94 cav died on the hwy. Won't start now!

[hunt101447]

I have a 94 Cavalier 2.2L Automatic with 154K on it. Bought it used in 95 with 27K on it. This car has been running great for me until the other day. Driving down the highway a couple of days ago it started losing power to the point that I pulled it off the road, where it promptly died. When I tried starting it, it would turn over, but would not usually start. Occasionally when it did start it ran extremely rough for a few seconds and then would die accompanied by a cough coming from the throttle body. Had it towed to my house and started working on it.

The check engine light is not lit. Still, I went out and bought that GM code checker. I didn’t get ANY codes, the Code 12 didn’t even flash. When I looked in the book that came with the tester, it said that certain cars could not be tested and the 94 Cavalier was on that list. Is this true, or should I be swapping out the ECM? The Check engine light does come on when I turn the key to on, so I know the bulb isn’t blown.

Checked all the fluids. ¼ tank of gas, oil and water were good (oil was ½ qt low), tranny fluid is fine too. All the spark plugs are in good condition (light tan, no black stuff or damage). Checked all 4 plug wires for spark and that was good too (got zapped while testing one of the wires-my fault)

My friend said it sounded like the timing chain had skipped a tooth which would explain the extremely rough running and the cough, so we decided to check the timing chain and see if the marks line up. If you’ve ever thought about doing something like this, lock yourself in the trunk until the thought goes away. Use a hammer if necessary. You have to move quite a few things. For starters.. the alternator, power steering pump, belt tensioner (these 3 block the top portion of the timing chain cover). Next comes the oil pan, starter, and exhaust pipe. (In order to drop the oil pan you have to move the starter, and to move the starter, the exhaust pipe has to be moved….all this just to get the timing chain cover off. The chain was in great shape and the marks lined up. Everything was put back together with new gaskets/seals. The one good thing so far is that the oil pan now has a new gasket so hopefully I got rid of that annoying leak the car has had for years. The bad thing is that there has been no change in symptoms.

Also did the following:
Swapped out the crankshaft position sensor.
Checked for vacuum leaks (didn't find any)
Did a compression check and the pressure in the cylinders ranged between 160 and 135 PSI. The manual said there should be a minimum of 100 PSI.

I’m at my wits end with this problem. Should I buy the ECM for this car since the codes didn’t flash or can I take the work of what the GM codereader book said about it. What else should I try?

Thank you for any responses.
Tim

[jayson716]

what about the battery? some times when the battery looses the charge and doesnt charge fully it wont have enough power to start the car.other than that i would say the injectors got clogged or are going bad.

[Mangoamerican]

Im agreeing with jayson, check your injectors, maybe your fuel pump too.. it could be bad gas! or maybe your fuel pressure regulator.

[hunt101447]

I forgot to mention that in my post last night (was up until the wee hours of the morning working on the car). The car doesn't have a normal fuel injection system. It has that Bottom Feed Port Injection (that's what the Chiltons manual calls it anyways). There's only one fuel injector in this car. I figured that when the car would start up and run roughly, then the fuel injector was working and something else must be wrong with it. I'll pull the injector out and take a look at it today. I took the battery and alternator up to the auto parts store and had them tested. They were also good. I have drained the battery, but a few minutes jumpered to my neighbors car and it charged right up. I'm getting ready to head to the parts store and pick up some new plugs and wires.

[hunt101447]

Scratch the plugs and wires part of my post. I'm going to check the fuel system stuff next.

[hunt101447]

Ok, brain damage on my part again. It does have 4 fuel injectors. I pulled off the fuel filter. I had a rag wrapped around it as I did it to keep from getting sprayed. I could tell that there was pressure in the line because of the way the gas sprayed out of the connection when I took it off. I can blow through the filter, so it's not clogged. I'm going to pull the injectors next.

[public]

This car has a OBDII computer with a OBDI plug. Only a few code scanners will work with this car(I have one too). So no code is the usual.
You may still need to check or replace the plug wires $13. Although is does sound like it is fuel related. Be sure to check or change the oil sending unit, this car will shut off the fuel if the oil pressure gets low. The sending unit is near the module on the back of the motor. Cost $6 or so at autozone.

The next time you want to check the timming chain, remove the passenger side front wheel, remove the inter panel and there is the cover. Just remove the pulley and you are there, takes about 30 minutes.

Also check you air filter box. I spent a lot of money once after a plastic bag got sucked in. It did basically the same thing as you describe. I felt pretty silly when I found it. Good Luck.

[hunt101447]

Swapped out the plugs and wires. Still no change. Decided not to pull the injectors yet because I doubt that I had a catastrophic failure of all 4 injectors at once.

Thanks for the info on the OBDII/OBDI computer issue. Is there any way to make the codes show up without the scanner?

I've lifted the cover off the air filter so that the car can suck air that way. That had no effect either.

I'll also check the oil sending unit tomorrow. I'm glad to hear it's only 6 bucks. That camshaft position sensor I bought cost a bundle.

[princeal]

Have you checked fuel pressure I had a fuel pump go bad but still created pressure in the line but not enough to activate the regulator Just a thought and good luck

[hunt101447]

I had to work late tonight so didn't get to the parts store to pick up a different oil pressure switch so instead I jumpered the pins on the plug for the switch. I've been in the Navy for 17 years, so far, as an Electronics Tech, so I was able to figure out the wiring diagrams. Again, no luck. I have noticed that the fuel smell from the throttle body had greatly decreased since starting this adventure, even though I can hear the whine from the fuel pump. So maybe the pump was on it's last legs and was just fooling me until now. The next step will be checking out the pump. (I know, I know, that's exactly what you guys said in the first place.) I'll let you know how it goes.

[BlazerLT]

Plugged fuel filter

Plugged Cat Converter

Fuel Pump Wearing out

Stop throwing random shit at the car looking for a miracle.

Check for spark, fuel and air intake before you start timing the vehicle and swapping out sensor needlessly.

Have you even check fuel pressure yet?

[hunt101447]

It hasn't been random shit. Plugged Fuel Filter...I said I could blow through the filter. Ditto spark (got zapped once), air intake (lifted the cover off the air filter), fuel pump (got sprayed). I did assume that the pump was still good due to the way the gas sprayed when I disconnected the filter. In my post prior to yours I talk about going back and checking the fuel pump pressure. And when this whole mess first started out, it did sound like a timing problem the way I'd get that extremely rough running followed by a cough/backfire through the throttle body and a strong smell of gas. I've seen plug wires go bad in a way that when the wire next to it fires, it induces a spark in the wire next to it, and these wires were a few years old. And the plugs, well, it was time to change them anyways.

[richtazz]

check fuel pressure. if it's low, pinch the return line. If it goes up, change the regulator, if it doesn't go up, replace the pump.

[4dr92cavi4cyl]

You have spark and fuel going to the rail, have you checked (test it with a test light or something) the Injector wiring harness? It may have short or rotten wire. Wouldn't that cause the ECU to show a code or not?!??!? My ¢2...

[BlazerLT]

Plugged Cat would cause this.

See if the timing jumped a tooth but don't change sensors unless you get a code from it.