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DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
Codes are 12 and 34, brake cleaner will start car, it idles ok, once I give gas it climbed to 2800 then dies off fast Then runs bad. Fuel pressure at rail is 40.
Dad died in 2016, I’m in the Corps and just got his car home. Not a lot of time to work on it.
Just sprayed down the MAF tonight. Has new fuel filter. Bought a fuel pump and assembly, but think the pressure checks out.
It’s a 89 formula. Think dad replaced the distributor. I found some new cam sensors in his tool box and 4 injector o-rings...? I disconnected the fuel supply the other day keyed on twice then disconnected the return and did the same. And that allowed me to get it up one time, I got it to 6k rpms before it died out. Now it’s back to 2-3k rpm.
Original grey body injectors?
fresh fuel ?
have you diagnosed the maf code 34 with a service manual?
maf cleaner used on the maf or brake cleaner?
original injector? Not sure, they are grey but I found a bunch of old prongs in his tool box. Fuel was about half a talk I added a can of sea foam and roped off tank with premium fuel. Recently syphoned most of fuel out. No water in the cans looks and smells good. I used auto zone MAF spray cleaner, with it hooked up I spray brake cleaner into the intake fires up runs like ****. With it running I disconnect sensor it runs better still slight changes from about 650-800 rpms periodically. Reconnect the sensor it immediately dies out.. will it always dies as soon as sensor is reconnected or does that indicate a bad MAF? I haven’t check resistance on it yet, still looking for the procedures and range.
Last edited by Fixndadscar; Aug 30, 2020 at 03:19 PM.
Reason: Typos
You might want to start out with injector replacement. Even if they ohm out ok there probably gummed up with varnished fuel. they are not a good design injector there coils short. look at soothsay fuel injectors for replacement injectors.
bosch 3s will work but should be retuned so they don't run lean. delphi's are more plug and play. investing in a old otc scanner or tuner pro and mates.net extreme aldl cable will help you diagnose if its a maf issue. idle you should expect about 6-8 grams per second.
Well verifying it with your chart. I was worried at first it might be Ecm.... but MAF disconnected it runs better. Which checks out with what you just sent. And with it disconnected I’m now going from code 34 to 33 which checks out ECM should be good! I just ordered a new MAF from auto zone think it was about 150$ be here tomorrow to see if this fixed my issues. If not I’ll check the injectors next! Thanks brother! Keep you updated. Next I was thinking about some Koni shocks I heard they are amazing. Then would like to see about getting a bit more power. Interior is great, just got new hood supports. And need a new spoiler (cracked) Hawks is a bit pricey at 479 plus 200 for shipping to Ca. Any advice on those parts, or what I should do for some more power? (Once she’s running smooth again.
There are a lot of junk mafs made for tpi . Some don’t even have a burn off wire but can be addressed with tuning out the code 36. Delphi and Used Bosch are the best .
but has to be for 86-89 , 85 tpi maf is different
Well replaced MAF, code was still there. Disconnected battery, reconnected and code went away. Still no start, I found a fuse panel diagram that is different from the fuse box fuses. Online it calls for a 20 a on the injectors x2.... the print on fuse box says 10a, and it’s missing 10a for fuel pump, and oil pressure, electric cluster. (But fuel pump runs..?)See photos below, not sure if they are correct (diagram off YouTube) thanks!
With the no start, check basics. Injector pulse with a noid light, spark and fuel pressure. Also try spraying starter fluid in the vacuum line to the vacuum booster. This will be a big leak but just to see if it pops off. The injectors fuses should be 10 amp and there should be a 20 amp fuse for ecm and fuel pump next to the battery.
Had to you tube the noid light. Autozone didn’t know either, and does not sell it. The fuel pressure is 40 psi. The 20 a fuse checks out ok by battery.
Starting at firewall moving forward passenger side checking ohms on injectors it reads: 16.4, 11.6, 10.3, 10.2
If you unplug the 5.2 ohm injector you might have injector pulse. It’s probably shutting down the injector driver in the ecm. If your parts store is to stupid go somewhere else. https://www.autozone.com/test-scan-a...ece/948078_0_0
harbor freight has them too. But you might skip getting them and replace the injectors and see where you’re at.
Unplugged injector 7 with the 5.2 ohms still no start. I’ll hit up parts store tomorrow to see if they carry the injectors. Any specific brand you recommend for these cars? Wish I lived close to ya, I’d have to have you over for ribs and beer! My son was trying to help and turned car over while it had the Gm code reader was hooked up and flipped switches on the top from Ecm a-b to ccm-abs...... trying to teach him but hoping it didn’t damage Ecm. I know the book says do not start it, just key it on. Only code that flashes is 12.
The engine should start, or try to start, with the brake cleaner regardless. It sounds like you may have flooded it with all of this trouble shooting. Without adding any brake cleaner to the intake, floor the accelerator pedal while trying to start it for a few seconds or so. Then let go of the pedal and see if she starts without the brake fluid. If not, then spray a little brake fluid into the opened by hand throttle body and see if she at least catches...
Having the aldl jumpered and cranking or even running will not hurt anything.
im sure you will pay more and probably get a poor quality injector at a parts store. Hit up southbay fuel injectors
She’s alive, still struggling new injectors next. Just got to figure which ones on that site, I’ll just call them. No more service light after the MAF. Trying to upload a video but it’s not letting me... 500-700 rpm random bounce at idle, 40 psi strong. Good signs this morning!
Rob, I let it sit over night, disconnected fuse for ECM. Trickle charged batteries (they dropped to 37%, it’s new, just a lot of starts) then brake cleaner to start. Drove down road about a block, tried getting on it, did not jump in RPM with gas peddle floored, died. Disconnected the number 7 injector (5ohms) brake cleaner and was able to get back.
