into the fuel pump also; that can be faulty and if the pressure is generally reading low and the check valve is bad- this can also create your problem. We have run into this before also; When the fuel pump is cold the internal pump seals are sealing great, but after a period of running time the pump seals lose sealing power and if you try to start it again it will be hard to start. The biggest thing with this situation is getting the fuel pressure readings at the following points of time:: Start-up, running cold, running at normal operating temp, engine off, engine re-start.
Pete/ Bambenek Auto LLC
Testimonial: "THANKS FOR YOUR HELP.ECM WAS FLASHING DIFFERENT CODES,THAT WAS WHY I REPLACED THE PARTS.SO I GUESS THE NEXT THING TO DO WOULD BE TO CHECK THE FUEL PUMP.COULD COIL PACK CAUSE THIS AND IF SO HOW DO YOU CHECK IT?I JUST BOUGHT THIS CAR AND THERE WERE SIGNS THAT SOMEONE HAD BEEN IN THE SAME AREAS I WAS HITTING.I CANT AFFORD TO KEEP THROWING MONEY IN THIS."
You should not have to keep throwing parts at the problem, proper diagnostics is the key to this problem. I will be more than willing to help you further if you need it. Pete
Mike, What codes were they so I can evaluate what is going on.
Also, the first thing is to check those fuel pressures as I suggested, It makes a HUGE difference as to what is going on with the fuel system. In this manner we can isolate whether its a fuel or ignition problem.
FYI: if a coil pack was bad you would get 2 cylinders misfiring, because each coil pack handles 2 cylinders.
What engine do you have in this, hopefully its not the 4 cyl, those are a nightmare - I know, our shop has had to deal with these in those years. The 1988-1991 were the worst for those engines, which is referred to as the "Quad 4". In 1992 they finally dropped the compression ratio to eliminate head gasket problems. Also there were rare occasions that an ignition module would heat up and create hard starting. But before I go too far, I really need to know which engine you have. 4-cylinder (2.0, 2.3, 2.5) or V6 (3.1, 3.3, 3.8)
SORRY ITS THE 3.1,CODES WERE EGR VALVE,MAP SENSOR,O2 SENSOR,AND ELECTRONIC VACCUM.I JUST PUT A DIFFERENT ECM ON AND AS OF NOW THERE IS NO CODES,BUT STILL HAVE THE HARD START PROBLEM.THE CAR RUNS GOOD ONCE IT IS STARTED.THANKS FOR YOUR HELP.
I DO NOT HAVE A FUEL PRESSURE TESTER AT THIS TIME.I WILL HAVE TO GET THIS DONE.I HAVE STOPPED WORKING ON IT FOR NOW SO AS TO NOT WAST ANY MORE MONEY ON THINGS NOT FIXING IT.
Good decision, lets not spend anymore money until we isolate the problem (if we did this in our shop (throw parts at it) - we would be out of business by now LOL). Once you get those pressure readings, I then can determine where to go from that point. Take care Mike and let me know.
Thank you Sir, You have been very helpful.Sure its obivious i am not a mechanic i know just enough to get my self in trouble.Should have left this to the proffesionals such as your self. i am on a limited budject right now and trying to save money.I will get readings and get back with you.Thanks again.
Your welcome, and if there is a delay for me to respond, please excuse it, I'm just doing this in between shop operations here. I think everybody needs a break once in a while from shop prices - so I do this once in a while. I'm also an expert at JustAnswer.com occasionally. Glad to help out.
My motto is "what goes around-comes around", I have helped just about every other kind of professional that I we have done repair for. Everyone is so happy that those others will also help me out with what I don't know, makes for a good working relationship. Take care, and I will wait to hear back from you......Pete
i borrowed a fuel pressure tester and the end will not fit the connection so i will have to find a connector that fits before i can get readings.It is now flashing a code 33.Was wondering if the crankshaft position sensor or throttle postioning sensor could be bad? Thanks for any input.
Code 33 is a "MAP sensor signal voltage high", this is not normal, its usually low voltage. Computers run on +5 volts, if the voltage is higher then many problems can develop. You should check the B+ wires on other components to see if they are reading high, if so, then the ECM has an internal circuit problem. It still can be an ECM problem allowing over voltage to the MAP sensor in the internal circuitry of the ECM. It is very time consuming and in depth to diagnose and would be beyond the scope of this medium (web posting) for diagnostics here.
You did state earlier you replaced the MAP sensor. Unless you got a faulty new one, which does happen - trust me on that one (we have installed thousands of sensors and it happens.
You know......Do you have any vacuum leaks, they will cause major problems as you describe, also.
Here is the circuit:
Diagnostic aids also state that:
These captures are hard to read, if you have an e-mail, I can send them to you.
