So this starts two weeks ago...

The car died on me. All was fine, when I stepped on the pedal it went, then all of a suden just dropped to 1,000RPM and jumped high and low a few times before stalling.

When I got it home, it cranked, fired then died. Neighbor suggested the fuel pump. He said:
1. The pump didn't start when initially turning the key (no hum heard from around the tank).
2. If it was the ignition module, the engine would have never fired, but we would have heard the fuel pump run 2 seconds.
My father agreed with the reasoning and we got a new pump.

Now, again, it died on me tonight. Get in the car and it fired and died. It ran fine earlier in the day after installing a new fuel pump. On each attempt it would fire and pretty much die right away. Sometimes it would struggle to stay alive. Some attempts it would only crank and not fire, and those times the fuel pump was not heard.

In the rain the bright idea hits me, try the relays. Swap the FP relay with a new fan relay, and the car started. Ran like crap though. I was able to get it home, but felt like it was missing badly. Felt like my mother's Grand Am when the ignition module went and it was running on 2 cylinders.

Have I been misinformed as far as the ignition module goes? Would I not hear the fuel pump when turning the key if the module is bad? I did a search, but no mention of this condition in any posts mentioning the module.

Even cool, it will not start.

I'll be checking the usual tomorrow, but ask because I don't want to pull the module if it's not a possibilty -- I'm tired of pulling crap just for the hell of it.

 

If it held the pressure from the first prime, you won't hear it again until the pressure drops.
Have you checked for trouble codes?
The ignition module can be tested at a parts store.
My experiences with IMs is that they either work, or don't.
You might want to check the distributor connectors that may back out with vibration because of broken locking tabs . One member had a condition where everything seem good, but didn't get fire, turned out to be a bad battery ground cable, current was enough to crank, but not fire.

It's answers to problems like this one that others like to hear about, never know when it might happen to one of us.

 

Good to know. I figured trying to start it would drop pressure enough, so I should hear it every time.

First thing I did was check for trouble codes. I'm sorry I thought I had included that in my post. No codes came up.

Yeah I'm going to try to do that tomorrow, as well as...

I checked that after a , the connectors are in place. Tomorrow when its light (and hopefully not raining) I'll be checking the condition of the wires themselves.

 

Ok, some new observations:

1. On the first start after sitting for a while, it will run, no problems.

2. Shut the car off, wait 15 minutes, it will start and run, no problem.

3. Wait an hour... now it won't start. Has spark. Same as before. Took a timing light, EST lead disconnected, and its all over the place. Each flash of the light gives a different reading.

4. Wait two hours, back to 1. Starts and runs, no problem.

Haven't really taken it out for a drive because I don't want to get stuck again and be harassed by GEICO for being towed so much. SO basically by "runs fine" I mean no problems driving around in the driveway for 10-20 feet back and forth a few times.

 

Still nothing.

I took ideas from searches on here of anything that even seemed remotely close to my symptoms.

So far I've tested, checked, or replaced the following, and these do not seem to be the cause of the problem:

- Ignition module
- Wires, plugs
- Rotor, Cap (repl)
- Pickup coil
- Knock sensor
- O2 sensor

[Edit: Happened again last night. Driving along testing, all is fine, give it a bit of gas and loss of power, temporary comeback, repeat, then stall. Still no code or service engine light.]

 

I would hook up a fuel pressure gauge, and see what the readings are at your different time intervals, when it will start and not start, just to rule it out.

 

Ohm out your injectors, they could be going bad and overheating the drivers.(looking for 16-17 ohms on all or so)

A crapping out ignition switch can also do the same thing. Gets hot and shuts down let it cool long nouhg and it will run again.

Have you checked the grds on the pas rear of the block, they come loose quite often and seem to have more efeect when hot.

later
Jeremy

 

Assuming your fuel pressure is OK, WAG would be an ignition module as 3.8TransAM said. Here is a trouble shooting guide from trickster:

https://www.thirdgen.org/techbb2/sho...gnition+module

Get all the necessary test equipment ready and drive it around until it craps out and test away.

 

try the injectors this is a common problem and I saw these cars come in with the same symptoms all the time. The easy way to do this is to take the injector plugs off one at a time If one of them is grounding out It will hurt the entire side of the motor since it batchfires. Warm it up and then when it will not start take the wires off one by one. Little advise do not replace just one injector. They get jellous and you will be tearing that plenum off every other week.

 

Thanks. Did some today, got to all but 3 injectors. Cyl #6 gave me 9.4 ohms (hot) and #7 0.2 ohms (hot). Tomorrow I'll get to the rest to see if I have any more.

 

This is very interesting. I'm would like to see what those two injectors (#6 & #7) measure when cold.

 

Oops.

Cyl #6 is right, and it was in the 8.X range when cold.

Cyl #7 was 0.2 when cold, 0.6 - 0.8 when hot.

 

Sounds like you have at least two bad injectors. Don't know if that's whats killing your car, but it is a start. Found this while searching around:

https://www.thirdgen.org/techbb2/sho...tor+resistance

 

Each injector should draw less than 1 amp.
With those values, and assuming the rest are 16 ohm the total current drain doesn't seem right. Any injector, or combination of same bank injectors with a total resistance of 1.2ohms, or less should blow the fuse.

#7 will cause the rest of the injectors on it's bank to fail to open properly, actually the driver's side injector bank fuse (10amp) should have blown.


6 injectors at 12volts/16ohms; 6 * 0.75amps = 4.5amps
#6 injector at 12volts/9.4ohms = 1.28amps
#7 injector at 12volts/0.2ohms = 60amps
Total amps = 65.78amps

 

Before I go further, I'm going to have to address this .

I checked the fuse and its intact. I'll try a different meter, obviously.

Now, assuming I get again that same reading, why would that fuse not blow (obviously you know a lot more about electronics than I and would be better to answer)?

 

your welcome, now get yourself a new set of injectors :-)

Anyhow, as far as the inj. fuses are concerned, its fairly common for them to actually overheat the inj. drvr in the ecm and shut the car down once they get hot rather than blow the injector fuses.

I own 3 of these cars and with friends, have seen this a lot of times. I would say when injectors were failed/failing 99% of the time the injector fuse never blew. The car wouldnt start cold or run horribly or even overheat the inj drvr and shut it down.

later
Jeremy

 

Another question I forgot to ask: If the drivers are overheating, is there any (hidden) damage to the ECM I need to worry about?

[What I mean by hidden is, it starts fine cold last time I started it (Thursday), but is there damage that may not be evident now but be an issue in the future?]

 

I haven't seen an injector fuse blow either, that's why I said it should blow, I believe the fuse doesn't blow because the current drain isn't constant like a dead short.

This is were you would need a scope to see the quality of the signal as it goes from cold to hot.