92camaroJoe

Hello I need help

this was friday.....
So I've got a problem. 1992 camaro 5.0l tbi.
No throttle response. Barely goes. Does act like it's starving for gas. But never stalls or dies outright. Starred this last Wednesday within 30 min undrivable. Parked at idle, if u hit the throttle by hand it makes that starving for gas sound.
Replaced fuel filter, map sensor, Tps switch, fuel regulator.
As most people know it's hard to hook up for a fuel pressure test to these tbi units. So I haven't checked the pressure but there is fuel flow and typically fuel pumps just quit. This one is pumping.
I'm at a loss. And I guess in denial that it is the fuel pump.


Today....
i bought the fuel pump yesterday and was all prepared to tear it apart. I had to try and drive it to move it to where I wanted to work it about 100 ft away. it didn't make it, now it wont even start.problem has gotten progressively worse. I had hoped the pump had quit completely. It hadn't. The fuel is still spraying out of TBI. So I got a thought to get some starting fluid to see if it would then fire up. Even a car with NO gas will fire then. this one NOPE.

Im starting to think my instincts were right and its not the pump. I put a spark tester on it and its really light and it does have an aftermarket coil on it, maybe it took a crap? but even that coil has been running for 2-3 months.



Any suggestions??????????????????????

92camaroJoe

BTW i need to update my profile, my original camaro was a v-6 i have since bought this v8

Grant2k

This sounds a lot like what I am experiencing. I still see fuel spraying out of the injectors, but it's not a nice fan spray like it should be. I unhooked the fuel line under the hood near the left fender and fuel sprays out of the line when I crank it. I bought an adapter and hooked up a fuel pressure gauge and got nothing. Not even enough pressure to register on the gauge. Sounds like the pump hasn't totally died, but isn't working well enough to run the car. I'll be dropping my tank in the next couple days.

92camaroJoe

Yeah but with the starter fluid being sprayed in. IT SHOULD START THEN.

?????

antares57

iTrader: (8)

Pull your ICM, ignition control module, out of the distributor and have it tested at auto parts store. No or weak spark this may be the problem. Rule it out. Good luck.

92camaroJoe

yeah since then tried a new coil. NOPE

then pulled cap and found oil in distributor, not alot, but a light coating over everything and enough to make a drop or two pool inside cap when turned upside down.

so now i'll be spraying out the cap and trying it all again. and if that takes care of then replace the distributor at some point along with the motor.

Ill update my progress.

92camaroJoe

yeah since then tried a new coil. NOPE

then pulled cap and found oil in distributor, not alot, but a light coating over everything and enough to make a drop or two pool inside cap when turned upside down.

so now i'll be spraying out the cap and trying it all again. and if that takes care of then replace the distributor at some point along with the motor.

Ill update my progress.

Schurkey

Why would you think that? Plenty of examples of electric fuel pumps that get weak and can't manage proper pressure or volume. Or in-tank hoses that begin to leak, causing pressure and volume problems.


What do you mean by "really light"???

There's a lot of defective aftermarket ignition coils out there, and from the "big names" as well--since even the "big names" are sourcing their ignition coils from Communist China. (JUNK!)

Does the gauge you're using actually depress the Schrader valve on the adapter you're using? Not all gauges work with all TBI adapters.

You think the parts-store kid can properly test an ignition module? You have more faith in them than I do.

I'd clean-up the mess, get it running, then start looking for a defective PCV system, or a plain ol' worn-out engine. It's unlikely that the distributor is at fault for the oil residue in the cap--although it's simple enough to check for worn-out bushings. I'd expect a pressurized crankcase either because the PCV system is defective, or because there's just too much blowby.

Grant2k

The gauge I am using came with the adapter so I am can only assume it is depressing the Schrader valve. We depressed the Schrader valve manually without the gauge connected and fuel spit out but did not spray out. Even if it had 10 pounds of pressure I'd expect the fuel to spray out of the valve with some force, not just spit. And it does run on starting fluid.

This is the tool I bought.

Didn't mean to hijack this thread, sorry.

Schurkey

You should be all set, then.

You'll need to verify that the pump is getting power (and ground), the fuel filter isn't plugged, and if those are good, the pump or the in-tank hose is faulty. Test the wiring as close to the tank as you can get. If you have access to an oscilloscope and an amperage probe, you can verify pump current draw and RPM also.

92camaroJoe

I'm not sold on it being the pump. Spraying starter fluid doesn't help it. But my fuel line adapter should be in today and allow me to put an end to whether or not it's a pressure issue.

