Hello everyone. Been a while since I have been on here. Actually we're talking years. So now that the foreplay is over time for business.

97 Sunfire 2.4 5spd, ~95k on car ~60k on motor.
I stopped driving the car due to a idle problem. It started with it on occasionally not starting and then it would just sputter. Well took it to the shop and the guy replaced the coils and still had problems. But could drive it. Then what would happen is i would drive it and it would run, but when you would give it gas it would sputter or bog, but then would get past that. Wouldnt matter what speed. Could be cruising at 40 and then give it gas and it would bog and then go.

Well now it wont start at all. It will sit for a few days or weeks, then i go in and turn the key and i turns, and i get a little sputter, but will not run, and then after that will only turn. No combustion.

So what do yall think that could be. Before i took it to the shop before I put in a new fuel pump and was having the same problem with it, and then put the old back in and it worked, so that made me think the pump was ok, but now i have no idea. Its got a new fuel filter on it, and my F/P-inj fues is good, and i tested the relay, but I am at a loss. I have a used ECU out of a auto, was thinking about trying that out. I get no codes, so that doesnt help. Not sure if the auto ecu would work or not.

dont use the auto. ecu....thats a dumb idea.


here is the step by step of what you need to do:


1) are you SURE its getting fuel? just unplug one of the injectors, have someone crank the key and see if fuel is being sprayed. if it is, disregard the fuel system.

2) next, are you SURE its getting spark? once again, unplug one of the spark plugs, make sure you ground it to somthing when you try to crank the key, and see if it sparks.

3) if it is getting both spark and fuel, then you need to move on to compression. you need to have someone (or you can do it if you have the tool) do a compression test on all the cylinders. it could possibly be that one of the cylinders is under-compression, which can cause this kind of trouble.

4) if all the compression in the cylinders is good, move on to the cam position sensor, and that could be why is sparking and spraying fuel at the wrong time, but this will usually give a code, so it might not be this, but its easy to check.

do these things in the order i posted them, then make a new post and let me know what you find out, and weather it worked or not.

hope this helps!



- Cameron (CaliforniaCavalier)
- www.csc-motorsports.com (my new NOR-CAL car tuning site)

Ahhhh thanks for the reply. Yeah i have had that auto ecu in the garage for about a year. Was never sure on that, got it on ebay and then realized what i did.

Actually your first step is exactly what I was wondering about being able to do. Glad you mentioned it. I wasnt sure if you could test it that way, but it seemed to make the most sense to me, if fuel is getting there, then I can rule out fuel delivery, or at least to that point.

I'll definately do that and let you know.

Well, that turned out kind of like I expected. But more work though. I can never find the right tools at the right time.
So anyways I removed the fuel rail with the injectors, and had my gf turn it on and over and nothing happened. All fues are good, so gonna chase the circuitry back to the tank, starting at the relay, then the tank pig tails.

If you have any other suggestions let me know.

when it dont, start, try flooring it. i know it sounds stupid being it is a fuel injected car, but on my other car that is fuel injected that worked somehow. worth a try, lol.


when he replaced the coil packs, did he do the housing too(that is the big white thing). that can have carbon tracking on it and mess things up.

things i would do if i owned your car. do the new white coil pack housing, plug boots and new ac delco spark plugs.

if that dont work, fuel filter.

if that dont work, cam or crank sensor. (helps to have a pull ur own part junkyard near so u can grab these sensors realtively cheap).

if that dont work, tps sensor.
check all vaccum lines, mainly the one going to the map sensor, maybe that is cracked.

or your Fuel pressure regulator could be bad.

if that isnt it, bad ecu.
if it aint something i listed, off to a GM shop it goes, not the first guy who worked on it.

sucks u arnt getting any codes. or maybe ur are? go to autozone and have them scan your car for free and see what it says. i seen cavs have a code, but no light. these cars get weird.

good luck

I'd like to bring it over to AutoZone or Advanced. I have done it before for my truck. But the car wont run so i cant get it there. I'd bring it to the dealer, but dont wanna pay the additional to get it towed, but may have too.

Hey, is there anything else other than the obvious (wiring, pump, filter, fueses) that would cause the fuel system not to run. For example is there a sensor that would act like a fuel cut off. It seems i read something about that before (crank sensor)? And then the ecu, b/c there was nothing coming out of that rail when i tried to turn it over, and would like to make sure before I keep testing and it gets to a point where I have to drop the tank again to try another $200 fuel pump.

Thanks

Well guys I have made alot of progress with this. And thanks for all your help. Not fixed yet, but is getting there.

