Alfa Romeo Forums banner
1 - 13 of 13 Posts

·
Registered
Joined
·
296 Posts
Discussion Starter · #1 · (Edited)
87 verde engine in 83 GTV6.
Driving on the track at the national event in Detroit.
Out side temp 95 degrees. During practice session, car ran great for the first three laps. Then it started to cut out in the hard right hand turns. It didn't sputter or lose power, it jut went dead like a switch went off. Drift through the corner and straighten out and it would come on as quick as it went off.
No problem in the left turns or straights. Parked the car and it idles perfect, engine temp never above 175. Gas tank over three quarters full. Wiggled some wires on the fire wall, found a loose connection and secured it. Took the car out for second practice and it ran great for three laps and again cut out in the right hand turns. Parked the car and it idles and revs fine. Shut it down and waited for the time trials. About one hour later ran the warm up lap and first hot lap without a problem, actually set my fastest lap of the day, on the third lap it started again cutting out in the right handers. Drove the car 20 min. back to detroit without a problem.
Next day drove to the auotcross, ran the first three runs and then it all started again, cutting out in right hand turns. Then drove the car 5 hours home on the freeway without a problem, did not take any exit ramps hard enough to make it cut out. Can't be a fuel level problem, why ok after sitting for 1 hour. Not a fuel pressure problem, pulled inertial switch and engine doesn't cut out so fast, fuel rail still pressurized. Any suggestions would be helpfull.
Jim
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #4 ·
Is something happening with your throttle cable as the engine tilts as you go through the turns?
Throttle cable is OK. The thing I can't figure out is each time the first few laps were OK then all of a sudden it would begin cutting out.
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #6 ·
Thats odd, it might be a loose ground or something hard to trace, also a battery wire? AFM flapper? maybe the spring is worn. Sounds like you have quite the hunt ahead of you. Good Luck
battery and cable secure. I would expect a flapper problem to be progressive. This cuts out like a switch, completely off then on.
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #8 ·
My first suspicion is electrical due to quick on/off. Either loosing spark or power to the injectors. My first approach will be a through review of all obvious and not so obvious electrical connections. I plan to autocross the car in the comming weeks. I think I'll rig up my timing light and secure it in the passengers seat to monitor the spark. If it acts up again and the light stops flashing, I'll at least have narrowed it down a bit. If spark continues, I'll examine the fuel delivery system. (Also noted that the idot lights on the dash do not come on when the engine dies.)
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #9 ·
I know squat about Milanos - but it does sound like a loose ground or wire. Are there any important electrical grounds on the right hand side of the engine bay? I'd think with pulling a hard right the G-forces will want to pull things to the left, perhaps something on that side of car is pulling away from it's ground or lifting into contact with another wire or ground and causing the shutdown.:confused:
On a brighter note - at least it's fairly consistant :D usually, they're more Mercurial in their habits!
My first thought also, but why does resting the car for a time eliminate the problem for a few laps? That's what has me stumped
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #15 ·
Does your tach drop to 0 at the same time, while the engine is still turning? If not, it's likely not an ignition issue as the tach reacts to spark timing.

Just my 2 cents.
Did not notice if tach dropped. If I was loosing just spark, and the injectors were still working, I would expect a backfire or exhaust pop when it refired. No such thing occured, just instant silence and then instant power upon exiting corner.
The battery ground should not be an issue. The battery is properly secured and terminals taped. A functioning alternator develops the electricity for the system when the engine is running, eliminating the battery ground as a source of the problem. All the grounds in the engine bay have been checked and cleaned several times. I suspect that the harness supplying power to the spark box and or injectors is grounding or loosing power. After all, the mechanic that installed the 3.0 L engine and the harness (me) is known to make mistakes. But the engine was installed 3 years ago and this is the first time this particular problem occured.
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #17 ·
How about a fuel pump problem?
You know that thing hangs underneath your car there, and is subject to some forces... I've had an intermittent fuel pump once, but they're not cheap.
However, I'd expect it to stutter or not be smooth right after this happened...

Perhaps your ECU connection? I've seen that one fail a number of times.
The fuel pump connection was the first thing I checked. Also if I pulled the inertial switch, the pump shut off but the engine kept running for a little bit due to residual pressure in the fuel rail. Not an instant cut out like on the track.
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #21 ·
Jim,

I've had two GTV6's with this exact same problem so I feel your pain. I called my friend who is an Alfa mechanic and he told me it could be a couple different things. On one of my cars, it was the oxygen sensor wires on the passenger side of the firewall that were rubbing on something and shorting out. On the other, it was the 6 prong? modular box that hangs upside down by the steering column. It has a fat green wire going to it. If your car has had rust issues around the windshield, water can get in here and cause some havoc.

