?ignition break up starts at 4500rpm

[Detomaso71]

I have a ignition break up issue that starts right At 4500 rpm and the rev limiter on the fast and bob bailey are set way above that. I have replaced coil pack and module and plugs. Even borrowed a friends coil pack module to be sure I didn't buy a bad one

Car has new fuel system and logs show appropriate fuel pressure at boost and ignition is standard GN coil pack module and bob bailey box and fast XFI

I had a local GN "veteran" drive car who thinks acts like a coil pack issue but again I have used 3 different coil pack/modules in last month and no difference


How do I unplug or by pass the bob bailey box to run
car without it to eliminate it as culprit?
Anything else it could be?
Car ran great in BG last October sat over winter and the problem was there after winter and both street and race tune are doin it on different types of new gas and all tuning was by Cal

I unplugged both plugs ins on bailey box but then will not start so I'm trying to eliminate it and attack the problem by elimination method

Thx

 

[Lil Truck]

If your talking about the BB 2 step you have to do 2 things. At the fuse panel by the E brake you will find a jumper fuse going to the ECC if I remember correctly. Unplug the unit with wires and remove the fuse and put the fuse back in to the ECC fuse position. Then go to the passenger side and remove the ECM from the kick panel. remove the top cover where the wire connectors are and look for a spliced wire. I believe it is white, you have to disconnect the spliced in wires going to the 2 step and re connect the white wires together. Now the car will run.

I have been chasing a similar problem and it seems to be better after disconnecting the 2 step. I also replaced my plugs and will be trying .020 gap on the dyno today. Test runs on the street feel much better!

 

[Lil Truck]

My first change was the valve springs. I have Champion irons with the flat tappet cam springs, changed them out to a higher seat pressure and spring rate. It did not solve the problem but the rpm range and hp increased above 5k.

What type of cam and springs are you running?

 

[Detomaso71]

It's a new engine hydraulic RPE
Ran great before sitting over winter
It acts just like a bad coil pack

 

[Detomaso71]

Entire car and all accessories are all new and again all ran perfect in BG before I put it away for winter

Looks like I may miss BG this year as I am struggling figuring this out

 

[TurboBuRick]

Did you try batch fire? Cam sensor stock? Are all ignition components ac delco?

 

[Lil Truck]

Did you try batch fire? Cam sensor stock? Are all ignition components ac delco?

I have 2 sets of AC Delco Ign mod & coil both ran the same. Re checked the stock 40k mile Cam sensor settings and condition all were good. Can you make a full WOT pull in batch with Alky and not hurt anything?

My car runs perfect, you would never know it has any problem except around 5k in 3rd gear WOT. The RPM dips about 300 rpm on the dyno, the continues on with milder dips to 5700.

 

[Detomaso71]

Cam sensor is new stock replacement 2 yr ago
All AC Delco

Not sure what batch fire is?
My Alky is off and car is set around 8 pounds boost on 93
All the testing on low Boost to avoid damage

Anyone know how to disconnect bailey box and run car ?
Lemme know how to do batch fire again not aware of that?

Thx

 

[Lil Truck]

Batch fire, start the car and then disconnect the cam sensor at the connector while running. You have to reconnect the sensor to start the car again.

I told you how to disconnect the bailey box above.

 

[Lil Truck]

If your talking about the BB 2 step you have to do 2 things. At the fuse panel by the E brake you will find a jumper fuse going to the ECC if I remember correctly. Unplug the unit with wires and remove the fuse and put the fuse back in to the ECC fuse position. Then go to the passenger side and remove the ECM from the kick panel. remove the top cover where the wire connectors are and look for a spliced wire. I believe it is white, you have to disconnect the spliced in wires going to the 2 step and re connect the white wires together. Now the car will run.

I have been chasing a similar problem and it seems to be better after disconnecting the 2 step. I also replaced my plugs and will be trying .020 gap on the dyno today. Test runs on the street feel much better!

If you have a Bailey 2 step box read above to disconnect it.

 

[Detomaso71]

Thx!
Will try all this Tuesday pm after done with my shift an get back to you

 

[Lil Truck]

If you are running the 2 step what RPM is it set at? and where is the activation button? Could it be activated? Bad switch?

 

[TurboBuRick]

No problem doing wot pull in batch fire.

 

[Lil Truck]

No problem doing wot pull in batch fire.

Thanks Rick

 

[Detomaso71]

If you are running the 2 step what RPM is it set at? and where is the activation button? Could it be activated? Bad switch?

I have increased trigger and main on two step to 6500 rpm already and on the fast XFI limiter as well recently and no change

 

[Lil Truck]

Well good news!

Just made 2 clean Dyno runs @ 28lbs to 5500 RPM, no hesitation or misses!

We did have a problem with the dyno tack pick up not wanting to register but we got it working.

The only thing I changed from my previous runs was the plug gap down to .020 and disconnected the 2 step.

I verified but never adjusted the cam sensor.

 

[TurboBuRick]

Well that's some good news. Sounds like maybe the 2 step was doing it.


Posted from the TurboBuick.Com mobile app

 

[Lil Truck]

It may have been the 2 step or the plug gap?

There is a lot of wire run in my 2 step installation to keep it hidden behind the glove box and a switch under the ash tray. That may have caused some noise or voltage drop if it was the problem. When I am done with this race season I may plug it back in and see if the problem comes back.

 

[TurboBob]

where is the ground connection? Body grounds are terrible, noisy, etc...... the 2step is designed to handle the noise, all the testing was done with the unit grounded to the nut near the hood release. But some cars are noisier. And some ignition modules are noisier.

Look me up when you want to get back into the troubleshooting.

Of course it could be the plug gap..

Bob

 

[Lil Truck]

Thanks Bob,

I will get with you when I test it. I believe I did go to the nut by the hood release I will let you know.

At the Dyno shop we continually had problems with a good tach signal. He even bought a new shielded line with ground connection. We the ground was connected no signal at all? With out the ground it was inaccurate.
We had to go back to his non shielded line and attach close to the spark plug to get a good signal. Dyno Jet system.