Schurkey

Are you talking about YOUR vehicle, or the vehicle owned by Grant2K?

This is why I quote posts I'm replying to. Seems to me that YOUR vehicle has ignition problems, while Grant2Ks vehicle has fuel problems.

92camaroJoe

Good Morning Schurkey
Look at the Thread, it's my thread.

Grant2k accidentally hijacked my thread and it says that in his response "Didn't mean to hijack this thread, sorry."

Im not sold on having just ignition or Fuel problems or BOTH.

My fuel spray is for ****, In my opinion. The car was barely running. started the day last Wednesday fine, within 10 miles of my end stop it went from fine, to poor throttle response to none to barely being able to move and idle. to yesterday not even starting.
Ive replaced:
Fuel Filter
MAP Sensor
TPS Switch
rebuilt fuel pressure regulator
Ignition Coil

yesterday when it wouldn't start that's when i found the oil in the cap, cleaned the distributor and cap and rotor with solvent. It started then and was able to barley move. No throttle response. barely idles.

Starter fluid doesn't seem to help at all. Starting or running. almost like the fuel is fine and that floods it out too much.

Additionally the ignition module is less than 6 months old. Spark plugs, cap, rotor, a year.

Yes I'll replace the distributor but I don't see that as the main problem right now.

Yesterday I ordered and today I got the Schrader valve adapter for fuel pressure tester shipped in from Summit. No one had one in Atlanta except Harbor Freight which the one they had replaces the fuel filter(stupid). So today I can out rule the pressure and fuel pump, yea or nea.

that's where i am I appreciate any input. Sorry you got confused by the threads.

92camaroJoe

Ok the answer we've all been waiting for.

Fuel pressure at 11PSI and holding even under throttle. That's within SPEC.

The car barely gets over 2000rpm.

Wife'sCar

iTrader: (1)

Now you know pump is pumping fine, need to figure out if regulator is good.

92camaroJoe

Hello Wife'sCar

Nobody reads any thing


Ive replaced:
Fuel Filter
MAP Sensor
TPS Switch
rebuilt fuel pressure regulator
Ignition Coil

Grant2k

It's too bad that there isn't a way to measure the pressure between the regulator and the injectors as this seems like it would be just as important as the pressure from the pump. Even though you rebuilt the regulator there could be a problem with the diaphragm or the spring and you'd really only be able to know through trial and error or throwing parts at it. That is something I was questioning until I found no pressure from the pump. In your case it seems unlikely but still something I question.

92camaroJoe

Well I'm running out of parts to throw at it.

Schurkey

I understand that you started this thread.

I understand that Grant2K tagged-along on your thread.

Anything is possible. A plugged catalytic converter or crushed exhaust pipe could cause engine running problems, as would burnt valves or pistons with holes in them.

When my 03 Trailblazer did that, the converter was plugged from me ignoring the SES light on the dash--I was 3700 miles into a 4000 mile trip, and had no tools with me. Spent two days in the middle of nowhere waiting for a replacement converter to get welded-in by the only repair shop in 30 miles.

Never mind how long it's been since the spark plugs were installed. What are the chances that they're fouled from the various other problems the car has had, and now they're what's preventing proper operation?

You've added fuel, and it isn't helping. This makes it somewhat unlikely that the fuel system is at fault.

The TBI-style small-cap HEI has a common problem with the pickup coil. The magnets break, causing weak signal to the ignition module. This results in misfire, and eventually stalling and failure to re-start. My own K1500 had this problem years ago. The fact that you have oil in the distributor cap area is probably not the fault of the distributor, it's likely too much pressure in the crankcase from a faulty PCV system or excess blowby, as I said in a previous post.

Again, check spark plugs for fouling.

How can the regulator NOT be good if the pressure is OK? The only way I can think of is that the pump is weak (cannot put out more than 11 psi) and the regulator isn't actually returning any fuel because the pump can't overpower the regulator spring--which still wouldn't be a regulator defect, it would be unusual regulator operation in response to a pump defect.

The functional result is that the pump would probably be short on volume, so while pressure is marginally correct at low-demand, the volume would be very reduced. This would lead to a loss in fuel pressure as the demand increased--higher RPM or higher load.

Since 92camarojoe says the pressure is acceptable even with increased throttle, this scenario doesn't seem likely.

Again, unless there's a faulty pump in this equation, the diaphragm and spring would be fine. There is some remote possibility that there's a restriction between regulator and injectors (plugged injector screens???) The problem here is that adding additional fuel doesn't help the vehicle run better. FUEL SYSTEM IS NOT MY FIRST THOUGHT. I THINK THIS IS IGNITION-RELATED.

