Looking For Help With A Merkur. Stalls When Accelerating.

[NickGarrison]

My brother used to come to this site often so I figured I might try and see if I can get some help here as most Merkur sites have very little traffic.

I have an '87 Merkur XR4Ti. Basically the same drivetrain (turbo 2.3l) as the SVO's and turbo coupes.

The car idles fine and runs great. Only when I start making boost do I have issues. I can get to about 13-15lbs and it will stutter and stall every time.

I'm sure it could be any number of issues but maybe someone on here has had a very similar issue as well and can give some insight.

Thanks

 

[MY 85 GT]

Waste gate closing?...yrs ago we used to use the vice grip trick to hold the gate open to make more boost...or hold more boost i forget..lol I had like 5 turbo coupes and a few Merkurs...

Also what are you using to make it make more boost.if i remember right they only made like 10 psi stock form...

 

[madspeed]

Any computer codes?

 

[NickGarrison]

Has a garrett t3/t4 and a porsche 944 interooler.
It's not throwing any codes.

I'm not entirely sure on the wastegate. It is the stock one.
How can I make sure it's working properly?

 

[madspeed]

Im not that rehearsed with those cars, but how is the boost controlled? Is there any type of fuel cut programned in to the ecu? My old MR2 turbo had a safety programmed in by the factory that needed bypassed when i put on a larger turbo and upped the boost.

 

[madspeed]

Also, could be spark blowout. Whats the rest of the setup?

 

[85SVOGUY]

Is your knock sensor plugged in? Disconnect it and try a run. Also you can try to disconnect the boost solenoid and run a ball and spring type boost controller

Also check your vam turbo hose. It could be collapsing under boost. That's the hoses connected to the boost solenoid on the passenger fender

 

[NickGarrison]

Don't think the spark is blowing out. I've tried different plugs and it runs the same.
When it stalls, it feels like it is misfiring. Sometimes if I gradually accelerate, I can get into the area of it misfiring without it shutting off. Usually when it stalls it will back fire.
My brother is convinced it is fuel related.
Fuel Pressure is 38 at idle.
Fuel filter is brand new.
Walbro 255 lph fuel pump

Whole set up motor wise,
K&N cold air intake
SVO 3" VAM
Garret t3/t4
Porsche 944 intercooler
Water Meth kit (currently not hooked up)
polished crank
TRW forged pistons
head ported and polished
adjustable cam timing pulley
Bo-Port roller cam
42lb injectors
3" exhaust
"high flow" cat
some sort of glass pack
TwEECer RT (my guess to why it's not giving check engine light?)

I just recently got a deal on this car and this is the only mechanical issue.

 

[madspeed]

ok, you have the tweecer. do you have an afr gauge? Are you able to datalog with your seup?

 

[NickGarrison]

I do not have an afr gauge. I believe the tweecer can show air fuel ratio though. And yes I can datalog.

 

[madspeed]

Grab a few datalogs with as many parameters as youre able to. I'll at least look at em. Ive tinkered around with my turbo fox a little bit

 

[NickGarrison]

Awesome! I'll see what I can do tomorrow morning.

 

[NickGarrison]

So I tried data logging but it doesn't seem to be working. Not really sure why. I'm connected to the tweecer and it can read and write but it won't datalog.

Also, I adjusted the manual boost controller out quite a lot and I was able to get one pull all the way through 2nd gear with no issue. Other than that one instance, it's acting the same.

 

[NickGarrison]

IT WORKS!
Basically it's been trying to run on a stock tune.
I found a tune on my selector knob and it runs great!
I always figured it would be something as simple and obvious as this.
Thanks everyone for all of your help