Looking For Info

[bobby v]

So my truck is a 90 454SS, don't know exactly what has been done to the motor except it has obviously been decked because the ID boss is blank, no numbers, its a Gen 5 and sounds like it has a small cam, has Edelbrock 1 7/8" shorty headers, not much left of the smog equipment, that's bout all I know.
So my question or objective in the future is to get some Aluminum heads, intake and Holley or Edlebrock Carb, dump this TBI.
I don't want any thing outrageous, just a nice pickup in power and reliability.
So any recommendations guys, oh, and lets not break the bank with like say AFR heads, way too pricey of this ole boy
Thanks
Bobby V

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[PlayingWithTBI]

I'd keep the TBI and ECM or go with EBL Flash-2 then you can tune yourself. Ain't nothin cheap anymore.

https://www.dynamicefi.com/EBL_Flash.php

 

[Schurkey]

You're dumping TBI for a cheap carb, and you want BETTER reliability?

 

[bobby v]

Thanks guys, I guess Im just frustrated with this damn unit. Ever since Ive had the truck it has idled high. Im not an expert by any means but I thought with the internet and forums I might work this out. So I delved into it, replaced the MAP, IACV, TPS, new plugs, new air cleaner, new fuel filter, I even found the little idle adjustment hidden screw. I have the TPS set at recommended V reading. Its idles fine in the garage, so I thought I had it worked out, right around 750 rpms but just now we went out for lunch & driving around and the idle is back up to over 1000 rpms, maybe a little lower. And the hesitation after it shifts is back also.
So this is why Im crying about it, thought I had corrected everything but nope, no dice.
I live in a small rural town and so far I have not found a good mechanic that knows these units, so I's sort of stuck, hence the desire to rid myself of this ting and goback to a carb, smart thing to do how the hell would I know but I'm at a stand still for now
Thanks
Bobby V

 

[Gramps]

sounds like a vacuum leak to me. Base gasket on tbi unit? Bad brake booster, have you checked the egr valve etc

 

[bobby v]

Yes sir Gramps I did with a can or carb cleaner, found a little one that has been corrected. My last hope for 2 morrow is the coolant sensor which I will change out but Im having my doubts that is the prob
Bobby V

 

[evilunclegrimace]

Have you checked for codes? Is the timing set correctly? Did you perform a Minimum air idle rate? Did you check your fuel pressure both at idle AND while driving? Do you have a contaminated O2 sensor? Is your alternator output correct? Have you hooked a scanner to the truck and checked to see if it is running lean ( Block learn will be over 138) or running rich (block learn under 118)

 

[bobby v]

Don't know how to do a lot of what you asked, fuel pressure was checked at 10+ lbs I was told and timing also ??? Like I said I'm no mechanic just trying to learn so that I can save a little cash but I'm all thru repacing Engine Management pieces, now don't know what to do except pay a mechanic
Bobby V

 

[evilunclegrimace]

Don't know how to do a lot of what you asked, fuel pressure was checked at 10+ lbs I was told and timing also ??? Like I said I'm no mechanic just trying to learn so that I can save a little cash but I'm all thru repacing Engine Management pieces, now don't know what to do except pay a mechanic
Bobby V

Ok, checking the codes is easy enough. All you need is a paper clip and a pencil and paper. Look up the ALDL connector a so that you can identify the proper terminals and then all you have to do is jump the diagnostic terminal to ground and count the flashes on the CEL/SES light. Counting the flashes is easy the CEL/SES light will flash each code 3 times the, first code will be 12 A single flash followed by 2 flashes a( code 12 tells you that the ECM is able to enter the diagnostic mode) All other codes will be repeated 3 times and then they will repeat. When you get back to code 12 you will have all of the stored codes.


https://www.bing.com/images/search?...A3492453BA3DB1778FF1824854F0CF7B7&FORM=IQFRBA

 

[evilunclegrimace]

After you record your codes you can set the Minimum Idle Air Rate. This easy enough. run the engine until it reaches normal operating temp. Shut the truck off. Then remove the air cleaner, ground ALDL terminals A&B with your paper clip, turn the key on but do not start the truck and look down the Idle air passage on the throttle body and verify that the Idle Air Control Solenoid (IACS) pintel is fully extended and seated. This is the round screw in solenoid on the passenger side of the TBI with the square black 4 terminal plug on it. Then disconnect the IACS plug. Start the truck and set the MIAR to the specified RPM.

After this step set the Base Timing. On the Passenger side of the firewall there is a T shaped cover, remove it and find the single wire that is tan with a black stripe. It will have a connector,
separate the connector and set the Base timing ( zero degrees) You may have to adjust the distributor to get the timing correct. Re check the MIAR and then shut the truck off, remove the paper clip, reassemble the truck and clear the codes ( disconnect the battery for ten seconds, longer is fine) Reconnect the battery and start the truck.