TOPIC: TBI Testing and Information

Welcome to the forums, Bimmster! I hope I may call you James.
Tracy (Sgt Schultz) Gallaway of Reno NV has been doing a bunch of these lately if memory serves. He'd be the guy I'd suggest you get on the case, unless you're interested in picking up the bit yourself, like Joshua has.
If you scroll down to the bottom of the Gadgetman home page, there is contact info for him in the right hand corner.

Hi Bimmster, you've found us!

I'll say just a little here, then give my contact info to get you started.

My journey here began 5 years ago, and I've been richly rewarded for it. I've made new friends, learned a LOT, and learned the value of sharing ideas and knowledge with others. I met Ron Hatton and trained with him in person. Seen and learned to apply this amazingly effective stroke of Genius.

You can join the Adventure. We have a lot to share re: GM TBI systems, one of our faves! While there may not be any active Gadgetmen in your area, we'v put together a package for new folks like yourself. You can learn this technology and take advantage of what we've discovered over the years. And get better results faster than anyone (well, most anyone!) could 5 years ago.

Contact me: This email address is being protected from spambots. You need JavaScript enabled to view it. 775 544-7692

Tracy G

Hey James.

Unfortunately, 99% of the people we have in the network are mostly wallflowers, and unworthy of any recommendation of mine to do any business with them.

That being said, we have a couple of options for you through our mail-in modification program.

1) You can send us yours (requires about two weeks downtime).
2) You can order a replacement throttle (with our assistance-PREFERRED) and have us do the mod for you. (we can facilitate that as well)
3) You can learn to do The Groove through our Personal License Program.

The latter (Personal License Program) is probably the best option of all, because for the same price ($500) you can learn a new technology, and have the ability (AND the permissions) to modify ALL of your gasoline equipment.

We have just instituted a Scholarship program for selected applicants. Just contact Tracy (Gadgetman Reno) at This email address is being protected from spambots. You need JavaScript enabled to view it. and ask him about it if you're interested in any of these.

(Canadian modifications are managed by Greg Kusiak (heysounddude and our Gadgetman Ontario) at This email address is being protected from spambots. You need JavaScript enabled to view it..)

No matter which way you go, you will be absolutely THRILLED with the way your vehicle responds. It is fairly common in those GM TBI systems to see double your mileage, with attendant improvements in power delivery, temperature management and emissions.

One I did actually went for 6.25 to over 36 mpg's!

THAT is Sa-WEET!

No matter what you do, be sure to come back here and let everyone know what you find here in Gadgetman land!

And if I can be of service, you have only to reach out your hand...

Ron
Gadgetman

Alright Last night i went home after work and climbed back into my Tbi haha!

So i did what Ron said removed the TBI spacer and checked and cleaned my IAC valve check the wires made sure it was operating and its good the next thing i could do is go to the dealer ship and get a new one and a new o2 sensor the o2 sensor on it now is fairly new but its from auto-zone.

I also did what heysoundude suggested and opened up my IAC pathway in the epoxy by making it a little wider and deeper sorry forgot to take pics of that also did get the idle adjustment screw back to it original set point

Quick question why when i pull the number one spark plug wire off my engine doesn't change idle it stays running like nothing any idea? And it is sending spark i know Because it bit me when i went to put the wire back on the spark plug haha

So i reinstalled the Tbi with out the spacer just the adapter and it idles at about 700rpm in park in gear it drops to about 400rpm i still have to put my foot on the pedal to get it to start and keep it on until it warms up to operating temp went for a little ride it seems like it wants to turn off when i come to a stop the exhaust is still pretty stinky so i know its not right just yet.


I got Pics of the adaptor, spacer, tbi while its all together where i rerouted my PVC hose


This is the adapter its 1/2 thick


This is the only bad thing i could figure the is messing up the the air stream for the groove


The hose at the top of this pic it running to my brake booster


The Spacer is 1" thick


I had a friend at work drill out the spacer for me in the past to be the same size as the throttle body bore for better air flow




This is with all three of them mounted i did check every time for leaks never found any
Yes i did grind down all the Air dams around the Bores


Looking into the TBI wide open throttle

Some more Pics i can only do 8 at a time sorry

Thanks Joshua Padilla



IAC valve before i cleaned it


Driver side TBI bore opened full Throttle


Passenger side TBI bore opened full Throttle



The fitting in the air cleaner is where my PVC hose is hooked up


Excuse the messy under side this is where i rerouted my PVC hose to on my air cleaner

Stinky exhaust - is it hot and moist? The smell will go away as the water vapour cleans out all the deposits from your engine and exhaust system. Think of all the crud in there from over the years...

