wilson@potassium.cchem.berkeley.edu (Michael A. Wilson) (02/27/90)
Hi all --- More on the '77 MGB. Well, one problem is definately the choke. Pulling the choke assembly and turning off the choke, and I got the car running ok. Still too rich: lots of carbon on 1, 3, and 4. And 2 is wet. Hmmm. Must not be firing. (Please O great Lucas, don't let it be oil...) Ok, lets get a new set of wires (already switched the plugs around, so its #2 and not the plug). Check the rotor and cap. Let's see, '77 MGB, should be a 45DE4 distributor (electronic triggering). Pop the top and... uh, what are those points and that condenser doing on my new '77 MGB? Looks like Mr. 45DE4 has been switched for a 45D4. Is this legal?... in California?... And I want to check out a rumor. I was told that late model B's, with the catalytic converter located conveniently below the carburetor, are prone to engine fires. The theory is that the heat shield goes, the rubber parts dry out and crack in the added heat, so maybe some gas drips down onto the CC, and presto --- engine fire! Any experiences or comments (uh yeah, make sure the heat shield is in good shape...)? MG's forever---- Mike Wilson
guy@bevsun.bev.lbl.gov (Aran Guy) (02/27/90)
Mr. Wilson says: And I want to check out a rumor. I was told that late model B's, with the catalytic converter located conveniently below the carburetor, are prone to engine fires. The theory is that the heat shield goes, the rubber parts dry out and crack in the added heat, so maybe some gas drips down onto the CC, and presto --- engine fire! Any experiences or comments (uh yeah, make sure the heat shield is in good shape...)? I respond: My '79 Spit has the same setup, and it catches fire regularly. (Well, it did, until the transmission died.....) First it was the cardboard doohickey that goes from the scuttle past the right front wheel. This happened the day I bought the car, and continued until there wasn't any cardboard left. Then the hoses going to the auto-choke went, spraying water everywhere. At least that fire put itself out. Then, on one VERY hot day, I noticed this funny brown spot growing on the hood, while driving on the freeway. As I pulled over, I found the throttle stuck open. I grabbed the fire extinguisher and knelt down by the wheel, and zapped the carb fire from below. (No pesky cardboard doohickey left to get in the way.) The fuel hose had cracked and dripped gas over the heat sheild. The jammed throttle was due to the throttle cable sleeve melting. NEVER open the hood on a potential engine fire! The increased O2 can cause spectacular flare-ups. I know. I've seen a few.... All hosing has been replaced by high temp Tygon tubing. And the innards of that pesky converter... well I won't go into that. Seriously though, As much as I like Britcars in general, the placement of the catalytic converter under the carb and in proximity to combustibles is STUPID STUPID STUPID! It's more than that, it is criminally negligent. If the Pinto had the same arrangement, Ford wouldn't be in business today. Keep a fire extinguisher handy. Don't panic if you get a fire. Replace any proximate combustibles with material more appropriate. And either keep your engine and smog system in tip-top shape at all times, with frequent replacements of suspect components and exhaust- meter guided tuneups, or let your conscience and the smog laws fight it out. I've been lucky. You may not have the same luck. Aran Guy guy@bevsun.bev.lbl.gov