Need help on a 1984 Mondial cab. US model. The car is running sluggish. It can not climb hills it used to thrive on. The slow down engine light comes on at 60 mph or on accelerations. The light is on for a very short time. If I let go the gas pedal, the light goes off in a second or so. Per similar posts I read on the forum, the Slow Down means the cat getting hot. Though I could not find a definite fix, other than a fuel/ignition problem. I placed my hand on the exhausts. The one on the passenger side is quite hot at idle. The temperature gauge is below 194. The exhaust does not appear to be in consistent "blows", like one "blow" appears to be missing. History: I did a major on the car which lasted all summer. Belts, valves, valve seals, etc. While at it: I replaced the fuel filter, hoses to the fuel filter, and the ignition wires. I also used DeOxIt to clean all the connectors in the ignition and fuel injection. My mistake, I should have done one at a time, as now I do not know if to look at ignition or fuel. The car took some time to start, as the fuel lines and filter were empty. Could this have caused any isses of air lock? Could something in the fuel line clogged an injector? Would having the fuel lines dry for 4 months have caused something to "seize" somewhere? Assuming fuel is the case: Should I just fill up the tank with Techron and try it again? On the ignition wires, I installed Accell 4040R (7000 Ohm per foot), as other folks did. I bypassed the black extenders as the wires have the extra resistance. I use Iridium plugs. Per other posts that did this, they did not have any problems. All plugs and wires are securely connected. I cleaned the distributor and rotors. The center carbon spring on the distributors appeared to be fine, though I did not replace them. The Cavis wires were hard and brittle; some broke during the replacement. I can not go back. Any leads on trouble shooting is greatly appreciated.
Wonder if you have a bank of cylinders out. If your slow down light is on that means your cat is overheating. This generally occurs from raw gas getting into the cat which is a symptom of a bank out. Check to see if both banks are firing. Get a spare plug. Remove a spark plug wire on one bank and connect plug to it. Ground plug to block. Crank. If it fires, test other bank with same test.
Richard, Do you have one cat or two? I'm not sure when the changeover was. You phrase it like there is only one light, so that should indicate just one cat. Placing your hand on the exhaust outlet doesn't mean much, especially on a single-cat system where everything is mixed together way before it hits the muffler. In any case a super-hot cat means fuel is burning in the cat instead of the cylinder(s). (I worked on a GT4 that had a bad rotor and had a dead bank. Amazing how smoothly it idled, but no power to accelerate.) I would go all over the ignition system before looking at fuel. Fuel is being delivered, but it is not being ignited in the engine. Are you sure you have the plug wires back in the right places? Do you have a timing light to put on each wire to see if all plugs are firing?
Thanks for the feedback! I used one of those inexpensive strobe light testers. The front bank has solid strobe lights on all the wires. That half of the engine sounds good. The rear bank had two ignition wires with weak strobe lights. When I pulled the two wires out, I noticed that the connector for the plug was buried down the plug insulator. I pulled it up and now it makes a good metallic contact. Though the strobe light is still weak on those two wires. The engine is running much better, but still missing slightly when the accelerator is pressed from idle. Brian and other posts mention problems with the rotors. When I was installing the rear one (the one missing), it went in snug. But when I pressed it more to double check, it went about 1 mm further in. The center carbon with the spring in the distributor only goes in and out about 2 mm. The brass contacts with the screws protrude into the distributor only a few millimeters. The thickness of the new distributor cork gasket is thicker than the old one. Not much room for tolerance build up. I tried measuring the distances of the carbon and the contacts in the distributor and compare it with the rotor against the face of the distributor surface. I was tempted in pulling the rotor out slightly, but the measurements were inconclusive. I can not tell if the rotor is aligned with the contacts and carbon and by how much tolerance. What problems did others find? How did you manage to measure the rotor against the distributor? Thanks again.
I (eventually) swapped the rotor to the other distributor and the problem moved, implicating the rotor.
my slow down light is flickering on and off.....car seems to sound and run fine....what do I need to do..... or worry about?......I am a mechanical novice...thanks john
When my 1988 Mondial cab started to flicker the slow down light, but was otherwise running fine, here's what I did: At the cat, remove the temperature probe sensor (just undoes with a 10mm wrench). Use a small brass wire brush and give it a light surface cleaning. Be gentle, it is an expensive item. In the trunk, on the right behind the carpeted cover (a couple of screws to remove), there is the other end of the cloth woven/braided wire from the cat sensor, that goes into a "black box". This is the ecu brain for the cat sensor. Take off the connectors, there are two bullet type connectors, use some radio shack electrical cleaner, and then put on the some DeOxit or Stabilant to ensure good connection. If you are inclined, put DeOxit on the relays and other connectors in there, probably prevents other electrical problems. This worked for me. Of course, it could be something more serious, but if the car runs ok, flickering means it is simply the connection. The sensor or the ecu itself might be shot, but not much to go wrong unless the wire is cracking (it does take alot of heat), which you would spot visually. If it is the cat ecu, more big bucks, but it does serve an important function of letting you know if a bank of cyliders fails (probably from a coil failure, which is not that uncommon as the cars age), and raw gas pumps into your cat, potentially causing a serious fire. Such is the price of a racing design with two distributors...
