My new 350 build is running rich (Block Learn Reading of 105 with scanner) and I am wondering if the new injectors are the culprit.
I was planning on Ford SVO 24 injectors since a lot of people here were using them. At the time the Summit sale person said they didn't have or were out of (can't remember which right now). He said the Trick Flow (TFS 89024) were the same thing or built by the same manufacturer so I went ahead and got them.
I did notice at the time of installation that they were shorter than the OE injectors but figured since they were supposedly the same as the Ford SVO 24's it would not matter. Now that I am having idle issues that I can't get rid of I am second guessing the injectors and thinking they could be what's causing it to run rich.
The OE injectors measure 80mm from top to bottom. The TFS injectors measure 72mm.
All of the difference being in the bottom half of the injector; where it rests against the intake, to the bottom of the injector.
Is this the same way the Ford SVO 24's are?



GM 350/L31 4 bolt shortblock #12556121
Patriot Performance Freedom series 190 CNC Bowl Blended & Gasket Matched 2.02"/1.60"/60cc Straight Plug
Fel-Pro Head Gasket #1094 .015 in. Compressed
Comp roller Cam #08-501-8 (212/218 .488/.495 112 LCA)
Comp Magnum 1.5 rocker arms #1417-16
Comp timing chain and gear set #3136
GM Lifter kit #12371042
Edelbrock intake #3860
BBK adjustable Fuel Pressure Regulator
Hooker Super Comp headers
Autolite platnum plugs #5224
MSD 8.5 Ignition wires
Magnaflow Exhaust

 

they fit but you have to use the clips to hold them up.. the bottom is just suspended but the bottom o ring goes in the bore to seal ok.. did you retune the ecu for a 24? those rich blm #'s might be because the 5.7 ecu is set up for 21.45lb (22) 24 trick flows are a disc injector that is much quicker than the old stock ones so for the same pulse width you get more flow.. They IMO were not the right choiice as the Bosch are the same specs as the old.. I think if you go to PCM for less and have the chip burned properlu that you will be ok

 

Thanks irocuroc
My concern was that they were suspended and not all the way down in the intake.
I thought they were sealed ok but I thought it might mess up the spray pattern or injection enough to cause issues.
So you are saying with the stock prom I am getting to much fuel being a 24# disc injector?
Would I be better off eating these injectors and get different? Or would it so just as well by getting a different prom by someone like pcmforless or FastChip.
I was under the impression that the '85 was very adaptable to changes and will support a lot of changes without changing prom.
I have been curious with a '85 ECU system what you can change or take into consideration when making a new prom such as cooler thermostat, timing, shifting etc.
Thanks
Tim

 

Tim, you're running a 350 ci motor right? ...what "stock" tune, one for a stock 350, or one for a stock 1985 305ci TPI engine?

....a stock 350 tune from a 1987 to 1989 TPI car should EASILY be able to handle the changes you've made, but if you're still running that 305 tune, well then I think you've found your problem.

...for the sake of argument, yes, ideally a stock 350 tune would need to be calibrated for the 24# injectors, and with an aftermarket cam, a little tuning can find a little extra power, but for what you have, it shouldn't be absolutely necessary. I'm running a good bit more cam than you, AND I have 24# injectors, and my stock tune runs fine. I do have an aftermarket tune, but I keep switching because quite frankly I can't tell which runs better! ...but for more aggressive mods, eventually a tune becomes essential.

*edit*

The injectors being a little short shouldn't effect the spray pattern.

Where are you located?

 

Abubaca
Yes I switched it to a 350 GM shortblock instead of 305.
I take it by stock tune you mean ECM or prom chip. Yes it is the stock '85 305 ECM and prom but I did use a new 350 knock sensor & module for a '85 vette.
Like I mentioned, everything I've researched before I started the build the '85 ECM or prom is suppose to be very adaptable to changes and will support quite a bit of mods or changes without changing prom. Thats why I ordered the mild cam I went with and didn't mess with having a new prom chip burnt. I would think I may get a little better performance out of a custom prom but it would run and idle decent with the original. Thats why I was wondering if maybe the injectors were the problem.
Maybe I'm wrong?

I've just about eliminated everything else that could be causing it including:
Replaced MAT sensor and pigtail, Coolant sensor, O2, IAC valve, EGR valve & sensor
My TPS is working and adjusted corectly
MAF sensor seems to be working (stalls when unplugged)
No vacuum leaks
No Codes
I just picked up a used MAC scanner for my car at a a swap meat and have started playing and learning to use it.
Yesterday I came up with a Block learn of 1.1.5 - 128 in open loop
1.0.5 - 61 in closed loop
But not sure what that is telling me?
Oxygen sensor - 923
TPS .56
Prom ID 7739
IAC vote 41 Man air temp 47
coolant 80c (170 thermostat)

I am located in Ohio near Bellefontaine (40 miles NW of Columbus).

 

I'm no tuner, but I see 2 problems here, if I read correctly.

305 PROM on a 350 with 24lb injectors.

Get a 350 PROM (even a stock tune) & you should see a big difference.

 

do you hAVE an adjustable fuel pressure regulator?

check your fuel pressure if so with your vaccumm line unhooked.

basically what your data is saying, is your running absurdly rich which as stated by the above poster may very well be from the fact that you are running a 305 prom. although i think there is more to it by the sounds of it......

with a block learn of 60-105 you are running like 2/3 to to around 1/3 richer than need be....... i'm honestly kind of scratching my head at this, did i read this right? pay attention to your maf sensor gr/sec out put reading and make sure it sweeps smoothly up and down. also make sure your 02 sensor is getting proper cross counts.

