I have an intermittent miss in my car. It started when the car got wet at the Reading Concorso. I let everything dry up figuring something/connection got wet. I've driven the car a few times and the problem is always the same. The car would start fine, run great for about 1/2 hour. I'd be driving along and without warning..boom..the car would begin to miss. It doesn't feel like a whole bank goes down... just a few cylinders. After doing a search, it seemed the coil control modules were the culprit. I replaced the modules yesterday and wow what a difference,.... initially. The car ran better than it ever had before.It sang right up to the redline. I had forgotten how much fun this car is to drive. I drove it longer than the normal time it took for the miss to occure and thought I had fixed the problem. Just as I'm ready to get back to the house...boom..... the miss reappears! DAMN! Any ideas on what it might be? Thanks, Will
Bad plug wire or plug extender woud be where I would focus some attention? Definitely souds electrical- Chris
I had a similar problem recently. Started with intermittent miss then an entire bank went down. It was a burnt spark plug extender. Pull your extenders one by one and check for a small burn mark on the inside and/or outside of the cone extender. I replaced my bad one and all was well. I now keep 3 extras in the back of one of my seat covers. Dan
thanks, I had the wires replaced about a year ago. PO had taped up a few of the extenders with electrical tape so I replaced them also. I didn't think it was the extenders as it seems heat related..as if something is getting hot and once it does, the problem occures. The extenders are easy enough to check, so i guess I'll start there. I keep a few on hand just in case too. Thanks for the advice. Will
It's not the extenders. I took them all out and checked them. Just to make sure I wrapped them with electrical tape. Any thoughts on what else it might be?
I would suspect plug wires. I replaced all of mine a couple of months ago and it cleared up a lot of issues with running smooth. I installed the 8mm Accel wires with no problem. While I had the dis/caps off I cleaned the contacts real good and hit the rotor with a little sand paper while it was still mounted. The car runs much much smoother. J
Beleive it or not, I had a similar problem. It turned out to be of all things, a bad connection on the pos and neg battery terminals !! Just like you, I had recently driven the car in the wet, rainy club event. It seems as the engine runs and the ignition and other accessories draw power, and the alternator cannot keep up due to insulating corrosion, the voltage drop causes the second digiplex and or coil to malfunction and miss. Anyway, upon thourghly cleaning the corrosion (that thin shiny black kind, that you don't see between the posts and terminals) and putting a full charge on the battery, problem solved. You may want to check ALL of the grounds on the engine and ignition also (Ferrari ain't famous for robust grounding). Mine actually caused a backfire that blew my intake tube connection off the CIS/plenum. I had inner wells out, ignition sytem apart, coils reversed, wires and extenders...all that stuff. Then I checked the voltage on my near new battery, 9.1v ! and found the culprit. I know it seems too simple but check it out, my terminals "appeared" to be clean and shiny like the rest of my car.
if that doesn't work take a look at the insides of the distributors... I have a slow oil leak at the back of the rear distro that causes oil to collect and cause the rotor not to make a good contact....
Hey, Thanks for all of the responses. I cleaned the terminals and the ground near the battery..no change. I did notice that there was a spattering of mud on the top of the battery, I guess from the Reading Concorso. I haven't had the time to look into the dist. cap yet, maybe today? Still misses. Thanks.
Go Figure??? As mysteriously as the miss arrived..it went away. Jimbo, I took your advice and took off the dis. caps. No signs of oil in there. No carbon tracks. Minor carbon buildup on the rotors and wire contacts. Cleaned them with a file. Initial startup after I put it all back together, unlike before, it missed right from the start, sounded like it wanted to die out......Damn!. I let it warm up in the garage, gently raising the rpms and after a while it settled down to a nice even idle???? I took it out for about an hour and a half drive and it never missed a beat??? The car is running great now! Keep your fingers crossed. I still would like to know what caused the miss in the first place? Thanks for all of the help. Will
Sounds like a classic case of moisture in the dist cap... Could also be carbon tracking that occurs in more humid conditions but you said you checked that.
I'd bet your battery now has a full voltage charge, and did not before you cleaned the terminals and ran the car with a good charging connection.
