Hello,

I've recently been trying to get my Camaro running again, its an 89 TPI 350. I explained my troubleshooting in this thread:

https://www.thirdgen.org/forums/tech...-89-350-a.html

After reading the following thread:

https://www.thirdgen.org/forums/tech...r-driving.html

I went back and checked the injectors. 6 Read between 16.1 and 16.7 ohms. The other two injectors read 8.9 and 11.5. Should I swap in a new set of injectors thinking that is the most likely problem? I tried disconnecting the two out of spec injectors, and cranking but still no start. Should I be able to get the car to start up and run poorly on only six injectors?

Thanks!
Martin

 

Well, I got my old 'formy to run on seven when one went dead short, (0 ohms). Check your FP.

 

Martin, your car should start and run (although not very well) with 6 injectors. If you know two are bad, it's worth replacing them all. That said, it might not be the cure all you're hoping to see.

Mike

 

Thanks guys for the quick reply. I'm going to make my next step replacing these injectors. If this doesn't fix the no start its at least another issue knocked out.

Fuel pressure should be good, a guage on the rail is saying around 40 then spiking up when I crank ( which I think may be strange isn't it supposed to dip or at least stay constant?). It stays pressurized for at least minutes after also so no leaks.

I did get a chance to check the injector pulse using a scope tonight. It looks like its supposed to according to

http://www.autodiagnosticsandpublish...or-testing.htm

So at least I know the car is trying to fire the injectors. I'm hoping maybe some more of them are stuck in a weird way etc, and a new set will get it going. If not I will just keep troubleshooting. I'll keep the thread(s) updated in case it can help someone else. Please keep the ideas comming though.



Thanks!
Martin

 

without a doubt you need a set of injectors. if one is bad, the others aren't far behind.

i noticed the data log in your other thread.
9.4 volts to the ECM is too low under any conditions.
the ECM won't work properly with the voltage that low.
it needs to see a minimum of 9.8 volts.
toss in the bad injectors and the problem is multiplied.
with good injectors, the ECM will see around 6~8 amps of current.
with the 2 bad injectors you have, i would guess (im too lazy to do the math right now) your ECM is seeing around 10 amps or so.

a few years back i have had an intermittent problem with my car. occasionally it wouldn't start. hit it with a battery charger or jump it with a running car and it would start right up.
it turned out to be a bad ignition switch.
one day a few months back it died a few times while cruising at steady throttle. i decided to turn around and come home. a couple of miles from home it died and wouldn't restart.
after i got it home i found it had no injector pulse. the USB port was bad on my laptop, so i couldn't look at the data.
after a couple of hours of trouble shooting, it fired up out of the blue.
i didn't fix anything, so i didn't trust the car.
a few weeks later i wanted to go to the store for some smokes, and it wouldn't start again.
i had picked up a PCMCIA USB card for my laptop and got it out and took a look at the data. 9.2~9.6 volts cranking. i ran a jumper from the battery to the ECM and hit the key, the motor fired right up.
its so intermittent right now, i don't know if i have a wiring problem or if the switch is bad again.

 

Denn,

I like your line of reasoning. I wasn't sure what the car would like to see while cranking (figured the voltage should drop, but by how much who knows). I'll run a test where I'm gathering data with the two injectors unplugged, and see if the voltage peaks up. I did order the new injectors (from a board sponsor) so I may just wait until the show up, swap them out and test again.

I will also go through and check all the grounds again, maybe some connector is corroded. It has been sitting. At one point the fans wouldn't turn on, I was dropping something like 5 volts across that fan connector by the battery. I couldn't believe how a big a difference just cleaning that connector made.

Thanks!
Martin

 

Well, I finally got the new injectors into the car over the weekend. It started right up, so I'm pretty happy. I swapped out the EGR valve too while I had the intake off. It is a big relief to have it running, now I can work on getting it running right. I also replaced a lot of the vacuum hoses, there were leaks everywhere...

Thanks for all the comments, as always they were helpful.

Martin