Yes, if you have to keep gassing the engine to keep it running at idle, it's not getting proper air. A new IAC valve should fix that...when you're in at the dealership picking it up, ask what it should idle at. (Or you might be able to look it up online...) 400 is probably too low, but not by too much, and 700 is probably high, but not too high. See if you can split the difference and get 550ish- that's probably not too far off the factory spac. (I'm talking the green ring around the bullseye here)

How much over stock have you gapped the plugs? If it's not misfiring with one of them out - and badly!- they can probably get opened up more... .060" or more even...(this can adjust the idle due to timing...)

You're closer than you think...keep going!!

Alright sounds good will do the plugs right now are .050 i will gap more this weekend
Thank You
Joshua Padilla

Josh,

I made a video on spark plug adjustment that is here:



While this lawn mower went from .028-.032" to an amazing .105", there was more this system had. (I got tired of gapping then filming then gapping then filming the gapping...)

Watch the video and THEN approach your plug adjustment. FAR better to do the whole job the first time.

To break it down to a simple process, it is take one plug, ground and regap that one to its fullest. Then take your final setting and use that on the rest of your plugs. If your efficiency drops, then you've gone a tad too far.

Reduce the gap by .005" on all your plugs. That oughtta do it!

Have fun!!!

Ron
Gadgetman

There should be a sticker in the engine bay that tells you what stock gap is. Take that number and add 25%, then creep it up until mileage/power/driveabikity takes a hit and then back it off. There is a sweet spot when everything is just "right".
I did this with my old truck and found about 40% over stock was ideal.
Ron made a great video to demonstrate using a lawn tractor. Look on YouTube.
When you get there, make sure to do a full ECU re-learn drive cycle to hammer it into the computer. Then report back on your gains please.

Hi Joshua, everything I see here looks OK to me. I see no obstructions in the airflow path thru the TBI throttle body and spacers. And, all your work is clean. I did wrinkle my nose slightly at the brake booster hose. Long as it is sealing Ok, then Ok. The factory used a thick wall hose, this looks like a replacement one. With the age of it, you should use a mityvac vacuum tester. Pull that hose off the manifold fitting and use as many pumps on the Mityvac as it takes to pull a vacuum on the hose (20 inches hg.or more) and brake booster. Then watch the gauge, it needs to hold as long as you can stand to watch it!

The IAC and IAC epoxy trench- Start it w/ cold engine, check to see that the RPM's start out higher, and go down as it warms up. That verifies the IAC valve is OK. Then can get to details of what speeds the RPM's are.

I'd advise checking the cap, rotor and plug wires, check the Ohms resistance of the wires. Timing- what's initial advance on the dist. at now? Is the vacuum pod and advance mech. OK? Late timing and/or any ignition issues can reduce idle RPM. I always go top shelf for all ignition parts. Battery condition and charging system OK? Does it always fire right up easily every time? Any hesitation or lag in throttle response? Does it always idle and run smoothly?

With a distributor based ignition, even GM HEI, it needs more attention to detail than the newer dist.-less ignitions. IF the HEI dist. is the original, it could need maintenance. Just a possible reason for the low idle RPM's, lack of change when ya pulled that plug wire.

This is all the kind of stuff I'm talking of in the Instruction Sheet I sent ya. It all adds up!

Great pics, Joshua!

Tracy G

I was just over to to see which posts I had and found I needed to put one there on regapping your plugs, so I did.

Start with the first post, though and read all the way through Post 9: Regapping your plugs .

Ron

Re: Your #1 plug.

what you have there, my friend, is a not-at-all uncommon malady of older engines. You have a dead cylinder.

This is most usually caused by a burnt valve, but can also be caused by damaged rings (fairly rare), a blown head gasket or a bad or fouled spark plug.

What this calls for is a compression test. I recommend one across all cylinders while you're doing it. You will probably find (98% sure) lost compression in that cylinder. If so, it can either come from the top of the cylinder (the head-most likely) or from the bottom (rings).

Be sure to write down ALL values for comparison. If #3 (the bordering cylinder) shows substantial loss, you probably have a bad gasket.

If the value drops substantially and solitary, you certainly have a bad cylinder seal as mentioned above. In this event, you will run the test, then drop or spray a lubricant into the cylinder and test again. If the pressure goes up, you're looking at a bad piston seal and will be needing a rebuild.

If, on the other hand, there is no significant increase in pressure, you need to do a head job, as the problem is either in the gasket or the valve seat.

I suspect a burnt valve, but that's just a guess...

In EITHER of these events, you have lost cylinder integrity. This will cause a SUBSTANTIAL drop in intake integrity and will defeat much of the effects of The Groove.

Sorry to be the bearer of bad news, but at least it's probably NOT deep-engine!

Have fun and let me know if you need any emotional support...

Ron