1990 chevy lumina

[tblake]

thanks a lot, that settles it then, I'm gonna get one of those scanner things. and as a matter of fact, i did have it in to country chev about 7 miles away from where i live, and the service tech got in the car, drove it and said, it didn't stall for him at all, so I got in with him, and it didnt stall then either, maybe tempermental? go figure. At any rate, I get more and more of a delay when I hit the gas and the car finally goes, could this be the ignition compression sensor? thanks a million guys, your big help.

[noodle32]

I had that same exact problem - sounds like your either your fuel accumulator or your fuel pump is going - more your accumulator than your pump - engine doesn't sound like it's getting the pressure that it needs and that's the job of that car part - like when you press on the gas it feels like the engine is almost trying to exhaust itself backwards until it finally goes right - improper air/fuel ratio - I would seriously have that fuel system checked out if thats whats causing it Hope this helps!

[tblake]

ya, thats kind of what I was thinking. bad fuel to air ratio. A friend looked at it, and said something about the throttle position set screw? He said, its not letting ait in right away, and it gets gas, so it kind of floods, and then once the throttle is pushed far enough, air comes in, and it goes. maybe this is true, i don't really know. He seems like he knows what he's talking about. maybe i should look into that too, huh?

[tblake]

by the way, where exactally is the fuel accumilator? Is it in the gas tank like the fuel pump is? This weekend I am also going to change the fuel filter myself so i know its done right, I had someone else do it last time, and to make a long story short, that was last summer when I was having a shit load of trouble with the car, and I took it to this fast lube in my town, and they drove it into the shop to change the fuel filter, and to get it out, the guy said, they "Put gas in the carburator". I looked at him like, and i trust you to change a fuel filter on my car when you think a fuel injected car has a carburator? anywyas, I dont go there anymore. So I was thinking this dumbass might have fucked something up, because when I think about it, that is when all these delay problems started. Also i dont know if they put a good fuel filter in it or a crappy kind, you guys know of any good ones? Thanks.

[noodle32]

Definately I would check into that - also you might want to have your air pressure regulator or your fuel pressure regulator as well

[tblake]

I got the gm code reader which is a pretty nice gadget. It tells me error code 45, which means rich exhaust. I dont know, maybe getting too much gas? Also it said to pull the fuse for the ecm for 15 secs, and run the car for 4o miles and test it again to get new ecm error codes. Which i might do. Any ideas on the rich exhaust? Thanks

[noodle32]

Just as I thought - you have a bad air/fuel ratio - rich is actually bad - means you're getting too much fuel and not enough gas - lean means that you're getting too much gas and not enough fuel - I have made a list of components that are usually found in just about every vehicle that should be checked in order to find a proper solution:


Air Temperature sensor<-one of my guesses
Air flow sensor<-one of my guesses
Mixture screw<-one of my guesses
cold start injector<-one of my guesses
auxilary air regulator<-one of my guesses
Oxygen sensor<-one of my guesses
Fuel pressure regulator<-one of my guesses
Fuel accumulator<-one of my guesses
Ignition
Relay
throttle valve
Idle screw
throttle switch
RPM signal
Thermo-time switch
Engine temperature sensor
Fuel injector
Fuel Rail
Fuel Filter
Fuel pump
Fuel tank
ECM/ECU
I would also consider getting an air/fuel ratio meter - they really work wonders cause this problem can lead to costly repairs if ignored over time Hope this helps! I would also try that 40 mile thing - what that'll do is reset the ECU to break the electronic cycle and possibly realize what it is doing wrong and correct itself

[tblake]

ok, thanks a lot. A buddy of mine told me that some cars have 2 O2 sensors, one before the catalyic and one after, and he said if they both get the same readings, then it will trip the service engine soon light. Is this true, and does mine have 2? I found one before the catalyic, but I didnt look after. Also I was planning on trying that 40 mile thing. I just hope it doesnt leave me stranded. Is it possible that this will solve my problem? Also I did take if for a short 85mph trip for about a mile late last night down the freeway, so shhh. And this seemed to restore a lot of take off, but it still does its delay thing. I am gonna go a lot farther when I have more time. Last night I just didn't. Thanks for all your help already, and I'm gonna look in those things you listed.

[noodle32]

There should only be one catalytic converter per manifold on the engine - unless they're plumbed together of course - so if you have two separate mufflers on each side of the back of the car then you may but if you only have one then you only have one cat and therefore you only have one O2 sensor but the air fuel ratio is usually calculated by the O2 sensor which is connected to your cat - I would definately have your fuel accumulator (stores the pressure needed to start up the car in even the coldest weather) and pump (to make sure that enough fuel is normally being pumped into the distributor and ultimately the injectors) checked out though - the accumulator holds the pressure needed to ensure proper start up (also check to fuel pressure regulator as well to make sure not too much is being sent to the distributor) and the pump is self explained - if any of these need to be replaced - improper air/fuel flow will occur to the engine I would watch that speed though just to be on the safe side - too much pressure to the engine may actually do more bad than good for both your fuel system as well as your engine If you have no problem starting up though - it wouldn't be your fuel pump and accumulator - but more your fuel pressure regulator or something else listed - or it could just be a bad O2 sensor - they do go bad so I would check that out as well Hope this helps!

