: Just Won't Start

04-07-04, 02:11 PM
Hi Everyone,
I have a 76 Eldorado 500 Fuel injected convertable. The past few days it was running very rich, black smoke from the tail pipe, and not very smoothly either. Then it stalled not to start again.

I took a look around and the MAP hose had melted through; which I replaced. It still would not start. I have the shop manual and followed all of the proceedures to diagnose the issue. Everything checks! I don't have an analyser to check the ECU, so I am wondering if thats it.

I pulled and cleaned the plugs, which were sooty and smelled of gas. I am wondering if I should pull the injectors to see what shape they are in.

ANY help would be great!

04-08-04, 11:00 PM
It sounds like the MAP sensor made the engine run so rich that it fouled the plugs. First, change your oil, as the excess fuel could have thinned it down. Try to start it after cleaning and reinstalling the plugs. It may not want to start at first-- if it cranks but won't start, try holding the throttle to the floor while you crank. On most fuel injected vehicles, this puts the computer in "clear flood" mode, which is designed to--you guessed it-- clear a flooded engine out. Be ready to remove your foot QUICKLY as the engine may start on the fuel that's left in the chambers. It may idle roughly but should clean out in a few seconds. There's only a couple of tests you can perform on an injector, and while they're useful, they are not the best way to spot a bad one. Only a simulation-type test with specialized equipment will tell you 100% if an injector is any good or not. You usually can't SEE if an injector is bad (unless it is physically damaged). If you suspect they are faulty, I would send them to a place that cleans and tests them (after 27 years, they should definitely be cleaned-- you'll probably notice a difference in performance). Try this place:

www.injector.com (http://www.injector.com/)

They have also done fuel injection retrofits on 500 Cadillac engines.

04-19-04, 08:15 PM
Thanks!, I did as you said and was able to finally get it running rough. After awhile it smoothed out and its driveable now.