mnmike

I had this problem earlier where I would hit the fuel cut at about 12-13 psi so I bought the 951MAX chips from Lindsey. Basically I accelerate hard, the car hits full boost and then at somewhere above 5k rpms it cuts out. Im still hitting the fuel cut at 14-15 psi. Do these chips have the overboost protection but higher than stock? I installed the 3 bar fpr as recommended. My other mods are Tial 38mm wastegate in dual port mode, 3 inch exhaust, high flow cat, intake and MBC and cycle valve delete. I have noticed on a warmer day the car gets to about 6k rpms with where my MBC is now set. Tonight it was much cooler and the car cut out at about 5k rpms. Is there anything else that could cause this problem under hard accel?

Geneqco

I had a similar problem when I had a bad injector.

rberry951

Hey Mike,

You won't be hitting any overboost protection with the chips. However, did you buy straight out or did you do an upgrade? If you did an upgrade, and it was from Autothority, and you still have the autothority KLR chip? This is the only scenario I've seen this happen. You can use my KLR chip, or even a stock KLR chip, but the authority KLR chip causes issues. If you have our KLR or a stock KLR then it is another issue. There's no overboost protection in the DME III chip at all, and the rev limiter is 7K RPM. If nothing I've stated here addresses your issue I would suggest you call Dave and tell him what it's doing. If you can't get in touch with him, give me a call later today. I'm going to be out for a bit but you can leave a message and I'll get back to you.

Regards,
Russell

LFA951

I had that same problem with the LR chips, boost spooled quicker, but cut out was inevitable, I put my Autothority chips back on and problem went away...

mnmike

i did get both max chips. I emailed dave but he hasn't got back to me, ill have to call him Monday..

The DareDevil

So Russell, any news?

mnmike

also ive noticed when it happens, it sounds as if the car pops through the exhaust, does that mean its the air thats cutting out then?

mnmike

dave just shipped me another KLR chip. If this doesn't solve the problem Ill have something else to figure out..

Mach 5

I just bout a '86 951 that has the 951 Max chip set, Lindsey manual boost control, and a CAT delete exhaust. I am experiencing the exact, and I mean exact, issue as described by the OP in this thread. Cut out above 5K on max boost, usually preceded by a backfire. The 951 max chip set was acquired by the previous owner during 2012 or 2013. Just curious if anyone knows if or how to resolve this?

Also, I put the stock chip back in and it was going into the over boost protection mode over 5K max throttle. I dialed the boost back and it seems fine. I would prefer to take advantage of the 951 Max chip if I can figure out why it keeps shutting down. Any help is appreciated.

Roger

jmj951

Just curious - if you dial back the boost to 11psi max, does it still happen? I ran these chips on the track many times before converting to a MAF system, and I never experienced this, but I did not have an MBC to turn up the boost (and still had the cycling valve).

LUCKY DAVE

I has this exact same behavior when I changed from Max 951 chips to Josh's A tune.
It turned out to be an ignition coil that chose the same time to fail. It was a simple coincidence, but one that pointed me (and Josh) at KLR problems that didn't exist.
Just on a hunch I replace the coil with an MSD and the "problem" went away.

Mach 5

I just reinstalled the 951 Max Chip and reset the FQS to position 1. I didn't get a chance to test it with the lower boost yet. It was dark, wet, and foggy by the time I was ready for a test drive. Probably not the best time for a "max boost, max power" test run.

Mach 5

So this would imply that each chip puts different demands on the coil? I would think that the coil would not see anything different from the chips, but I certainly don't know.

LUCKY DAVE

A denser charge puts more load on the coil, in theory.
I have no idea if the amount of charge density change we're talking bout here is profound from the coil's point of view, I doubt it.
In my case I believe the coil just happened to fail at the same time, pure coincidence.
But the symptoms were exactly as you describe.

Mach 5

I looked at the coil last night. It looks like it could be the original. I ordered the MSD Blaster 2. Probably a good thing to replace anyway.

Roger