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Holley TBI Install problems

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bigcat44

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So I purchased a Hollet 670 TBI unit here and started the install. First problem I noticed last week was that I needed an adaptor plate so the bigger bores would work with the smaller bores of my Edelbrock Performer manifold. I got the new adaptor and new dust caps with wiring. Next problem I noticed yesterday was that the wiring for it actuall has a clip that I don't have the other end to, my TBI was wired right in? Question: Can anyone tell me what actually comes in the brand new TBI kit from Holley? I got everything bolted in but now it's idling at 1800 with the idle screw completely backed off. I know I am having a vacuum leak and I think it's coming from 2 holes in the plate that I didn't put plugs into, the next thing I noticed is that it is dumping a ton of fuel from the injectors, enough that it is splashing out while idling. I am beyond frustrated with this, has anyone installed or at least ordered one of these TBI units before? I need to know what I am missing here, I am thinking that Clip goes to a wiring harness that has a seperate brain box or something? :confused:
 
Just an FYI, you are going to have alot of problems with that TBI, unless you have a high hp motor. If your motor is stock, or close to stocks, then you need to switch out those injectors with stock injectors. You basiclly bolted a 454 TBI on. To much fuel for a stock 350 or even a mild 350. I ran a stock TBI on my old burb, and was getting close to 375 hp out of the motor.

Dan
 
Thanks for all the help. I went and pulled the TBI and plugged the ports, I also noticed the bottom gasket on the manifold was not seated correctly so I reseated that and then I adjusted the Fuel press regulator. After starting the engine, no leaks, no vacuum leaks and the idle was just a little low so i adjusted the idle screw and everything is working supreme!! It still has a slight fuel splash at idle but nothing I was too concerned about and I see what you mean by it running rich. The Injectors work great after I adjusted the fuel press reg, it was maxxed so I backed it off 1.5 turns (I am not running a psi gauge there yet) and that settled them down quite a bit! Thanks again for all the advice, let me know if I should be looking at anything else.
Lee
 
No with the fuel plates or buttefly valves in the idle or slightly open fuel from the injectors is hitting the plates and a little splash is coming out, not really much at all now since I turned down the F press Reg but before it was with alot of pressure!! Now anything if at all that is splashing is caught on my airfilter plate so I am not worried. Injectors are great, no leaks, gasket is great no leaks and no vacuum problems thankfully! I found I have a coolant leak on that hose that is half rubber then connects with a swedge fitting to a metal tube. The hose runs from the heater core to the back of the intake manifold and it's the metal part that has the hole. Called Auto Zone and they list it as dealer only item so I'll call tomorrow.
 
hose fix easy. take quick coupler out put barb fitting in from older truck style and remove hose and replace with reg hose and 2 clamps and done. but make sure you take your time with the old fitting as thay tend to brake easy.
 
There is some good information in the above replies, and some not so good. To save a BUNCH of typing and band width, to a search. I went thru the same problems when I put my 670 on, and if you do a search on my username, you can read the whole sorted story. Basically what's happeneing is that Holley used Delphi injectors (and no they will NOT interchange with the stock injectors BTDT) which flow a LOT more fuel that the stock injectors. Meanwhile, the computer still thinks you have the stock TBI on, and is still telling the injectors to fire for the same length of time as the stock injectors. The reslut is a lot more fuel being dumped down the bores. Additionally, the throttle bores are about 20% larger so they are allowing more air to pass by them at idle setting resulting in a higher idle speed. I'll also bet during the cold start cycle, you are getting clouds of black smoke pouring out of the exhaust (VERY rich condition) along with a looud popping in the pipes as the exhause comes up to temp. The only cure is to reprogram the computer chip or have somebody reprogram it for you. Brian over at TBIchips.com can get you in the ball park using the .bin he made for me, but ultimatly, you will have to learn how to do the final tweaks yourself. Agan, do a serach for my user name and read what I went through, then if you have any questions, don't hesitate to let me know. :grin:
 
Thanks for the info, FYI, the above info is AFTER scrolling through almost 20 pages of searched material!! I have the idle down now and no black smoke, also the injectors on this unit are not the stock injectors that came with the Holley, they are from Holley but were changed by the previous owner. The truck is running superb now, I just have to change the coolant hose and I'll be back driving it like crazy. I read about the chip and that is something I will ultimately do but not right now as I am not getting the same conditions you were. I am not sure what the previous owner of my rig or the unit did in terms of tweeking the fuel mapping but I like where I am at now. I bought this unit off another member here AZ88? So maybe some other members here would know more about my part from him? Thanks for the chip info, once I complete my move to San Antonio I will definately look into that.
Lee
 
speaking of bad advice you don't need to remap your fuel curve because you put the holley tbi on....