Here is what I have done:

I removed the fuel rail and the injectors and tried to see if there was anything coming out. Nope not a thing.

I checked the relay and even the 57 (i think) terminal to try and see if i could manually get it to pump and nothing happened.

I went under the car to go ahead and drop the tank to try and take out the pump and try and wire the pump directly to the battery, but lucky me my gf had other ideas.

So later I went out and decided to run a wire from the pos term to the pos wire going to the pump. If anyone wants to know its the solid grey one. Not the grey black on. But that was halted when a huge @#$%ing wolf spider was right there. Shoved him off, and then proceded, but nothing happened. Not sure If was not grounded right or not.

Next pulled out the back seat and found the wires going to the tank. Stripped a little back from the grey wire, and with the wire connected to the battery, i touched them and whrrrrrrrr. My pump was a pumpin. In fact I pump most of my gas out into a gas can this way.

So now I know my pump works. But why not when its supposed to.

Next i tried hooking wire from battery to the FP/INJ fuse on both connectors and nothing. I dug up the wires to the fuse panel and stripped a little off and touch my battery wire to it and it worked.

I then ran my long jumper wire from the pump wire, and touched it to both parts of where the fuse connects and nothing happens. Which kind confuses me. I am not sure if the problem is coming to the fuse box from the relay in the engine compartment. Or if its a problem with the connections for the internal fuse panel. Either way, its gonna be a bitch if i have to replace some wire.

So this is where I am at now. Tomorrow I am gonna remove my fuse pannel, and take a peek. Definately gonna need to buy a test light.

Any possibility that my PCM could be causing this? I really hope not.

[quote=Firestorm2|4 v2.0]Any possibility that my PCM could be causing this? I really hope not.

i highly doubt it. the PCM for the most part monitors all the on-board sensors and makes sure they are all working properly. the PCM sends the info back to the ECU, and if a sensor isnt working properly usually you will get a CEL.

so the fact you arent getting a CEL, leads me to believe it isnt the PCM. but later down the road if you dont find the problem, take the car to a dealership and have them test the PCM. it will cost about 100$.

hope this helps




- Cameron (CaliforniaCavalier)
- www.csc-motorsports.com (my new NOR-CAL car tuning site)

Sounds like the fuel pump relay is stuck / not switching or not getting power.
Don

The relay itself is fine. I swapped it out with the A/C relay, which is the same type and nothing happens. But the problem could very well be there. I am going to get a test light for sure to see today.

Ok time for an update. After i determined the fuel pump to be working, or at least it seems, i started to chase the electrical. I removed the dash, and fuse pannel. The wires up to the fuses inside were fine, I noticed I wasnt getting power to some connections at the pannel, and it looked like the plastic around one of the leads looks a little distorted. There was no power coming from the big pig tail.
So from there I started looking at the wires under the hood. I opened up the engine compartment fuel assembly and removed the wire loom from the big harness to the connector that goes to the inside. They looked good, i saw one that was bare wire, but it was not related to that circuit, may some discolloration on one of the f/p wires, but it was hard to tell since they use different shades or red/pink. So i went back in the car to put key on, so i could try to test for current with my light and there it was, the pump was a whirring. Turned off and on and could still hear the pump. I even pumped about 2 gallons out to my gas can from my fuel line, just by holding a lead from battery to the F/P power wire.
Now this is where I am. The dang thing works and i havent actually fixed anything. I put everything back together. New O-rings for the injectors and fired her up after jumping the battery. It ran for 30 min and then i took it for a drive. Well it drove fine. No hessitation, good 2.4L acceleration. I took it to Advanced auto parts, to get engine codes pulled, and will show those later and in another thread. But on the way back, i noticed a little hessitation on acceleration. Not as bad as before but definately similar.
I am just not sure what to think of this. I am considering ordering a whole new harness from a salvage yard and replacing the main one.

Ahh wait, there is more. I almost forgot. For some reason now, my guages will not light up. The needles do, but not the face. I also had a illuminated overlay and when i connect it as i did in the past to one of the fueses, it will not turn off. With the headlights off and the key off the circuits are still hot. So i have to remove the wire. It seems that there is current running through many of the fuses. I had the wire for the overlay wrapped around the fuse for the cluster, and in the past when i would turn on/off lights the overlay would turn off. Now it will only stay on. And also, the fuse for the inst/cluster (i thing, the red one below the F/P-inj fuse, when you remove it and connect it, my ABS chunk under the hood, starts clicking like crazy. Not sure how they are related, other than the guage idiot light.

Ok bored now. Let me know if you have any suggesions.

The codes i got from adv are: DTC codes: P0107, P0405. DTC pending codes: P0121, P0405