1991 3.1 AT AC Firebird. New ignition pickup coil(did not fix problem). Ignition module "bench" tests OK at NAPA Auto Parts. Fuel pressure measures 38-40 psi. NO CODES.

After running anywhere between 3-10 minuted engine shuts down. Generally re-starts and dies instantly. I have a datastream readout on my Actron CP9190, but I am not quailified to interpit ALL the data.

What could shut the engine down and NOT leave a code? What data might indicate the problem? Thanks.

 

Disturber Module

 

The igintion stuff did that to my 90 3.1 Auto firebird. Pickup coil, ignition module, and ignition coil all made the car shutoff for no reason. In particular, check your igintion coil. I only found my problem by chance because we working on the car after dark. When I cranked it over, we could see the spark jumping from the middle of the coil to the coil bracket!

Replaced the coil and the car got right back on the road!

Good luck!

 

As I stated in the original post.............I installed a NEW pickup coil and had the ignition module tested. Problem still persists. I ohm tested the ignition coil, it is OK. It is something else.

 

Does it have spark?

Does it have fuel?

The two most basic questions that help determine the problem. If its sparking and not running then your problem is fuel related. This also assumes you have no major mechanical problems like teeth skipping timing chains or broken/bent pushrods.

 

It has spark, at the plugs, when in the no-start mode. It has 38-40 PSI at the fuel schrader valve. It holds good vacuum, right up till it dies(ruleing out plugged cat/exaust). I cleaned the IAC pintle.

The previous owner said he was told the problem is "bad injectors". It is so intermittant, I am hesitant about pulling the upper manifold off, to OHM test them. Because, they might test good, yet be bad. I'm about to resort to said test, I'm wasting too much time.

 

I will take a guess on this one...but it almost sounds like its having trouble going into closed loop?.possibly a dead O2 sensor?.hook up your scanner and see if its actually going into closed loop mode.You can also view the 02 volts and they should be fluctuating up and down rapidly.Now its possible you still have some bad injectors and this is what killed the 02 sensor.I would still check the injectors anyway.Its not a hard task either..I done it so many times I can almost do it blindfolded.If you find some injectors bad..and want to upgrade without breaking the bank..try some Ford injectors?.check the "ditch your stock injectors thread" I promise you these injectors will make a big difference in performance.Hope you get it going again..

 

I removed the upper plenum and OHM checked the right side injectors. All 3 were 0 ohms resistance. Spec is 12-16 ohm, as I recall. "Linder's" Fuel Injection tols me anything less than 12 ohms= bad injector.

I need to order a set of injectors, in the AM. I'm thinking of going with "Linder's" "bosch" injectors, "reman" at 199.00 for 6. I need to pass cali smog, so I don't want to put in high flow injectors. Any sugustion? (no junkyard parts)

 

hey hope you sort your prob, looks promising youve found it. i would seriously consider the ford items as mentioned before in 'ditch your stock injectors' thread. just make sure you match the flow rates and youl have no probs in the smog test.

 

0 ohms on the injectors? Are you sure you had the multimeter set correctly? If they are indeed 0 ohms I doubt that it would run at all, even in open loop. I would double check and replace them if they are bad.

However, don't dismiss junkyard parts! Find any of the chevy 3100-3400 engines with uncracked fuel rails. Pull the injectors out and plop them in yours. Make sure to use a lubricant so you don't tear an o-ring.

 

Ive got (12) 15lb 3.1 injectors I am willing to sell cheap.
6 more 17lb
7 19lb

 

Thanks, but I already committed $200 for six of the Linder's Bosch injectors. My diagnosis better be right!

I too was concerned about 0 ohm reading. I double checked, 0 ohm. I'm gonna triple check, while I wait for 3-day air shipment.

Any chevy 3100-3400 engine? As in 3.1 3.4 litre? Same flow rate and dimensions? I'll try to remember, next time.

PS rockauto has 1 pair Wagner front brake hoses on clearance......$5.34 each. I ordered a pair, this AM.

 

I measured injector OHM's at ambient tempature and obtained readings I'm more confidant of. 9.6 ohms at 60 F. I'll post again, after I install the Linder Bosch injectors.

 

I finished installing the injectors today. The dying problem is gone. Thanks again.