Background: My battery went bad so I replaced it Tuesday, along with my serpentine belt. Car has run fine since. Been monitoring the volts with the car off and with the car running. Everything was operating fine.

Today I drove the car from work to lunch, then back to work. It sat there from about 1:30 until 5. When I went to start it it cranked but would not start. I checked the battery and it was fine(holding good voltage). I replaced the fuel filter, and put some fresh gas in the tank(just to make sure I definitely had enough gas). Still didn't start. I can hear the fuel pump prime, but I know that doesn't always mean it's going to work good. Right now I'm guessing it's either the fuel pump, ignition control module/coil or the opti. The car is not throwing any codes. What are the easiest ways to test if a)the opti is working, b)the ignition control module/coil are working and c)the fuel pump is working. I have a scan tool/multimeter I can use if necessary. TIA.

 

I would check my fuel pressure if I was you. I had problems with my optishi+ & fuel pump last year, and I think it's your fuel pump.

 

even in the books it says that its hard to test between the opti and the ignition control module

 

Thanks for the replies so far. My first course of action tomorrow is to try to start it with my scantool hooked up. I believe I'll be able to monitor my fuel pressure that way. If not I'll have to get my hands on a fuel pressure guage. Also, I believe that if I unscrew a plug, keep it in the plug boot, ground it to something and watch for spark I can begin to determine if it's the opti or not. I can also test for spark at the coil. I'm also open to other suggestions/ideas.

 

First, check to see if you have any spark at the coil wire. If you do, do the same thing for one of the sparkplugs. If you have a spark, it is not an ignition/opti problem. Then, check the fuel pressure. If you don't have at least 55 psi fuel pressure, then it is a fuel problem, most likely the fuel pump.

 

This will fall in the other suggestions category: Maybe the starter?

 

Lots of good info--->http://csce.uark.edu/~jgbertr/rb/4th_gen_tech1.html

Also, maybe check this.

You definitely need to check your fuel pressure first though

 

more like 38 - 42 psi

 

Yeah, that is more like it.

If you have a spare spark plug, it is easier to use it to attach to a wire than taking one out.

Spark and fuel, like everyone has suggested. That's where you need to start.

You will need a gauge to check the fuel pressure. You can't tell that from a scan tool. When you do use your scan tool, try looking at the rpms when you crank it. If you get none, it could be the opti.

 

Let's keep it simple. It's cranking so it isn't the starter.

Only 3 things are needed for combustion: Fuel, Spark, and Air.

Your first step should be a short burst of starter fluid. If it cranks, it's a fuel problem. Do that before you start tearing everything apart.

Which only leaves spark. Remove the intake tube an check for spark at the coil wire. If you've got spark at the coil... trace from there. If it was the opti, it is unlikely all cylinders would be wiped out at once without warning...

 

yes it is..

its an air/fuel mixture, secondary ignition and COMPRESSION

so lets continue with what 90% of what the other guys said...

any fuel pressure above 30 should get you started...

my first guess is an ignition module... good luck let us know what it was..

 

Do what the other 90% said...? What a jerk. It's a lot easier to give a small squirt of starter fluid to see if it cranks for a sec. Then you know the ignition is working.

Like you said Tofus, you think it's the ignition module. If it runs with a squirt of starter fluid, it isn't the ignition module.

Then check the fuel...

 

im not referring to you specifically wild1

and a fp guage is easier to check on these bitches than removing the intake bellow madness...

depending on your preference of flow chart diagnostics, many methods will work....

lets work together to get this guy some good info... i am guessing on alot of this..without the car in front me.. speculation and an educated guess is all we can give this gentleman..

good luck

 

Sorry about the itchy trigger finger Tofus. No harm.

You can squirt the starter fluid anywhere before the intake. You can disconnect one end of the intake tube (MAF or at the TB - just crack open the throttle blades if your at the TB) and just give a 1-2 second burst. Reconnect the hose and start. It should turn over for about 2-3 seconds.

 

First, I haven't had a chance to hook up a fuel pressure check guage yet, but I have run some other tests.

I checked Shoebox's(thanks a ton for all the write-ups I've used) website, and performed the Opti/Spark Test. Both terminal A and terminal D had good voltage(12 V). Then I performed the test on terminal B while cranking the engine, it also passed (between 1-4V AC). If I read the write-up correctly, then this should eliminate the opti as the culprit correct? The results of the tests indicate that the opti is sending info to the PCM which is in turn sending it to the ICM/coil. So now I guess it's either the ICM, coil or fuel pump. What is the easiest way to check spark at the coil, and if the ICM is functioning? I'll hopefully be getting my hands on a fuel pressure guage shortly.