Tbi swap build thread

[68 TT]

Originally Posted by rfmaster

BCC: ATKN
Year 1990
PROM Size 32724
ECM #16144288
Program ID: 160 ($A0)
Product Line: C1/K1/P1
Engine: LB4 4.3L
Transmission MD8 AUTO (700R4)

This ECM was specifically developed for V6 application. ECM will run V8, but limp mode will not work and calibration is off for a typical V8. However, you can modify VE and SA tables together with larger injectors. As is good enough to start your motor, but as for driving - very iffy.

//RF

The 1227747 ECM's are so common you should be able to find a 5.7 OD auto version pretty easily and save yourself a bunch of time & effort.
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[camaney]

suscribe

[65Guy]

ok i decided on the nv3500. So my question is do i need a drac to make my vss work or can i wire the tailshaft mounted vss right to the ecm?

[rfmaster]

Originally Posted by 65Guy

ok i decided on the nv3500. So my question is do i need a drac to make my vss work or can i wire the tailshaft mounted vss right to the ecm?

I did a bit of search on this subject since I have never dealt with NV3500 trany. From what I could find the NV3500 employes a 40 pulse VSS (per shaft revolution), so that you'll have to sue a DRAC or Dakota digital buffer module to arrive to 2000 ppm signal that TBI ECM (aka 1227747) is expecting.

The Dokota Digital converter module is a Swiss army knife equivalent of GM DRAC minus the PITA. This module is pricy, but time and effort may justify the initial cost. Check their website SGI-5 Universal Signal Interface Unit.

//RF

[65Guy]

ok, also i have a question about dynamic efi. I have browzed there web site how hard is it to learn how to use.

[rfmaster]

Originally Posted by 65Guy

ok, also i have a question about dynamic efi. I have browzed there web site how hard is it to learn how to use.

It is a lot easier than trying to burn own chips. There is a main thread (as well as several smaller threads) on thirdgen.org that deals with EBL user questions. Unless you have a fire breathing monster of a camshaft+engine EBL can handle.

I run EBL on all my conversions - see youtube videos. The key to TBI is selecting camshaft that provides about 14-16 in-Hg at idle and steady idle. After market camshaft with LSA of 112deg and higher with up to 214deg at 0.050 will do the trick. Tighter LSA (<112deg) results in lumpy idle which screws up MAP sensor readings and ECM will over fuel the engine. Long duration camshafts >220 deg also create havoc for O2 sensors at idle. Our trucks need low end torque, and high RPM HP is never really needed in a street truck. What we need is flat torque from 1500 to about 4500 RPM to get the weight going (and keep it going). A good RV cam will do this trick without creating problems for TBI system - for example CS1014R (flat tappet).

//RF

[lahnen]

looking to do a tbi swap to my 86 k30 dump. i got a 89 c2500 that used to be my dd. i plan on pulling the motor, wiring and all relays/sensors from under the hood, and computer soon. is there anything else that i will need from the donar truck. also am i gonna have to replace the 86 wiring under the dash or will i be able just to put power to the computer to run all engine componets.

[65Guy]

Im redoing my wiring on the 65 tbi, i would like some pictures of the swap done on 60-66 trucks please.

[rfmaster]

Originally Posted by lahnen

looking to do a tbi swap to my 86 k30 dump. i got a 89 c2500 that used to be my dd. i plan on pulling the motor, wiring and all relays/sensors from under the hood, and computer soon. is there anything else that i will need from the donar truck. also am i gonna have to replace the 86 wiring under the dash or will i be able just to put power to the computer to run all engine componets.

One of the key components is VSS. Depending on the donor vehicle VSS can be PITA. Do you have donor identified? Also, you do not have to replace any of the under dash wiring - EFI is a standalone system and is adapted to your 86 harness - fuse box.

