I have a 87 t2, all stock except for a 2.5" downpipe
I do 5psi in 2nd until around 6000 when it drops down to 4psi and at 6500 I have been hitting a brickwall. Its just like all power shuts off. I mean its still boosting and this has never happened before and literally scares the crap out of me
I boost about 6.5psi in higher gear so its not the ECU fuel cut.

I have a new fuel filter, but someone suggested the sock filter on the pump in the tank. But its at 6500rpm almost exact and only in 2nd gear that Ive experienced it. I have no idea what could cause this to happen.
My plugs and wires are original from when I bought the car and I have been thinking a lot about changing those out in two days when I get paid, or at least the plugs to start with.

Any ideas or anyone ever experienced this?
Any help is greatly appreciated
Thanks,
Ben "Laden" Martin

 

hit 6500+ in 3rd without it happening?

 

Plugs would help. I changed them and saw improvement. Should you check your wastegate?

 

erm, havent really checked in 3rd. the wastegate is not a problem. my boost gauge SHOWS it drop from 5 at about 6000 and go to 4psi when it happens at 6500
im gonna go buy some plugs today and change those out and ill check 3rd gear and report back. hopefully I dont get pulled over doing my 90mph test run

 

TPS out of range...

 

You sure it's TPS? At 6500 I doubt he's still in the narrow TPS range any more. It should be seeing WOT.

 

If the TPS is reading over 5.5k-ohms @ WOT, the car will cut out and the TPS will need to be replaced.

 

hmm, thats pretty interesting.
how would I go about checking the TPS for this cutout?

And btw that whole time the throttle was WOT for about a gear and a half before it cutout so shouldnt TPS be reading the same thing? Maybe its a combination of electrical problems working together to **** me off

 

My check engine light comes on around 6500 rpms in 2nd-3rd gear. Code is 12 and 18, narrow and full range tps. Reads at 7.5 or something ohms on full. So yes, check engine light comes on and the car goes into limp mode, is this what you're experiencing? I was told to replace the TPS... working on that now.

 

Doh! of course! Just because the TPS is narrow doesn't mean it's no longer getting read. It just means it's reached it's max output.

Node.

You can test the TPS with an ohm meter or volt meter.

Just swing the throttle to WOT and see at what ohms the TPS tops out at.

I think stock range is up to 4k + or - 1k ohms.

 

Factory fuel cut off switch? I know when I installed a down pipe on my stock t2 the boost increased enough to require a bypass. 100 bucks from racing beat or there are ways to do it yourself. If this is the case, I would take it easy because obviously high boost and no fuel = major problem.