Get this, 25K Mondial t, '89 model with Motronic 2.5. Car has been running FANTASTIC until the other day... A small judder, then just plain DIED at a roundabout in rush-hour. Lots of people honking as they passed having a laugh (all in crap-mobiles and jealous, but at least moving). Cranked away until the battery diet, no starts. The AA (rescue) arrives 45 minutes later, we jump it try 10-15 times - nothing. Accellerator fully down, just a hint of a pickup, otherwise nothing. We give up set it up for a tow, I try, and it starts. By then the coincidence of a ferrari specialist drives by and stops on his way home (Rardley motors who helped me with my gearbox this summer). I warm it up, head for a parking lot to check things over. Everything is fine, idling, warms up etc. Then everyone leaves, and I head home. At the first bit of open road, I put my foot down, and from 1-3K everything is normal, but at the 3.5 K where it is all supposed to liven up, it just trundles along - BUT the intake noise is VERY loud - just growls away like it thinks i is a 430 on steroids... - just doesn't even move as a mondial on oestrogen. It revs all the way up to 7.5K, but much slower than before. All 8 are firing (tried every injector and they all make a difference. Swapped ECU's etc. no diff. I have noticed that if I disconnect the 1-4 bank MAF, the engine runs on 5-8, but if I disconnect 5-8, it dies. So 1-4 are not doing their bit as much as 1.4. If I pulled the fuel pump fuses of 1-4 the engine dropped RPM much slower than if I pulled 5-8's fuse. I pulled all the sparks, and found 1-4 to be a little sootier than 5-8. Rail pressure is 3.5 bar on both side. Took the rail off to look for occlusions, none (though I found a leaking O ring - saved me a fire risk) It has me stumped. All connectors are fine, I plopped two bottles of octane booster and filled it up on Shell Optimax (I always use the premium brand of BP or Shell) went for a long drive to flush the new fuel through - no difference. Today I put on a thick pair of rubber gloves, and pulled the plug cables around the engine. I seem to remember the spark noise being louder (sort of like a firm "TOK-TOK-TOK" sound), but on 1-4 it is barely noticeable... There IS a spark, but barely noticeable... Can there be a situation where there is a WEAK spark? If so, would it be the coil? and would the effect be an incomplete combustion so be overly rich and not make full power? Wouldn't the coil just cut out, instead of just weakening? If so I found the BOSCH part and will only cost £40. I know it is not the spark plug cables as I swapped them over and it made no difference... Marco
Took the bloody thing apart, and here is what I found... Though it does not explain why the whole car shut down, then after trying for 45 minutes it started just fine... So here is the wrecked cat (I need to check the other one). I think it happened a while back as I have noticed the exhaust smelling more over the last few months. I wrote a post on how to cross wire two MAFs into one when the left cylinder bank one blew, and I had a glowing red 1-4 bank cat (http://www.ferrarichat.com/forum/showthread.php?t=202342). This must have done the bulk of the damage, then vibration the rest, concluding with it blocking the exhaust 2 days ago. These were magnaflow 200 CEL cat cores that I also wrote a post on how I fitted them (http://www.ferrarichat.com/forum/showthread.php?t=212160). I am going to check the left unit, though I think that should be OK... I will replace the cat in a couple of weeks. Well on the road again and no F-tax... In this I found a leaking o-ring on the Cyl 4 injector - saved me a fire.... Marco Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
When car hot everything expanded and it can plug. Upon cooldown get contraction and just enough exhaust unrestriction to run poorly. Then back on the gas and the cat is a restriction.
Good find Marco! Why replace the Cat? How about you remove the other side and "gut it" like this side and put it back together? Free fix. Great to hear you caught that leaking injector oring!
Marco: Glad you found the problem so quickly and no damage was caused. Wish you and yours a very happy New Year. Best, Scott
my speculation for you to check: I think you originally had a bad/intermittent crank trigger or similar problem, which caused the car to die and need a tow truck. Then during the diagnosis, with car running on one bank, it ruined the cat, which has nothing to do with the original problem. This is worth considering. Jay
Yup that is the metal core... I will replace though, for environmental reasons... I can't go to the office smelling like a gas station attendant every day. Besides, the high hydrocarbon content in my "scent" seems to trigger all the sensors at Heathrow's terminal 5 security checks (the sniffer models) as if I am ticking... and I'm tired of the special attention. Thanks fos the suggestion of the core being damaged during the diagnosis... I don't think so. I remember the time one of my MAF's blew, that was the same side as the blown cat. The exhaust note changed then and I was somewhat puzzled. I guess it was when the core collapsed and the exhaust gas had to go around it. I expect vibration and temperature change, loosened it completely and it then blocked. The fault the other day happened about 5 minutes after starting, and the whole engine was dead, not just half a bank... M
