No boost past 11psi

[rosie]

I have lived with this on my daily driver for 2 years. If I try to Gvalve it, it leans out at 11. Map sensor right? I did a test drive with an expert (not supposed, he's the man) spouting off reading when and what (tps, map, o2, open loop, etc....) and all of it sounded normal. Except for the boost inhibiter. WOT is electrically WOT and idle tps is .9v O2 is rich at 11psi lean at 13.
I haven't messed with it for a while, just cruising, but I was always convinced I had a bad ground somewhere. Haven't found a bad one yet.
This is what has been done to the GLH related to the powertrain.

2.2 commonblock with 85 head and 89 turbo roller
88 Dodge 600 smec harness to stock body harness.
52mmTB with 1piece hogged out at the neck (to same ID as Tbody)
2.25 frontmount IC tubing...with an IC in the middle of coarse.
4 wire O2
Custom cal 2bar with no overboost or Air Charge and fan points changed.(tried 3 cars, 2 cals[same cal just reloaded], and 3 smecs) My car is the only one having issues.
2.5 downpipe to stock exhaust (shut it) for another week till my 3"bends get here.
Stock rebuilt turbo (supposed to be merkur spec but stock one sat in my closet for 3 years before I relized it was stock)
255hp walbro (in tank)

Mechanically it WILL go past 11 so it isn't the wastegate or turbo or timing. It just decides it won't give me any more fuel. No vacuum leaks, injectors/fuel rail/regulator out of a car that boost's 15psi daily fuel pressure good with/without regulator...

I am ringing out wires as we speak to find something out of place, but if anyone has any bells go off that I need to check, post, recheck... please LMK. No one has been able to help so far but that's because I didn't ask here... Right??

Thanks for any help or support.
Rosie
San Diego
87 Shelby Lancer
86 GLHt
83 Scamp GT all original... for now...

[black86glhs]

What about the injector sizes? The stock injectors might lean out under those conditions? That is what I could come up with.

[cordes]

Fuel filter?

[turbovanman²]

I would do a test of the fuel system first and if it had 2 factory fuel pumps, did you take the inline one out?

http://www.turbo-mopar.com/forums/vb...e&articleid=36


IF that checks out, have you had the ox sensor tested with a labscope and some propane?

Barring that, the only thing I can think of is your cal is bad, you mention you've changed computers but kept the same cal. Maybe try a known good one or try a stocker with a MAP bleed or diode.

[rosie]

What about the injector sizes? The stock injectors might lean out under those conditions? That is what I could come up with.

There the T2 injectors that were running 14psi in my shelby Z.

fuel filter?

I changed that with the pump. I remember because I had to replace the lines and clamps. BUT it's a fram. Never had any problems with them but I've apparently been lucky with my rods too (another post with another Steve) What FF should I put on it tomorrow? Or order tonight? It's been a year or so; I don't have a problem shotgunning that.

Sooo many wires are good. I'm going to have to print my schematics and bust out with the magic marker.

[rosie]

I found a wire with 1.4 ohms instead of .3 like the rest. Don't know if that would cause the problem but it's from the coil positive to pin 1-10 on the 60pin. It splices off to the ASD, fuel pump, O2 sensor, then to the fuel injectors for ground to back of engine. Ground itself is good (just replaced it too) and ground to 1-10 is .8 . One last thing before I go to bed. The Ground for the injectors is grounded to the rail so I'm going to re-splice it to the rear ground.

If someone shot guns it correctly, I'll send you a brand new ground (goes from the head to fire wall one)! Picture the stock one but brand new and the holes for the terminations are meant for bigger bolts (I'll send star washers too)

Rosie
P.S. Not being sarcastic (I'm known for that) I'm offering up 1 make that 2 now, brand new grounds straps and I'll make the second 1 a 12" long one if you want (those are the 2 sizes I have). I'll pay shipping and everything! If I find it before you... no prize. Or maybe I'll trade you a couple for a good fuel filter!

[cordes]

Do you have a way to verify the FP while you are driving?

[rosie]

Do you have a way to verify the FP while you are driving?

Yea. Fuel pressure went up 1psi with every psi of boost. Took off the top grill and ran gauge through there.

[cordes]

If you are getting good FP, then I would think it can really only be the injectors. Are you sure they are getting a good signal?

[rosie]

Not positive. The only way I know to check them is with the resistance of the wires going there. I checked the fuel injector harness seperatly, then I checked the enging harness going to the injector harness. Then I started checking grounds from all the systems and computer. Haven't found a bad one, just that little bit higher 1.4 ohm one. I brought home my daisy chain of grounds and will replace/recheck that, then the try the fuel pump check. On a shotgun note, I just ordered a new one but if this one is good I'll put it in my Lancer.