 

I agree, but I suppose it's a matter of terms like, "very adaptable" and "quite a bit". In my opinion, the 85-89 MAF cars ARE in fact very adaptable, but I don't think it's fair to ask it to compensate for an additional 45 cubic inches, AND a bigger cam. At least with those mods, it can TRY to adapt via inputs from the cars sensors. ...THEN throw in the 24 pound injectors. The computer still thinks they're 19 pounders.

You could possibly have another problem we haven't touched on, but you can't even begin to trouble shoot when we KNOW you're so far off with the computer tuning.

Once you get a proper tune, then trouble shoot any problems you may still have.

*EDIT*

Yes, by tune I mean the program/prom that the computer is running. I've had good dealings with Alvin at PCM4Less. I haven't got into doing it myself, but others have had a lot of luck with programming their own cars as well.

 

run the fuel pressure at 36, then you moght be ok with the 85 tune

 

...or get a 350 tune, and you might be ok running a 350.



...I feel like I'm the only one not getting this....

 

Well it sounds like before I do any more guessing or trouble shooting I need to get a different tune or prom made.

Yes that was the block learn readings I got with my used MAC Brainmaster all test I just scored at a swap meet for $10 but can't guarantee its accuracy. But it does look brand new or hardly used.

I do have an adjustable FPR and had it set around 47 most of the time. But I think it would probably be best to get a new prom made before trying to back it down to far.

Flaming-Ford
if a new tune don't get it that will be the next thing I check out is the maf sensor gr/sec and 02 sensor cross counts.


Abubaca
I went to PCMforless website and they may not do proms for '85. I'll have to call.
Custom Programming 1986-1993 Price: Starting at $134 + shippingDescription:
After completing the payment process you will be taken to a comprehensive order sheet. Pcmforless.com will use the information on your order sheet to build you a custom prom programmed specifically for your needs. We will send an automotive memory adapter. This adapter plugs between your stock chip and stock computer bypassing the stock chip's calibration. Installation is a plug and play operation and typically takes less than 15 minutes. Updates for future modifications are $50. We do not support 86-92 TBI cars or trucks. Do not send in your stock PROM or PCM!
Thanks for the input guys, I'll post back to let know how it works out.

 

Step #1: Lower your fuel pressure!

 

OK, I just took a deep breath.

Serenity now. Serenity now. Deep breath. Ahhhhhhhhhh........

Look. Adjusting fuel pressure as a fine tuning tool is a GREAT option. If Tim's car was set up perfectly, with NO other foreseeable issues, then yes, fine tuning the pressure to see if it is in fact a fuel issue is a great tool to help find a problem. Then you find that actual problem, fix it, then return the pressure back to "proper" fuel pressure.

First, the car runs best at one exact pressure. Each and every motor may be slightly different, but they're all about the same, give a car's specific mods. If it's set properly, you can't simply change it to solve a problem.

But regardless, WE KNOW THE PROBLEM!!!!!! ...why on earth would you guys recommend he NOT FIX THE KNOWN PROBLEM!!!!!!!!!!! I just don't understand.

Tim, I can't tell you why PCM4less doesn't offer tuning for 85. Possibly something different with that first year of the TPI? A physical computer difference maybe? I honestly don't know. Maybe they do, and the 86 is a typo??? ...probably worth a call. Alvin is a good guy to deal with though. His mail order tune worked for me, and being in NC, I plan to have my future engine build tuned by him in person.

...the guys on the DIY prom board may know if you post up over there.

 

PCMforless does not do proms for the '85 after emailing them.

I called FastChip http://www.fastchip.com/ and talked to the guy their that does the prom tuning.
He does '85 prom tunes. Started giving him some of my info and questions but he needs to know more about my injectors to get it right since its a disc style injector.

He hasn't done a lot with the disc style injectors other than Lucas injectors.
He said he wants to get it right and without knowing more on these injectors would be a guess and he did not want to do that. Could burn rich at mid range.
He knows Trick Flow does not make its injectors and would need to know who makes them for Trick Flow.
He said he could get it close if it would be Lucas because he is familiar with them. Not so sure about Accel or Bosch but he said they are one of the same.
And if they were made by Venom I should throw them away and get different before I get a tune.
Can anybody give me some info on these injectors?
I wish now I would not have got these, and I've already used them so can't return.
He also said Summit owns Trickflow and thats why they recommended those.
Thanks, Tim

 

Did PCM say why they didn't do 85 cars? I'm curious.

...as for the injectors, I wish I could be more help. One thing I might do is to ask Fastchips what injectors HE would recommend for the motor you have. Lots of us have had great success with various incarnations of Ford/SVT/SVO injectors, and they can be found almost anywhere, and at a pretty good price. I understand you've already got yours, and I'm not suggesting you HAVE to replace 'em, I'm just saying if it's the difference between gettin' it right, and NOT gettin' it right, it's something to consider.

...but I imagine the info is out there. Have you called Summit about them yet?

 

trick flows are lucas disc made by SMP (standard motor products) same as accell, summit, racetronix, msd. all the identical injector

 

I ordered my new Prom tune today from Fastchip.
Hopefully this will take care of my idling/stalling and running rich problems.
I'll post back to let know.

Abubaca PCMforless in their email reply just said that they were sorry but they started with the '86 year.