"99" 200 Opti Problem

[JCJ]

Serial #0G886121 -- Been trying to figure this thing out for a while now. Motor will crank over fine all day, but will not start. I've cleaned the fuel rails along with checking the fuel regulator, and tracker diaphragms to verify they're good. In addition, I've also replaced the battery, the PCM, rebuilt the fuel diaphragm pump, verified the crank position sensor is set correctly, replaced the fuel/water separator, and changed out the fuel line / bulb from tank to engine. I've also taken some of these components back apart to make sure I did it correctly the first time, and haven't found anything wrong. The only thing I hadn't replaced up to this point (which I thought could be the problem) was the high / low pressure electric fuel pumps. Mine were under warranty so I got another set sent to me, and replaced them this afternoon. The VST looked fine on the inside, and once I got finished, I hooked the hose up, primed the pumps, and then began trying to start. On the second key turn, it started up, and purred like a kitten. I thought "I'll be damn. It was the pumps". However, after letting it idle for about 5 - 10 minutes, it just shut down (like someone turned the key off), and would not start back up. It's doing the same thing as before. It will turn over like crazy, but wont start again??? Any ideas on where to look next??? Thank you.

[lpugh]

Check for proper spark on all cylinders (timing light for a quick test) kv tester for available voltage
check fuel and air pressures while cranking and key on engine off
Do you hear the pumps run for a few seconds every time you turn the key on
Report back

[JCJ]

I do hear the pumps turn on and run every time. What I don't understand is what may have changed when I opened up the VST and replaced the pumps. What changed by me doing that to make it start on the first try, then just die 10 minutes later (like I turned the key off)??? I will check spark, but if the fuel pressure was down, would it even start and run? I was thinking that it would not idle or run well if that were the case? Don't take me asking these questions the wrong way, because I definitely appreciate the advice. Just trying to understand. Thanks again.

[lpugh]

We must determine which system is failing, fuel or ignition, Spark and fuel/air pressure test will lead us in the right direction. No assumptions should be made until these test are performed while in failure condition

as you have experianced, guessing gets quite expensive and very frustrating, with the right test procedures this will not be difficult to solve, though it may require special tools and equipment you may not have access to such as a set of glycerin filled pressure gauges

[RSWORDS]

After verifying you have correct pressures check the CPS.

Easy check is to crank amd look for a reading on the tach (you will have to crank for 10 seconds so the PCM has time to go through it startup)

[JCJ]

So I took a timing light, and checked each coil as the motor was being turned over (trying to start). The #6 coil is not firing. I replaced the coil/cable, and removed the spark plug to inspect (no problems found). However, it's still not firing. I'm assuming this is my problem??? Would having one coil not working cause the motor not to start? I'm assuming this is an electrical issue since replacing it did not resolve. Any ideas on where to go next with trying to identify a coil not working?

[Savage]

Make sure the coil is getting voltage.

[JCJ]

What is the best way to do that?

[Savage]

With a DVOM and a Mercury Manual.

[JCJ]

Well... Got her figured out. After finding my #6 coil wasn't firing during the crank cycle, I started investigating the ignition system. I discovered there are only four components to it (ECU, wiring harness, coils, and Position Crank Sensor). I knew the coils were ok, and that something else had to be causing the #6 not to fire so started working my way down the line. I found a wiring harness and ECU on <Edit- See Announcements> for $100. First I plugged in the ECU, and there was no change. Engine would still just crank over, but not start. I removed it, and put my original ECU back in. I then began the process of removing the wiring harness, and eventually got the one I had bought put on. The engine immediately started up, and has run ever since. I've come home the past three days, and just went out and cranked it to hear it run :). I must have had a wiring issue somewhere in the harness??? Anyway, just wanted to thank everyone that chimed in offering up advice, and getting me going in the right direction. Originally I jumped straight to thinking this was a fuel delivery issue because I had replaced my fuel lines, rebuilt the diaphragm pump, replaced water separator filter, etc... I took all sorts of things back apart inspecting the system (only to never find anything wrong). Thanks again folks!

[MetalliStratos]

Congratulations on getting it figured out!! The coolest thing for me anyway is you learned something new and I will learn from your experience!

[EuropeanAM]

Good find- hope it continues to run well for you.