[rosie]

Just ran a bunch of extra ground straps to some area's I felt might be lacking. I have to get one more grounding the engine to the body (near the passenger side Motor mount) with something better then that clip on ground strap.

BUT. I did get the ohm's down to around .9 . It went as low as .7 but it still isn't .3 like everyother wire I've ring'd out. I'm going to dive into the mess of wires known as location 1[Z1] and 2[Z1] where they all splice together before off to 1-10 at the 60 pin.

Posting so you're all posted on the shotgun repair contest!

Still need a camera but I'll try to get pictures of my Gstraps and where I put them.

[rosie]

After finnally decoding where 1Z1 actually is (1Z2is that double ground at the fuel injector harness) I started getting ADD and shortening my wiring harness. Never trimmed it down when it went in the omni or pulled out the optional head light sensing peices of the harness so I could have less of a mess to weed through while getting to this higher ohm'd wire. The good news is I know where to start looking.... it's the bulkhead plug. can't friggen wait to open that big can of worms. Not scared of the electrical diaging, just that little cubby hole is TIGHT and I never trimmed those wires either!!

I'll update more tomorrow. On that note as this has become a blog, has anyone read what circuit I'm talking about and made a possible paper diagnosis? I know I'll be an expert on this circuit when I'm done!

[2.216VTurbo]

Well, at least you're not having to work on the bulkhead plug underhood on a teeny little L body I can't imagine your big meathook hands are gonna fit well back there

[rosie]

Yea, and I'm worried if I pull on it too hard the car might flip on top of me!

[black86glhs]

The bulkhead is easy. Going under the dash, that sucks.

[rosie]

Where are the diagrams for the fusible links. I have one that splits from ....

Orange to 2 wires. One 18 gauge blk and one 16 blk/rd. The blk goes to .... nowhere! and the blk red goes to 35 on the bulkhead. Diagram says electric window heater but I put it there because of the black red and gauge side. I think the other one went origanaly to the wiper motor but I never hooked that stuff up.

So, on a split fusable link, are they both power ?

[rosie]

Never mind. I'm getting tired. Like my multi meter disappeared and I forgot how to check where a wire went.

Sorry for the panic, you can cancel your flight to san diego.

A black power wire.... Jeez. I'm looking for a red ground now.

[rosie]

Never mind. I'm getting tired. Like my multi meter disappeared and I forgot how to check where a wire went.

Sorry for the panic, you can cancel your flight to san diego.

A black power wire.... Jeez. I'm looking for a red ground now.

It is (drum roll please).. <drum roll not a punch line!
The power wire to the under hood light. Wow, wonder if THAT was my boost problem.

I just got rid of a bunch of wires for the cruise control, fuel signal (trip computer) and some other stuff. Still a mess but oddly enough, I didn't actualy DO anything but that ground came back into spec. Maybe something wasn't sitting just right in that rats nest and when I moved it around it got comfortable. I also found an unrelated ground that I couldn't find in any of the schematics. Found where it should be if the wires matched the print but one went to ground so I grounded the other one that was a "spliced" wire. I did this after I had checked the other circuit so that wasn't my eureka moment.

I'm not confident tomorrows test drive will yeild 15 psi but we'll see. At least I got past the wires, for now. I still need to shorten them. Next is fuel checkin time, and the circuit that goes to it... Oh yea, and a scavenging trip to the yard for injectors and TB sensors.

[rosie]

Solid 12 then my TPS started acting up again. New development with that is that I've never gotten a code (24) for the tps rubbed out resistor thing and every time my car bumped(this problem came way later then the no boost thing and I swapped in 3 TPSes) the check engine light would come on. I thought it was the knock light (I have one of dem) because there was never any codes. I came to the rubbed out resistor diag after reading another thread (derr, never would have thought of that) so I was going to get another anyway. And now that I have cleared up my harness wires (continuity, not length) I'm getting that code.

At least I helped something. No issues with the TPS in any range other then accel from stop and cruising, classic heavy use area's that's sure to go away with a new one. Now I can't find my TPS stock! What kind of T-M nut am I?

Going back to the fuel system tomorrow. Getting some 2.5 injectors (for spares if it IS them) and a fuel pump is on the way (chris I'll send you a money order monday) But in unrelated news, it's off to the shade tree fabricator for a 3 inch exhaust. Maybe THAT will fix everything!

Thanks for your help guys
Rosie

[2.216VTurbo]

Uh, I know where your spare TPS's are, they're in your pile of spare throttle bodies Same place I keep mine