[email protected]. i just went to parts store and they showed code was an coolant temperature sensor.i guess i was wrong tried to read with a paper clip.thanks
Ok, yeah most of them will read it for you.
A coolant temp sensor will create a rich mixture and fouls out plugs easily. Theres a start. Let me know if you need more info.
ok thanks again.you have been very helpful.
The paper clip works just fine, remember the first 2 flashed numbers will be 12 indicating start of code fault display and the last 2 will also be 12 to tell you its the end of code transmission.
ok,havent looked yet,but where is the coolant tempature sensor on the 3.1?
There is actually 2 of them, one is for your guage and the other for ECM information. The one you are wanting to replace should be a 2 or 3 wire connector and its located: If you are in front of the car looking back into the engine compartment, it will be just forward of the throttle body and down in the valley, it will be angled towards you at roughly a 45 degree angle. I'll see if I have a picture of its loacation.
Picture looks bad, it will be right next to the thermostat coolant outlet.
Look at the "B" location, thats the one.
is it by thermostat housing? i see that,its pointing towards firewall.if thats it it looks like they gave me wrong one.the plug is too small
Doesnt matter thats for a buick in the image, its in the same location.
Heres another:
And one more pic.
Hope that helps.
They gave you the sensor for the guage if its only one prong.
The one for the ECM will have 2 prongs.
Add a CommentI dont even want to begin to tell you where that one goes, its in a stupid place.
I dont even want to begin to tell you where that one goes, its in a stupid place (the one with a single green wire going to it).
Tell the parts people its the other coolant sensor.
Heres a good reference and even shows video to install:http://www.1aauto.com/1A/coolant-tempera...
Just highlight the whole address and put into your search bar.
Sent you an e-mail with the link......
I'm only following what you want to do at the moment, we kind of veered from the original problem. But we must correct one thing at a time.
i got the right one,the plastic housing was broke,i dont think it was ever on there since i got the car.if thats the case would that be the cause of my oringal problem?
you dont know how helpful you have been.i really do appreaciate it and would recommend you to anyone.wish you were in indiana,i would bring my car to you anytime.its hard to find an honest mechanic around here.
Thanks for the thoughts, just trying to help. We will get it solved. There used to be another common problem with this vehicle: The ECM would get an internal failure in which the "Quad Driver" (an internal "IC" Integrated Circuit) would fail creating an over-rich mixture and rough running. It was hard to diagnose, because a computer cannot diagnose itself. Just food for thought of common problems we have experienced throughout the years with that era of vehicles.
i put a different ecm on there, could the cts be the problem from the start?the plastic housing on the cts was broke and i dont think it was ever even plugged in.i'm going to put the new one on now,will see what happens. thanks again.
If the CTS were bad it would give a continuous rich condition because the ECM sees the engine as cold all the time and in effect richen the mixture all the time. This would create fouling of the spark plugs which in turn could give you a miss in the engine, creating hard starting.
The short answer, maybe. Have you replaced the spark plugs, I don't see that in the posts anywhere?
Ok Mike, simetimes it takes a jolt (LOL) to find things wrong. I think you probably found your culprit. I'm up in SE Minnesota (heck of a cold winter this season), well I was glad to help you (shake your hand), let me know if you need anything else, glad to help out.....................Pete
Hi Pete,i'm back the 1991 lumina is starting fine now and seems to run a lot better,now after driving it and getting at operating temp while going do9wn the highway and i get on the gas it either stalls or dies.It will restart but it has no power then it goes fine till i get on the gas.Any ideas?
When you took a fuel pressure reading, what was it while the engine was running?
Anyway, Mike, it looks like you had several problems at the same time.
Hi MR.Bambenek, i still havent got fuel pressure readings,going to this week.Your right i think i had a bunch of things going wrong.The car had set for quite awhile due to gentleman going in nursing home and i bought the car from his son.IT RUNS AND STARTS GOOD NOW EXCEPT WHEN YOU ACCELERATE AS IF TO PASS SOMEONE THEN IT STALLS OR DIES.I'M SURE YOUR RIGHT WHEN YOU SAY FUEL PUMP.IDK.SOMEONE TOLD ME CRANK SENSOR OR THROTTLE POSITION SENSOR.I'M NOT SPENDING ANYMORE MONEY TILL I'M SURE OF PROBLEM.THANKS FOR GETTING BACK TO ME.HOPE YOU HAD A GOOD EASTER. MIKE
It was OK, except for the rain, thanks. Hope your Easter went well. Yeah, lets get those pressure readings, so I can advise you about them. Don't throw in any parts until we get to the bottom of the problem (diagnostics) , Its easy for anyone to say - throw that in-throw this in- its not their pocketbook. Take care........Pete
Good Morning,I got the pressure readings this morning.At operating temp it was 34 psi,so it looks like you were right on the fuel pump being bad.Thanks for your help.Mike
Yeah, thats way too low, that will give you the exact resulting problem you have with that pressure result. Its just enough to run the engine, but can't give enough pressure for engine load requirement. After a fuel pump replacement, you should be in great shape. .........Pete
Add a CommentIf anything else develops for problems, just let me know.....Have a great day.
