My PMO ITB Project

[MrPerkles]

Well done Trog, very interested in your initial driving thoughts.
Still cant get mine to work but I think ive now found the problem so back to the shed tonight

[onboost]

Originally Posted by juicersr

Paul, I just installed the TecGt in the turbo and am very pleased. Very tunable and user friendly, and I believe cheaper than the 3r. IIRC, clewett said the 3r was better for twin plug application. Electro seems well past the issues that gave them a bad rap in past.

Troy, congrats!

Trog, & Juicersr, Thanks for the input from both of you, I've been considering & looking at several systems including the TECgt which comes in at a very decent price point.

Guess I better look a little closer as you mentioned one, or some, may work better with twin plug and that's what I have.

Good luck to both of you with your tuning and dial in!!

Paul

[Trog]

My synchrometer is scheduled to arrive this weekend. So after a little balancing and tuning, I'll take her out for it's first spin.

I'll post a vid to You-Tube once I figure out how to use my camera.

[Trog]

I should report that I’ve experienced a rather odd electrical problem with this ITB upgrade. Although the engine starts up easily, it won’t stop. There are many Pelican threads on this subject, with different solutions. In my case, when I turned off the ignition, the “BATT” warning light illuminates and the TECgt and its associated fuel relay remained powered. Seems the alternator was back-feeding through the “BATT” warning light.

The Bentley manual shows a diode in the circuit to prevent this backflow. The Haynes wiring diagram states that in 1984, only the Turbo model has the diode. I searched for it, but couldn’t find it.

In any case, I installed a #1N5820 diode as shown below, now the engine shuts off without any hesitation. If you’ve experienced a problem similar to mine, this may be your solution.

Now, back to my tuning efforts.

[toddu]

Not to change the subject, but I'm wondering what hose clamps you're using on the heater hose? Is that a type of t-bar clamp?

Todd

[MrPerkles]

ive got exactly the opposite prblem Trog my fuel pump relay keeps shutting off and the srter motor wont engage getting fed up now.
When you going for your first blast up the road ?

[Trog]

Originally Posted by toddu

Not to change the subject, but I'm wondering what hose clamps you're using on the heater hose? Is that a type of t-bar clamp?

Todd

I used "T-bolt" hose clamps.

[Trog]

Originally Posted by MrPerkles

ive got exactly the opposite problem Trog my fuel pump relay keeps shutting off and the srter motor wont engage getting fed up now.
When you going for your first blast up the road ?

My TECgt runs the fuel pump for a few seconds, then it shuts off unless you try to start the engine. I'm thinking it's to avoid running the fuel pump continuously if you left the ignition in RUN, or if the engine has stalled.

Could be you've wired the TEC up to the wrong relay?

T...

[Trog]

Originally Posted by MrPerkles

When you going for your first blast up the road ?

Tomorrow, providing I can set my idle mixture correctly. Running much too rich now.

T...

[Jeff Alton]

Originally Posted by Trog

My TECgt runs the fuel pump for a few seconds, then it shuts off unless you try to start the engine. I'm thinking it's to avoid running the fuel pump continuously if you left the ignition in RUN, or if the engine has stalled.

Could be you've wired the TEC up to the wrong relay?

T...

My microtech does the same, runs the pump for 15 secs then shuts off if it does not get a signal from the toothed wheel on the crank.

Cheers

[MrPerkles]

I have put a new relay and wiring in for the fuel pump,but the shut off condition has got me thinking ,good info guys thanks a lot

[TimT]

I'm thinking it's to avoid running the fuel pump continuously if you left the ignition in RUN, or if the engine has stalled.

This is correct, when you switch the key on, the fuel pump pressurizes the fuel system. If you dont turn the key the rest of the way the fuel pump shuts off after a bit. As soon as you start cranking the engine, and the ECU sees a crank signal, the fuel pump switches on again.

[MrPerkles]

my fuel pump relay almost instantly trips,any check list for this ? maybe battery not holding enough juice ?

[Trog]

Originally Posted by MrPerkles

my fuel pump relay almost instantly trips,any check list for this ? maybe battery not holding enough juice ?

You need to isolate the problem. First, we need to verify if the fuel pump relay picks up and stays energized when isolated from the TEC. The relay gets its power from your switched ignition source. First, with your DVM, make sure that this power source stays 'Hot' in the RUN and START positions. It's important that the power does not drop-out when the ignition switch is in transition between these two positions.

Once you've confirmed that the 12VDC remains on, then remove the connection between the fuel relay and the TEC. Ground this wire and see if the fuel pump relay energizes, and stays energized. If this tests OK, then the problem is at the TEC. If the relay drops out, then the problem is with the vehicle wiring.

Report, and we'll take it from there.

T...

[Trog]

Getting the throttle linkage just right took a while. It’s important that the throttle pedal reaches its end of travel before the ITB hits its travel stop. I suppose every application is different, so all I can do is describe what I needed to do. First, the top of the hole in the rear tin where the throttle linkage penetrates the engine bay had to be elongated. I removed about 3/16” with a file. Ideally, this should be done on the bench while you’re installing the cam sensor. That way you get to avoid the rather uncomfortable yoga position I had to assume to reach the area. The long throttle linkage under the vehicle is adjustable for length. Loosen the lock nut. Then, select the appropriate locations for the ball-socket (not sure what the proper term is). Again, your application may vary, but the following photo illustrates my arrangement. The PMO and Clewett website offers instructions on how to set-up the various linkages. Once you get started, it become fairly obvious what the objectives are. The PMO throttle return springs are supposed to clip onto the bottom of the air filters. As I’m going with a different air filter arrangement, I elected to place a large return spring between the bell-crank and the linkage mounting plate. Note; I went through a half-dozen springs before I found the right length and tension.




With the linkage sorted, the next step was to balance the ITB’s. Start the engine, let it warm up and when at idle, use your synchromoter or manometer to balance the airflow using the ITB needle valves. Then set your RPM to 3000, and check each ITB flows again for linearity. If you’re lucky, then each ITB will flow the same at idle and at 3000 RPM. If it’s off, then you’ve got some adjusting to do.



Now it’s time to hook-up the laptop and play with the tune. I need to lean out the fuel mixture before I asphyxiate myself.

Stay tuned...

[Trog]

It won’t win any Academy awards, but here’s my vid:

[village idiot]

Tuning or not , it sounds great! Throttle response seems very good too

[MrPerkles]

great vid and neat install ,how tempting is it to run without airfilters and show of those lovely trumpets

[Trog]

Originally Posted by MrPerkles

great vid and neat install ,how tempting is it to run without airfilters and show of those lovely trumpets

The temptation is overwhelming. So I've purchased a little insurance:




http://www.pegasusautoracing.com/productdetails.asp?RecID=6250

[dfink]

Did you use an idle air control valve, if so which one and how did you plumb it.