[The Burning Rom]

Your car has 1 oxygen sensor in the rear manifold. It DOES NOT have a second sensor after the cat. That is only on ODBII cars. It also ONLY has 1 cat...regardless of how many mufflers it has. No w-body was ever sold with 2 converters. I would start by replacing your oxygen sensor, cleaning (or replacing) your throttle position sensor, and doing an idle re-learn procedure that can be found at www.60degreev6.com

If that does not cure it, then I would look into other sensors as causes of your problem.

If you still think it's fuel related, get a fuel pressure gauge and connect it to the test port on the end of the fuel rail (should have a black or silver cap on it) and see what your fuel pressure is at.

[tblake]

in reply to noodle32, My lumina has no problem starting at anytime, cold hot, rain, no problems. And when I do start it i can hear the fuel pump running for about 5 secs and then it shuts off, and I turn the key to start, and it starts right up. So if this is any help to you. I am going to look at it some night here though when it isnt so cold out. I live in minnesota, and lately it has been very cold. I'll keep you informed, Thanks a lot.

[noodle32]

Just glad I can help It's the worst thing having to start a car and have it have problems - esp. when the fuel system gives ya grief - cause it seems simple but its stages make it so complex and difficult to understand - just glad I could shed some light on the subject My friend had an 88 Camaro and he loved that thing - but when that fuel pump went - you'd swear he lost a family member while it was being replaced - cranked forever but wouldn't turn - I had the same prob but it was the cold start - course I had to replace most of my 13 year old parts anyways figure if you're gonna go replace one thing in the system - may as well replace the majority to ensure it's reliability even more - cause nobody likes to be stuck esp. in the dead of winter

[tblake]

Thanks a lot guys, I did that idle relearn, and she sure idles perfect now, but it still has problems delaying. I have noticed that if i get in it and its 100% cold, it doesn't delay at all, but when its hot, not hot hot, but normal hot, it delays. I was also going to ask you where that fuel accumulator is located. Is it on the fuel pump. If it is, my fuel pump is in my gas tank, and a way too big job for me. Also I was wondering if a Hays repair manual would tell we where all these sensors are, because I am used to working on carburators, not computer controlled fuel injected. Finding the right sensor to me is like finding a needle in a hay stack. Thanks a lot.

[tblake]

New problem about my 1990 Chevy lumina. Its been getting cold here where i live, and I notice that when I start my car in the morning, it starts perfect every time, but I need to leave it idle for about 20 mins so it doesn't miss while I'm driving. It misses all the time till its warm. I can also feel it miss. The car shakes while going down the road, and acceleration is very very bad. I cant get it to even go 40 mph if i start it right up, and drive it right away. Plugs are new, and plug wires are too. Also is the coil. There is no distributer on this car being that its a 2.5 4 Cyl. I have also had a delay problem as I posted here earlier. Also I have bought a code reader from wall mart for 20 bux, and I plugged it in, and found out that I am getting rich exhaust. Which is triggering the "Check Engine Soon" light almost every time i drive it. The light comes on and a few secs later shuts off. i would like to know how to lean out my fuel to air ratio. Could my missing problem be a faulty plug wire, or a bad plug? I would like to put those 4 prong plugs in my car to increase horsepower. Do they actually increase horse power, or not? Also at my earlier post I have said that my lumina stalls. It doesnt anymore, but it still does delay pretty bad though. Any ideas about whats wrong would be greatly appreciated. Thanks a lot.

[noodle32]

According to howstuffworks.com - I guessed that you were having a bad air/fuel ratio problem - when your engine is running too rich it means that theres too much fuel being burned and not enough oxygen - the reason for this is usually because the oxygen sensor may need to be replaced - the function of this sensor is to calculate the air/fuel ratio to the ECU to give your car the best performance based on all the other multiple calculations that it is recieving as well - when the Oxygen sensor goes bad - the ECU begins 'guessing' the air/fuel ratio - which is very bad for the performance of your car - it could run lean one day and rich the next in some of the worst cases - this would definately be a good place to start - here is also a site where you can get one at a reasonable price ($40) - hope this helps!

http://www.autopartsworld.com/new/pr...umina&x=93&y=5

Source of HowStuffWorks Air/fuel ratio site:

http://auto.howstuffworks.com/question257.htm