Mike, There wasn't any moisture inside the caps. I was hoping that was the case as it would have been an easy fix. Thanks. Luigi, You may be on to something? I had a trickle charger connector attached to the battery. One that allowed me to charge the car while it was in the garage. There were 2 wires attached to the terminals, with the connector near the grille so I didn't have to raise the front hood to connect it. When I cleaned the battery terminals, I removed them. They might have been shorting out, although there wasn't any sign of exposed wires? I'm going to take it for a spin this evening when I get home from work. Just to see if all is truly OK. Mille Grazie
Update, The miss came back...I finally got tired of screwing with it and sent it to the shop. So far they diagnosed a vacuum leak somewhere going to the warmup regulator and the throttle cable can't be adjusted? Could these two thing cause an intermittent miss?? Maybe the WUR, but the throttle cable? The cable has some play in it, maybe a 1/8"? What does that have to do with a miss? Both seemed fine the other day when it was running right? Comments are welcomed. Thanks, Will
mine was dropping half a bank intermittently.... turned out to be bad crank sensors. A vacuum leak sounds very plausible... throttle cable not so much. I drove mine with a severely frayed cable for like a week with no issues related to engine performance whatsoever. That warmup regulator may just be the culprit though if it's leaking internally.
Hey JB, How's it going? Yeah, I didn't think the cable had anything to do with the miss. The play in the cable allows a little freedom of movement before the Italian cruise control kicks in. <grin> They are keeping the car over the weekend. They want to start it cold on Monday morning to see what happens. The WUR might be sticking? I still think it's related to the electronics..crank sensor sounds likely? Although this doesn't behave like a whole bank is going down, just a few cylinders. We'll see what they say on Monday? Thanks, Will
Mine had a misfire and I followed some posts on here which led me to the two main electrical connectors that go to the ECU but are in the engine bay on the left (looking from the rear) between the coils and the rear damper mount, cleaned the terminals and a spray of WD40 and the problem went away
I bought my Mondial with a very small miss to it. Did an extensive 30k thinking we would solve it there. Still a slight miss. Turns out it was a small leak in the intake manifold.
A tiny crack or leaking intake manifold causes a miss that can be very hard to diagnose in some locations. One stumped me for months.
I have had crank sensors do this, it drove me crazy trying to get it to act up when I was ready to look at it. Turns out mine worked until they were heat soaked then caused problems, intermittent miss not on any one cyl but moving one to the other. Larry
Update, The shop called and when they went to start the car cold they determined the WUR is not performing correctly? They said the car is running lean? Funny, when I started the car the other day I could smell unburt fuel? They want to fix this and the THROTTLE cable..for the life of me I don't know what that( the throttle cable) has to do with the miss? The WUR is no longer available from Ferrari, they can send mine out to be rebuilt, it will take a week. The total for this and the diagnostic work so far would be $ 1,500.00. When I asked if this would clear up my miss..they said it should, but we don't know for sure. We need to fix the obvious first and then if the miss is still there we can look at that then? Does anyone know where i might be able to get a WUR for a 1986 328 GTS? Thanks, Will
Update : I've been out of the country for the past 10 days, so I haven't had time to devote to this problem. I drove the car back from the mechanics and again it performed flawlessly for a period of time. Much longer than before. Still at the end of the day the miss came back. Now I'm getting frustrated. I did order a new WUR from Ricambi this morning. WOW, $ 800.00 plus shipping of $ 15 and change. This was for a NEW one never used in any car. I figured it is an investment. I'll install it when it gets here and I'll try to document the proceedure, although it looks very straight forward. One funny thing is, the mechanic at the dealership didn't understand why the other mechanic removed the driver's side carpet when he was working in the car. When I explained about the special "Italian" cruise control in our cars , I got a big laugh from him. Evidently he wasn't aware of that option. Will PS. anyone here changed their own WUR?
I've removed/cleaned/replaced several WURs on other cars, not Ferraris, but it was the same Bosch system and the identical components. They are very simple internally and easy to disassemble/clean/check. I've seen one with a broken internal wire that controls the bimetallic strip - easy fix, and two that had deposits around the diaphram that prevented it from sealing - again, another easy fix. It's hard to imagine what could actually go wrong that can't be fixed as opposed to buying a new one but I guess it's possible. Since the same injection system is used on lots of cars, I suspect that a new WUR can be purchased for considerable less than $800, but again, I have never purchased one so I don't know. Of course, whether it is the cause of your miss (overly rich) should be able to easily be determined by disconnecting/blocking the fuel line to the WUR and see if the miss goes away. The WUR is only useful during warm up. At any other time, it is just something to cause a problem! Good Luck
Mike, Thanks for the insight. The NEW , WUR is for the 328 specifically. I don't know if there's a replacment part that would be less expensive? I could have exchanged mine for a rebuilt unit for about $ 400.00 ,but I figured it would be better to get the only New one available? I just hope that the diagnosis is correct. I hate to keep throwing money at it and not really solving the problem. The mechanic did mention something about the wire in the WUR, as a suspect? We shall see. Will
