Testarossa Cold /idle ok but car stutters when engine is hot

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http://www.ferrarichat.com/forum/boxers-tr-m/279017-testarossa-coil-module-thread.html

 

I've done some more testing, and the car is definitely *not* fixed. However, it does run better: meaning that when it breaks, it seems more like the definition of one bank going out, in that it will idle, with some difficulty, at 500 RPM. I could drive it very, very slowly. Given that replacing the drivers ignition coil brought it up to this level (see my ending posts in http://www.ferrarichat.com/forum/boxers-tr-m/553016-help-please-car-dying-stops-after-major-2.html), is there a good chance that the passenger ignition coil is bad as well? Would that be the easiest thing to check by swapping it out with a good one? Car starts up just fine, but goes to pot when she gets hot.

 

Also, can't rev up engine when it gets in degraded condition. Most I could get was 2k RPM. Engine is almost pulsing, or sounds like heavy breathing, oil pressure needle starts vacillating, along with battery light blinking.

Took it to grocery store last night (~ 1 mile away), short-shifting all the way, almost made it back home before it started acting up. Could go on level road somewhat OK (very slowly), but had real difficulty trying to go up hills. Periodically made horrible clunking sounds.

 

Did you also change the modules that sit above the coils? If not, then swap them around and see what happens. If the engine completely dies, then you know it's at least one of your modules.

 

I'll check with my mechanic, but I believe he *DID* change the module, along with the driver's side coil. I've ordered a coil UF-136 from oehq.com and will have him install it on the passenger side. If that doesn't work, I'll have him swap the modules and see what happens. Thanks for the input, Sam.

I drove it again today, *twice*, around a loop starting in zip code 90025 Stoner Ave, just south of Wilshire Blvd. to Texas Ave to Saltair Ave to Wilshire Blvd back to Stoner. When I went to put it back into the parking structure on Stoner, it had just sunk into degraded mode again. Same symptoms as before.

 

Tommy, if your symptoms are anything like mine, then the coil modules could be the culprit. They were intermittent until it became permanent.
Check the vids out.
http://www.ferrarichat.com/forum/boxers-tr-m/529535-87-tr-rough-idle-stalling-surging.html

 

I think my problem is of a slightly different nature, whereas it starts (and runs) perfectly when cold and only starts sputtering when it gets hot.

In case I *do* need to get a module or two, do these look like the right kind?
https://www.amazon.com/IGNITION-EUROPEAN-64833036-064833036010-581701010000/dp/B00C1RL1NK

 

Read the thread I posted in post 26 all the cross reference info is in there. I ordered 2 new ones for less than $100 and leave one in the glovebox that you know works

 

Thanks Jeff. Finally got the UF-1

 

Thanks, Jeff. Finally got the UF-136 coil and took it to my mechanic, but it said it wouldn't fit. After really looking at the setup, it seems the coil won't fit in the old style heat sink, and it would need a bit of a custom wiring harness.

I'm going to get the whole coil/module/heat sink in the newer style from what I have. When I removed the old unit, however, I pulled all the wires out of the power module connector. I looked around and couldn't find a wiring diagram for it -- does anyone have one? It is 5 wires into a 7-wire connector: yellow/green, solid yellow, yellow/red, solid black, solid red.

 

Tommy send me your email address I have a few wiring diagrams that might help you.

 

Thanks again, Jeff. Will PM you my email. Just ordered new coil/module/heat sink from AW Italian in New Jersey for about $500.

 

Finally got new coil/module on passenger side installed. (now both sides have new coil/module) Still having same problem. I thought I read that to allow the Testarossa's computers to recalibrate after disconnecting battery, it should just sit idling for 10 minutes. So I was doing that and after about 8 minutes the idle dropped down to about 500 RPM and would choke and sputter when I revved it. Any ideas on what I should check next? Maybe fuel pump relays?

 

your car is a 88 as I read in your profile, so there is a KE jetronic installed, rigth? this car then has no computer or self learning system ( not the european version, US ?? )
does your car have cats?
you have a chance to meassure the exhaust gases ( CO and HC )?
you have an oszi to check ignition?
you can check the fuel pressure with a gauge?

 

Yes, it does have KE Jetronic installed to the best of my knowledge. It is also US version.
Being I live in California, it definitely has cats, and passed smog certification after its recent major service in March of this year.
Unfortunately, I park it in a commercial parking structure, so I am very limited as to the amount of work I can do on it, and don't have a lot of tools, other than basic stuff for working with screws, bolts, etc. I don't have any of the tools you listed above

 

Who did your service? Does the car air often for a long period of time?


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F&M Motorsport in Los Angeles. Not sure what you mean by "air often"??

 

Iphone type, i meant does it sit for long period of time?


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LOL, ok, understood. No, it wouldn't sit longer than 2, maybe 3 weeks without some kind of use by me.