Tuned performance, I called that company they said I need injectors with 22 lbs, part # 4447 at $165.99. But they are out of stock and won’t get more for two weeks then would still have to ship then to me here in California.
If those are Bosch 3s they should be tuned. There Delphi’s are a direct replacement.
you could always check with fuelinjectionconnection but would still tune.
they double o-ring them unlike southbay that presses on a adapter.
noisy injector by design just a FYI.
Well just hit up fuel injector connection. They offer 22 Delphi with lifetime warranty for $412... hope these are worth it. They said South Bay are rebuilt Bosch and not very good and that’s why they were so much cheaper?
Well just hit up fuel injector connection. They offer 22 Delphi with lifetime warranty for $412... hope these are worth it. They said South Bay are rebuilt Bosch and not very good and that’s why they were so much cheaper?
I don't like when the competition speaks negatively towards another service provider. Was at South Bay not too long ago, picked up a new set of injectors for the wife, and had a set rebuilt for my turbo GTA. Handed them the injectors, and despite a serious work load on their hands, they called the next morning and said they were finished, and to come and pick them up whenever I'd like.
Ya no idea haven’t bought from either company. Southbay was just out of stock and would take about a month. So I paid double, but will have them by Saturday... just want to get car running, then maybe look at power options.. still learning this car and who to go with.
He said that the injectors I bought are dry, that the old version had fuel run through them that these 22 Delphi are one of the best out there. Think I over paid? You guys got me wondering if I should have waited the month lol.
Josh, it happens, it's no big deal. Ideally though, you should have bought a used set of Bosch 22# injectors for very cheap (not in high demand), then have South Bay rebuild them for you through their service. Would have saved at least half of the amount you already paid. But either way, the stock Multecs had to go...
dirty car, leaking gaskets Ect. Been a pain in butt with four kids and a wife haha. I have been taking my time, soaked and scrubbed plenum, runners, removed all gasket and started cleaning the top of my engine. Egr valve looks old but looks ok... any advice on if I should tear more down or replace anything while I’m this far? I’m almost ready for reassembly. Still got some more cleaning to do. (Used super clean from Autozone, it’s amazing, left a bit of a haze on runners but used the heavy duty gojo wipes)
I was also recommended that I should have went to 24 lbs injectors instead of 22..? When I ordered my injectors I received a set of orings (see photos) any idea what those are for? They are different sizes, and injectors came with some on already.
im also trying to find torque specs for the fuel rail, runners, and plenum. And gaskets do I just push tabs in and bolt, nothing needed to add to them?
then on a side note, ever done a miny ram? A guy suggested it to me. Never done one..? Also is there time frames to remove things like the charcoal canister or anything?
as always I appreciate you helping me restore my dads old car,
Here’s the photos: Super strong 10-15 minutes filling runner tubes and rinse, spotless. From autozone Little rust, replace, no issues I know of yet. After using cleaner Almost ready to install, just need torque specs. Dryer duct cleaner brush from Home Depot, easy to manipulate to clean runners and plenum What are these (standard p# SK24) all different sizes...? Do I need to add anything to these or just tab in bolt and go?
If you search ttop350 posts you will find a relocation picture of the cop.
no need to goto 24#hrs on a stock 350 you don’t need more fuel it would just require tuning that’s not needed. If the intake gaskets not leaking might as well leave alone. The pegs hold the gaskets in place.
watch the gaskets orientation. The oval slot is not the same on each side.
i just snug down the plenum and runner bolts might be able to find a spec online maybe 11-15 ft lbs just a guess.
What did you circle in red there? Mine does not have that screwed into fuel rail. Looking up the photo for the cop relocation not seeing it yet. The bolts were tight as hell on the fuel rail. Do you happen to have the torque for those?
Disregard... it’s late I’m going to bed, cold start injector.. as stated above. Just need those torque values if you got them in the am. I’ll tear this apart. Thanks again brother.
Seems alittle high for torque values. TPI Torque Specifications
Below are the torque specifications as designated by GM for Tuned Port Injection intakes. Please note that some specifications are in lb. ft., and some are in lb. in.
Manifold to Runner Bolts 25 lb. ft.
Runner to Manifold Bolts 25 lb. ft.
Fuel Rail Attaching Bolts 15 lb. ft.
Throttle Body Attaching Bolts 18 lb. ft.
Throttle Position Sensor 18 lb. in.
Idle Air Control Valve 13 lb. ft.
Throttle Body Coolant Plate 27 lb. in.
Throttle Body Cover Plate 30 lb. in.
Power Brake Vacuum Fitting 108 lb. in.
Fuel Line Nuts 20 lb. ft.
Fuel Tube Bracket Bolt 25 lb. ft.
Fuel Pressure Connection 115 lb. in.
Pressure Regulator Base to Rail 44 lb. in.
Pressure Regulator Bracket 44 lb. in.
Outlet Tube to R/H Rail Retainer 44 lb. in.
shes alive!! Pulled a late night, couldn’t stop. The fuel rail was a good idea to repair the seals. They were pretty bad and the small pipe to regulator was corroded in had to take vice grips with a cloth, then buff the burrs. But she’s clean and does a burnout now! I’m pretty excited! Thanks so much for the assist. If you ever in California look me up dinner and beer on me brother. Always good to have an expert to bounce ideas off of. Next I have to do suspension it’s pretty rough and steering boots look bad and makes a lot of off and on squeeling. Also noticed what appeared to be a bit of oil under the new gasket in center on driver side. That was also there before tear down.. will have to look into it.