I'd suggest getting a psi gauge and a regulator(think you said you got one) and play with that and the idle screw to get the right balance between good idle and good topend. Also Make sure the plate that holds the injectors in place is tight. if it comes loose or wasn't tight it will DUMP fuel in your motor out the top of the injectors. Basically if the plate is loose, instead of atomized fuel you'll have drops.
 
Dw,

Not trying to start a wizzing match :grin: but adjusting the fuel pressure is like putting a band-aid on the real problem. Believe me I tried. When I would back the pressure down enough it lean out the idle, I was increadible lean in the upper rpm range. Increase the pressure enough to feed higher rpms and I went rich at idle and lower rpms. Yes, you can find a balance, but it's a fine line and easily knocked out of kilter. The proper way is to shorten the base pulse width and make changes to the CL/AFR and OL/AFR along with the CL/AFR vs TEMP and choke delay.

In other news, :grin: I'll be getting me Prominator in a few weeks, so I can really start screwing things up instead of having to send datalogs to somebody and hope they get it right. :grin:
 
Dude, I agree that shortening the injector pulse is the BEST way to do it but it will cost you 500 bucks. I am getting a prominator because of the other mods. A stock motor with nothing but say headers and the holley tbi will be fine with some tweaking. Holley says your psi should be at 9 psi IIRC with the 670 cfm tbi. As long as you can get it to run good up top and still be able to play with the idle screw you should be fine with the stock pump...

i have a 45 psi accel pump with the 670 cfm tbi and (when i don't have a vacuum leak) it idles good and revs fast but since its been raining over here i don't have the rest of the stuff hooked up to give it a test run.

The holley tbi comes with an adjustable regulator in it... but its a PITA to take it out, adjust, put it back in, and do it over and over until you get it right.

He said he got it to run good with a regulator tho so no worries.
 
Dw,

I'm glad that we can agree to disagree on some points :grin: For some reason, I just couldn't find a happy medium with fuel pressure alone, so I had to go the re-map route. My 88 is also bone stock ('cept for that 670) and I had a LOT of problems getting it to run right until I had the fuel curve leaned out. BTW, I'm pretty sure you are right on the pressure, 9-14 psi sounds very familiar.

As far as the $500 figure, I can't get that one to add up, unless you don't have a PC. The prominator costs around $200 and all the software is free, or at a very reasonable cost ($35 for the good version of tunerpro).

I guess in the end, if you can get it right with the pressure regulator, yer good to go. Also, he mentioned that the PO had changed the injectors, so that probably why he a pretty easy time getting it sorted out. :grin:
 
So Bigcat, Did you notice a big difference over the stock TBI? What have you done to your motor? I have a bigger cam, balanced rotating assy, Edelbrock Performer manifold, Doug Thorley Tri Y headers and I was wondering if you think the 670 will beneficial for me? Thanks
 
I can definately feel a seat of the pants difference, throttle response is great and the idle is a bit smoother. I have not driven enough to see mpg effects but I did some quick short runs just messing around and the Jimmy gets up and moves. My only mods so far are Edelbrock manifold, Open air element, Hooker comp long tube headers and Flowmaster 40 series true dual exhausts. Thanks for all the great advice in this thread, I will eventually get re-mapped but I would like to do a few more mods and then remap plus with the upcoming move I haven't been able to do too much to the rig.
 
I forgot there are 2 prominators.... one is 200 or somethin close to that and the other is 275. the one that cost 275 has the ability to store 6 maps which you can change with the switch that you have to buy for extra IIRC. It also allows you to tune on the fly without sending the ecm into "limp" mode. the cheaper prominator does not have those abilities.

The computer your using to tune your ecm will need to be a labtop if you want to get it right.... sure you can rev it up in your driveway but the A/f ratio will surely be different with a load. Thats why you need a labtop. Unless you just want to change the idle you need to log a map while under acceleration and then modify it.

labtop= 100
prominator= 300 (shipping and you have to send your ecm to get it soldered in unless you have a c4 ecm)
tunerpro=35

OK not quite 500 but 435 bucks is still a good chunk of cash.

Good luck with your prominator. Post up the results and what you think of it when you get it. There is still a lot i would like to know about it.

Mtrdrms... the holley tbi was made for motors just like yours. It will support 275 hp without tuning and up around 350+ hp with tuning and fuel pressure mods. I second the throttle response statement. There was a HUGE difference between my old stock motor tbi and the new tbi but my new motor has a lot of other mods on it besides the tbi.
 
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