CommentIf anything else develops for problems, just let me know.....Have a great day.
Dumb comment thing. I'll do it again.
If anything else develops for problems, just let me know.....Have a great day.
Thanks again for your help.I guess i will tackle this myself,should be able to do it.I will study it online before i do it.Have a mechanic friend who may help me,says he doesnt like to do these things anymore.Says he is getting to old.lol told him to tell me what to do and i will do it.I dont think it will be that hard.Any good pointers?Will let you know how it goes.Thanks and have a great day.Mike
drain the tanks first, it helps greatly. Take out the schrader valve (inside the testing port) and put a hose on it and put the hose into a gas can. Hook up a battery charger to your battery (so the battery don't go dead) and remove the fuel pump relay and (using a paper clip) jump terminal #30 to #87, this gives instant power to activate the fuel pump. NOTE: you do NOT need the key on to do this. Just remember to remove the jumper when the tank is empty. If you have a question on the pin location, read the relay, it has the layout on it. I'll enclose a picture. 
If the lines on the tank are really rusty you might have to get a sending unit. Look at it first before buying the pump, it will save you a trip to the parts store.
ok i understand the picture.thanks a lot for the help.:)will let you know how it goes.
the poster is correct we dont ever swap parts and assume they work, we have low fuel pressure , and do the tests, and find the REG is bad, then we REPEAT the test. DID i fix it or not>>>>>???? or the dog chases the tail endlessly.. this is called validation,. validate your work. im missed most of your posts due to running 8 them. you do your self a big dis-service to self doing that. ( like the story of looking for lost key keys where the street lamp is brighter,)
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Replace your starter.
SOURCE: 1999 chevy blazer fuel problem
probably not fuel filter . probably going to have to remove the upper intake and replace the fuel injector spider(fuel inj assebly) if it is droping fuel pressure it is leaking into the upper manifold
SOURCE: '90 3.1 lumina euro idles ok but tries to stall when accelerated.
If the cat is red then it is probably plugged if the motor can't exhale it wont run at high rpm
SOURCE: 1999 chevy silverado 4.3 new
I just replaced the fuel pressure regulator and now I am hearing a vibrating noise from the fuel line under the truck. What do you think the problem is.
SOURCE: have a 1996 corsica that i had givin to me and ive
autochoke sensor is telling engine its cold ,hence its flooding ,try changing the autochoke temperature sensor
SOURCE: 1992 Lumina Backfire - I
I know you mentioned the EGR valve has been replaced, but you may have a bad 'new' part. I know the car is electronic, but has anyone checked its ignition timing (timing belt been looked at, I know it only has 77k on it). Is the fuel pressure regulator OK and it vacumm supply?
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There is a possibility that you have an over-rich condition caused by build-up in the intake manifold which soaks fuel up and adds to the fuel causing a flooding scenario. If you want to try to fix this, I suggest that you contact a shop that has internal engine cleaning equipment and don't forget to have the throttle body cleaned also. The next suggestion is a bit trickier to solve. The fuel injectors on this model are all fired at once and the intake holds the mixture in suspension until the intake allows it to enter the combustion chamber. At high mileage, chances of one or more injectors will short out and cause the whole string of injectors to stop firing. Wierdly enough, this happens when the engine is warm. Mine failed after nearly a hundred miles of straight driving at higher speeds, but gave trouble after only a short warm-up also. The trick here is to get the engine warm and have it ready to disassemble as quickly as possible to get to the injector connections. Check each injector across it's terminals and you should see about 12.4 ohms. anything less than 12 ohms would be a good possibility of your failure. My car had some that checked way low when hot and near normal when cold. Good luck and I would appreciate some feedback. e.
Funny that you ask about the plugs,i deceided to pull them and check them today and in the process of doing that i grabbed a plug wire and got shocked.The wire was almost cut all the way through.So i replaced the wires and cts and so far car is running and restarting great.So i may have found the problem on accident.I sure hope so.Again thanks for all your help on this.I will let you know how it does.Not too many people would be as helpful as you have been.I would like to meet you some day and shake your hand.what state are you in?Have a good day sir.
shock to me (no pun) you didnt change out wires sets on 91 car? really? its in the 60k list for all cars like that, in fact put in NGK blue wires, mag wires, and they will last a very long time. I promise, wink?
ah is this not a 3.1 MPI>???? i looked it up. its not TBI.
on a real forum we'd have signatures, and Your garage and could see what you have, but not on fixya, its zero input. here.
turns out problem was bad fuel injectors and oil pressure switch,switch causes fuel pump to shut off.
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