//RF

[Low Elco]

A guy a few posts back asked about 700r4/4l60 integration. What's involved? I have an 87 sb, 350tbi/350 and of course I want the od. Any info on what might be involved? Really kinda thinking of getting a 94/95 computer and running tbi/4l60 like I had in my 95. Is this easy? A pipe dream? Anyone done it? I have 2 90 2wd burbs in a yard not far away that are still fairly complete with electronic speed outputs for the 700's. My 87 t350 is a cable. Will the tailshafts swap? Can I just put a later cluster in my truck? Sorry for all the questions, but I've been wondering. Thanks, Chip.

[rfmaster]

Originally Posted by Low Elco

A guy a few posts back asked about 700r4/4l60 integration. What's involved? I have an 87 sb, 350tbi/350 and of course I want the od. Any info on what might be involved? Really kinda thinking of getting a 94/95 computer and running tbi/4l60 like I had in my 95. Is this easy? A pipe dream? Anyone done it? I have 2 90 2wd burbs in a yard not far away that are still fairly complete with electronic speed outputs for the 700's. My 87 t350 is a cable. Will the tailshafts swap? Can I just put a later cluster in my truck? Sorry for all the questions, but I've been wondering. Thanks, Chip.

Hey Chip
The 93-95 PCM's are (were for their day) advanced powertrain computers and much more powerful than C3 ECM found in 87-92 C/K's. The PCM can control TBI and 4L60E/80E as well as 700R4. It can also be used with manual gear boxes - all of this requires modifying EPROM. This is a long discussion (PCM mods) and better be done else where. There is a lot of information available - TGO, moates and elsewhere.
Regarding Spedo. This is where it gets a bit tricky since 93-95 used electronic speedometers. The VSS produces 40 pulse per shaft revolution which gets passed to DRAC module. DRAC module has three outputs which feed into anti lock brake system computer, cruise control and PCM.

To swap into 87 I would look into converting 4L60E VSS from electronic to mechanical drive with addition of inline VSS module to drive the PCM (assuming that there is no cruise control). This swap would require removal of reluctor ring pressed onto tail shaft and installation of drive gear to drive driven gear. You'll also need speedometer gear housing. For more info see link below.

http://www.transmissioncenter.net/sp...n_______va.htm

//RF

[Low Elco]

Oy. So, best to keep fairly close, year to year? Seems a bit of a mess. I'm fine iwth swapping the housings, but the rest is a tad muddy. Thanks for the info, though, answered a lot of questions.

[manimal]

I have a question regarding the EGR solenoid.My CEL comes on spuratically.
I have checked vacuum at TBI=0 at idle,increases with throttle.
no vacuum at egr side of solenoid with engine on or running with throttle.
I can move the egr valve manually and the idle changes,but doesnt stumble.
Does this sound like i have a BAD solenoid?
Vehicle in question is 1989 Suburban R2500 454 TBI(2wd),automatic.
Thanks!

[rfmaster]

Originally Posted by manimal

I have a question regarding the EGR solenoid.My CEL comes on spuratically.
I have checked vacuum at TBI=0 at idle,increases with throttle.
no vacuum at egr side of solenoid with engine on or running with throttle.
I can move the egr valve manually and the idle changes,but doesnt stumble.
Does this sound like i have a BAD solenoid?
Vehicle in question is 1989 Suburban R2500 454 TBI(2wd),automatic.
Thanks!

Follow up questions:

1) CEL comes on sporadically - which DTC codes are set? Get wire jumper across pins A & B of ALDL and count CEL flashes (groups of 3 starting with 12)

2) If you apply vacuum to EGR valve with a vacuum pump you should see the valve move and there should be some change in idle quality. Too much EGR and the engine should stall. On high millage trucks there is a lot carbon and oily crud build up in the EGR passages restricting amount of exhaust gases reaching intake manifold plenum. The best thing to do is to carefully remove EGR valve and take a small brush and carb cleaner and try to remove, clear the offending crud.

Depending on EGR type you have it may hold vacuum or slowly bleed it of. A blown diaphragm will leak instantly - use a hand held vacuum pump to check EGR diaphragm.