SO: 92CAMAROJOE:

If this car was in MY driveway, I'd yank the plugs for inspection. I'd probably end up cleaning them via grit-blasting or--at minimum--"burning them clean" with a propane torch. The propane torch won't get hot enough to damage the plugs, but it does a nice job of removing oil and, especially, gasoline from the porcelain.

I would perform a compression test to verify valve and ring sealing. Given that you probably have excess blow-by, I'd be looking for oil on the plugs, and I'd probably perform a cylinder leakdown test to double-check valve sealing, and to quantify leakage past the rings. It would be nice to verify that the spark plug wires and (secondary) coil wire have acceptable resistance, and no insulation tears/cracks/burns. I've seen TBI coil wires with excessive resistance that lead to massive misfire. Speaking of this,
You never did answer this.

What kind of "spark tester" are you using?

If the compression test was acceptable, and with cleaned (or new) spark plugs, I'd re-try starting the engine and see what happens. If it doesn't fire up, I'd pull the O2 sensor (to provide an exhaust outlet) and try again. If it runs with the O2 sensor out, you've got a plugged exhaust.

92camaroJoe

Hey Schurkey

Yeah I thought about the converter. the exhaust feels like its flowing out the tips but you still never know.

My last thoughts are:
I bought a new distributor that includes a New cap, rotor and module. Maybe the module got ruined by the oil somehow? I know they're sealed but I've seen fluids get into sealed electronics before.

Yeah, then my next thought was to take the pipe loose at the head of the converter.

if not then, remove and check plugs even though they're less than 2yrs old and low miles. Then Check compression.

After that. I'm all out of ideas. besides going back and changing the pump despite the spec range of the fuel.

change the spark plug wires again?
I don't know?

92camaroJoe

OK New distributor with new cap and rotor and module installed.

Seemed to help, just a little, starts very quickly now but still stalling out.

But to repeat its not like an ignition cutout, its like its starving for gas but it's not. Maybe it is the exhaust. I'll unbolt the pipe in the morning.

to recap trying to fix this problem:
New:
filter
distributor
MAP Sensor
TPS Switch
another New Ignition Coil
Cap & Rotor
Ignition Module
rebuilt Fuel regulator & TBI assembly
Fuel Pressure Checked 11PSI and stable

within last two years new plugs,wires, cap, rotor, module, ignition coil, alternator, yellowtop battery, waterpump, heatercore, radiator, coolant switch for fan, upper radiator hose, heater control valve
New compressor, dryer bottle, accumulator, converted to 134a
Hypertech chip
NEW exhaust from back of catalytic converter
Airpump delete smog pulley

Been a daily driver for 2 years

92camaroJoe

At last PRoblem fixed
CATALYTIC CONVERTER, was all plugged up. driving me crazy for days!!!!!!!!!!!!!!!!!!!!!!!. And all that back pressure probably pushed the oil up in to the distributor too.

92camaroJoe

thanks everyone for your input

Wife'sCar

iTrader: (1)

As a matter of fact I do read, just because you rebuilt it does not mean that it's A OK 100%, new parts can be bad, yay you fixed your issue but you came here for help, which is all I was trying to do. So good luck with anything else you run across and have a nice life.

92camaroJoe

No you don't read your reply is a simple **** you. Your quote simply read is.

1) I didn't read it. Or



QUOTE=Wife'sCar;5951720]As a matter of fact I do read, just because you rebuilt it does not mean that it's A OK 100%, new parts can be bad, yay you fixed your issue but you came here for help, which is all I was trying to do. So good luck with anything else you run across and have a nice life.[/QUOTE]

92camaroJoe

No you don't read your reply is a simple **** you. Your quote simply read is.

1) I didn't read it.
2) Or, I'm giving you credit here. I read it and I'm assuming you don't know what you're doing and rebuilt doesn't mean it's 100% ok, Because you don't know what you're doing. And you have NO way of testing if new parts are bad.
Trying to help is not what u intended.


In either case, "GOOD LUCK AND HAVE A NICE LIFE" means **** off. And I extend those same goodbyes to you.



QUOTE=Wife'sCar;5951720]As a matter of fact I do read, just because you rebuilt it does not mean that it's A OK 100%, new parts can be bad, yay you fixed your issue but you came here for help, which is all I was trying to do. So good luck with anything else you run across and have a nice life.[/QUOTE]

Wife'sCar

iTrader: (1)

Here's a parting story and I'll be on my way. My car wouldn't start after new motor was put in. No spark, power going to the coil but no spark out. I replaced the coil with a brand new coil, still wasn't getting spark. Guess what, the BRAND NEW coil was also bad straight out the box. You said it was acting like it wasnt getting fuel, pump tested fine, next thing in line is the regulator, which you messed with. Next in line is the injectors. Cause and effect. This is an online forum. It's like a doctor trying to diagnose someone's disease through an online chat. We can only respond with our best guess with the info provided. You asked for help.

