[90Brougham350]

Well, had a pretty scare today doing a little routine maintenance on the 90. I replaced the EGR valve as well as vacuum hoses, and seafoamed the EGR passages. I had to disconnect the MAP sensor vacuum hose and unbolt the fuel line for the passenger-side fuel injector. Unfortunately, I was very busy this morning and only had 40 minutes to do the job, test-drive it and make it to lunch before my class. Replacing the EGR valve and vacuum hoses went just fine. Started it up, and it ran like sh*t until the seafoam did her magic. Still running a little rough, and the SES light was on. Checked it, code 33.

I thought 33 was an EGR valve problem, so I'm staring at the thing, making sure everything is tight and connected. I can't figure it out, so I take it for a test-drive, and it runs great! A slight hesitation at about 10% throttle, but great otherwise. However, I'm going through gas like dollar night at a whore house, and get another code, 45. This one I know is a rich O2 sensor.

I get back into my apartment's parking lot and open the hood, can't see a damned thing wrong. I'm still thinking that 33 is an EGR problem. I shut it off, went inside and opened the service manual, when I realized that 33 was a MAP sensor problem. I went out and immediately noticed I forgot to reconnect the MAP sensor vacuum hose! No wonder I was getting a code! Of course, here's where it got fun. I also noticed the passenger-side fuel injector line was disconnected. It was up against the side of the throttle body, just pumping fuel out at 11 psi the whole test-drive and parking lot idle, a good 10 minutes!

I didn't think anything of the enormous puddle that formed as soon as I started the car, because I spilled so much Seafoam on the engine trying to get it down into the EGR passages, I just figured it was Seafoam hitting the ground. Well, I guess that explains how I went from 3/4th of a tank of gas down to 1/4th in less than 10 minutes......

The thing I can't figure out for the life of me is how it ran so well with only 1 injector getting fuel. I mean, it ran damn well! But, problem fixed. MAP sensor reconnected, fuel line re-attached, and only a half-tank of gas on the ground, lol! My story.

 

[caddycruiser]

Wow, sounds like a fun morning

So, did you get the spark knock/pinging problem solved yet?

 

[90Brougham350]

I did, actually, I'm surprised you've remembered! I have 3 exhaust leaks that I've isolated and had a very hard time finding. Davesdeville was right, it was the exhaust. First one is where the driver's side exahust manifold meets the y-pipe. I couldn't see it or hear it when the engine was idling, but discovered it only leaks under throttle. I saw it today while I was Seafoaming, I saw the little leak and white puff, but only when I would hit the throttle by hand, and actually give it a little juice. Second leak is very small, it's on the pipe connection where I replaced my cat with a piece of galvanized. Third leak is where the pipe meets the front of the muffler. When they did my exhaust last (before I bought the car), they put an odd piece of pipe infront of the muffler that has a strange bend in it.

By playing around with the windows down and trying different speeds and acceleration and whatnot, I was able to hear each of the leaks today. Much easier to hear them once I knew they existed, lol. The EGR valve I replaced probably didn't need to be, but the throttle is slightly more responsive now. I've also tricked the knock sensor by tapping on the manifold while holding the RPMs probably around 1500. I watched the timing retard. The dreaded death-rattle is gone, and my exhaust is getting a total revamp next spring when I get back from Italy. I've already got some Headman headers on the brain, they should sound pretty good.

 

[caddycruiser]

Good stuff. Like I said before, the "death rattle" was VERY bad at times on my '93 FWB, but it eventually got completely fixed with a new EGR and solenoid.

Had the same problem earlier on with the '92 Roadmaster, and after a few expensive "repairs" that really didn't need to be done, my father is almost certain the problem with it too is the EGR, since the car has 191k on it and isn't feeling so sprightly lately. He eventually got rid of 98% of the spark knock after retarding the timing a little, but told me the other day he was driving down to the beach (ahh...the pleasure of living 15 min away.... ), and started to hear it once again.

He's planning on replacing the EGR himself this time--dealer did it on the Caddy--and is hoping that's what the whole problem is. Guess we'll see.