Check these two things out and hopefully you'll find the issue. I'm no mechanic, but I hope that helps.

Marco
Marco,
I just put on a new exhaust which included a new O2 mount, AND I have a hole at the base of both A pillars. I'll check them out. Again the thing that I cant understand is the three lap delay before it acts up. Maybe a red haring that is coincidence.
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #35 ·
Thanks for all the suggestions. The first thing I checked was the fuel pump connections. All were ok, I then pulled the inertial switch under the hood and the pump did shut off but the engine dies a slow death as the fuel pressure in the rail drops. On the track the engine would cut out instantly and come back on just as quick after exiting the turn. While in the turn, I kicked the fues box in frustration and no change. I did not notice if the tach died or not. I also considered a short in the sterring column. Wiggling the key in the turn made no difference and turning the wheel to the right while in the pits did nothing. Asle driving the car on the street though rt and left turns including off ramps failed to trigger the shut down. It is only with heavr lateral G loads, 2 to thee laps worth before the gremlin appears. I am discounting the time element because I can't imagine any component that is sensitive to latertal loads and time and/or temperature. Will go over the wiring in the next week and plan on autocrossing the car in the comming weeks. Hope to sort it out.
Jim
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #36 ·
Some clarification is needed. I do not recall if the tach dropped to 0. I was too busy watching my mirrors as to not hold someone up. And the steam coming out of my ears was fogging up my helmet!! I did wiggle the key and turned the wheel back and forth a little thinking it might be in the sterring column but it did not help. I also kicked the fues box in frustration.
If the tach does not drop to 0, only drops with decreasing engine RPM, would it be safe to assume I'm loosing power to the injectors?
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #40 ·
Engine is dying suddenly during right hand turns. Personally, I'd forget what's going on with the tach when it happens, I'll wager the driver wasn't paying enough attention to the tach for it to be a factor in the diagnostics.

In my experience, when an engine dies abruptly, it's electronics, not fuel. And when an engine dies during turns, the most likely electrical cause is some kind of stress on a wire that would be affected by whichever direction the engine would be stressing it. In this case, a right hand turn, the engine is leaning toward the left, stressing the wires on the right side of the engine.

Until I'd eliminated them, I wouldn't spend a lot of time looking elsewhere.

And it should be pretty easy to eliminate them, they're all pretty easy to get to.

Just looking at the most obvious behavior first, and based on what I've heard, it's the right hand turns.

bs

While at the track, I inspected the plug a the base of the distributor, plug to AFM, grounds to valve covers, and all the wires on the pasengers firewall. One wire was loose in the two white plugs, fixed the spade connector but the problem persisted. My trackside inspection consisted of jiggiling the wires and plugs while the engine was running, not very scientific, but the best I could do in 95 degree heat. I plan on revisiting all these and also the spark box and ECU. I doubt I'll get a "gotcha" momment, and find the problem, I just hope it will be solved and assume I cleaned the offending connection.

Jim

PS My guess is I'm loosing juice to the injectors or the whole harness. If I was loosing just spark while the injectors continued to function, I would expect a backfire when all that raw fuel got ignited upon refiring.
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #43 ·
also check the battery. is it clamped down good? I have seen where a battery coming lose with nothing to keep the charge going like cap in a rado etc to cause problems. it is common for the voltage to also jumo to 100s of volts if the battery comes undone. some ecus fry and some shutdown. also might try jacking the car to a 40° or so and see if you can get it to stop.
Battery is clamped down and positive terminal insulated and taped per AROC competition rules. "Jacking the car to 40 degrees"? Do you mean tipping the car to simulate lateral load,..... and then starting it up? Sounds risky to me. If the car is 6 ft wide, that would mean lifting the side aprox. 4 feet!
 

·
Registered
Joined
·
296 Posts
Discussion Starter · #47 ·
fixed?

I have put about 300 miles on the car driving back roads without a problem.
Examined all connections to distributor, injectors, AFM, ECU, and harness and did not find anything that looked like it would have caused a problem. I obviously did not push the car as hard on public roads as I do on the track, so I'm not sure if it is fixed. I was unable to attend the local autocross last week due to work schedule. I'm looking for a fall track event to test the car. I'll keep this post marked and update it when I get some info. Thanks for asking. At least it's reliable on the street.

Jim
 
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top