I did read, I left a comment based on the info you posted, and you singled me out in an attempt to make me look dumb. I didn't appreciate it. I responded in kind.

jombo23

Wow man, for someone who needed help youre sure jumping down everyones throat.

I understand you could be upset about the crap going on with your car, but good god dude, take it down a notch.

And no, the way he said it was more along the lines of

"Huh, ok bud, i was just trying to be friendly and helpful and you were a giant butthole about it"

Youre the only one whos been hostile here

Rob 689

94 GMC K1500 5.7L 4x4 198,000 miles

Mine had the same issue and it was the fuel pump. I got back from being out of town for long enough for it to go from fall to winter when I got back and the truck would run like crap sputtering and stalling and generally undriveable until being at operating temp for some time.

Then after several days of driving the truck and hunting the problem down it too died. Injectors also had **** poor spray pattern on the last couple times that it ran. After trying to start it till the battery died it even flooded so bad fuel was pouring out of a couple manifold leaks and the donate to the y pipe.

Starter fluid also had zero effect and same with a splash of gas down the throat still wouldnt start.

I hunted for the problem off and on over the course of about a month it happened over Christmas break. It was 20 below almost everyday and plenty of wind. It was fun….

anyways it ended up being the fuel pump. Only had 9 and 1/2 psi while cranking

new pump runs about 15/16 psi

service spec is 12-15 psi

i also cleaned the pumps ground on top of the frame rail near the tank and coated it with dialectic grease. (After installing the new pump pressure was still a little low and I found I was losing a couple volts to the ground when I did a voltage drop test with a multi meter on the new pump. Repairing the ground brought it up about 3 psi

The reason the fuel or ether won’t work has to do with the proper air to fuel ratio. The cylinders don’t “burn” the fuel it “combusts”. Combustion requires the air to fuel ratio to fall within a very specific range. Every fuel type also has its own stoichiometric air to fuel ratio.

If the intake charge isn’t stoichio metric it won’t combust and fire the engine.

Mine also had and still has seemingly weak looking spark but runs perfectly fine. It also has an aftermarket coil, Scott or something like that I thing was the brand name.

truck runs flawlessly now…

Schurkey

Do you speak well of this dialect?

The air-fuel ratio does not need to be stoichiometric to burn (or combust...same thing.)

Stoich is approximately 14.7:1 although as you noted, it can vary depending on the chemical composition of the fuel.

Starting an engine--especially a cold engine--requires a much-richer-than-Stoich mixture as delivered by the fuel system. Only vaporized fuel burns well; the fuel delivery has to be extra-rich because some of the delivered fuel doesn't vaporize in the cold. This is why carburetors had chokes, and why fuel injection systems spray an extra-rich mixture when the temp sensor shows low temperature.

Similarly, best fuel economy (but NOT best emissions performance) is with leaner-than-Stoich fuel mix. GM provides "Highway Lean Cruise"; a fuel-injection protocol that drives the fuel mix leaner than Stoich--but only for vehicles delivered to countries that don't regulate NOx emissions. Substantial improvement in fuel economy, substantial increase in NOx emissions.

Gasoline-fueled engines will run with fuel-air mixtures from about 10 or 11 to one, down to fuel-air mixtures of perhaps 16 to one. A fairly wide range compared to Stoich. They run WELL from approximately 12.5 (Power) to 15--15.5 (Economy).

Buccaneer

You guys do realize this thread is six+ years old...I'm sure he has it fixed or maybe junked by now.

jwwiggins57

I've read through all of these replies and haven't seen any reference to the infamous new style distributor caps. If your distributor cap has the plug wires pointing out the cap sideways I can almost guarantee that it will be a bad distributor cap. I have had a motor run fine then shut it off and restart it and barely run - limp it home and wouldn't restart again. It was so bizarre I replaced the spider assembly on the EFI and more.
A guy told me to get a new cap and I ignored him -for a few days, bought a new cap and it roared to life. Same problem on the 305 V6, any cap with the wires pointing sideways will start crossing where the conductors cross each other in this terrible design.
I have since seen this problem repeated on four engines

antares57

iTrader: (8)

See number 5.response. A bad icm will allow the car to start but as soon as it heats up it will die.