Depending on calibration EGR valve is enabled when truck is in motion and certain other parameters are met. To check for EGR vacuum control side operation I use a vacuum hose and T with a vacuum gauge temporarily mounted on the windshield (duct tape can be used). The vacuum take of point is between solenoid and EGR valve. If you see vacuum while driving - solenoid is supplying vacuum to EGR valve. Check EGR diaphragm first. Check supply vacuum hose as well (between TB and solenoid input).

If you do not see vacuum then I would check ECM control circuit. The EGR solenoid connector should have two wires - pink-black and gray. The pink-blk should have +13.8 Vdc when engine is running (IGN is on). The gray wire is a control circuit - ECM will pulse this line on-off to control amount of EGR. Most DVM's averaging is too slow, but higher end DVM's may have a frequency function and can pick up the PWM waveform. Naturally Oscilloscope is the a weapon of choice!

//RF

[manimal]

At the moment I cant remember the codes,but I do remember it saying the EGR system,check for operation of the valve,check the solenoid,check the plug to the solenoid.
The CEL light comes on at very strange times. I have driven half way to Sacramento(200 miles) with it NOT coming on,then I have driven down the street about 5 miles and it comes on.
I do plan on cleaning out the EGR passage,so a new valve may be in order anyway.

[rfmaster]

Originally Posted by manimal

At the moment I cant remember the codes,but I do remember it saying the EGR system,check for operation of the valve,check the solenoid,check the plug to the solenoid.
The CEL light comes on at very strange times. I have driven half way to Sacramento(200 miles) with it NOT coming on,then I have driven down the street about 5 miles and it comes on.
I do plan on cleaning out the EGR passage,so a new valve may be in order anyway.

Well, lets get some basic information squared away before jumping to any conclusions. Pull codes - they should stay put in ECM memory unless battery was disconnected. We'll go from there on.

//RF

[manimal]

Code 32 comes up. I checked the pink/black wire at the solenoid,on my DVM it reads 12.01. I dont have a vacuum pump (other than my wife!lol),so I have to draw vacuum the old fashioned way. When I do there is NO movement n the egr valve when the vacuum source(me) is hooked to the manifold side of the solenoid with the key "ON" engine "OFF".

[rfmaster]

Originally Posted by manimal

Code 32 comes up. I checked the pink/black wire at the solenoid,on my DVM it reads 12.01. I dont have a vacuum pump (other than my wife!lol),so I have to draw vacuum the old fashioned way. When I do there is NO movement n the egr valve when the vacuum source(me) is hooked to the manifold side of the solenoid with the key "ON" engine "OFF".

EGR solenoid acts as a proportioning device - metering amount of vacuum that reaches EGR valve diaphragm. The fact that you see about 5" inch of vacuum between EGR control solenoid and EGR indicates that control circuit is functioning, but EGR valve diaphragm bleeds off vacuum very quickly. Not being a betting man I would say that you may have a leaky EGR diaphragm. You can temporarily connect EGR valve directly to a manifold vacuum port and if there is no movement - it is time to replace EGR valve!

In the absence of the handheld vacuum pump I would take it off and take it to a parts store - most of the time they have handheld pump handy.

//RF

[manimal]

I hooked a vac gauge up to the egr port(between solenoid) and drove it in town and freeway. Vac reading never got above 5" and would stay there for about 10-15sec and then drop to 0.

[manimal]

Thank you very much.

[rfmaster]

Originally Posted by manimal

Thank you very much.

An - unrelated question! On your '89 454 Burban you do not have an AIR pump, right? Is it CA or Federal certified (do you know). The reason why I am asking there was a post recently with a question when GM stopped using AIR on BBC TBI trucks.

//RF

[manimal]

It's a CA truck w/A.I.R.

[manimal]

Another question, would a leaky diaphragm also be the reason it will hold 5" for 10-15sec. and then drop off to 0,repeating that over and over. Or is that the way the system operates,open then close cycles?

[manimal]

Originally Posted by manimal

Another question, would a leaky diaphragm also be the reason it will hold 5" for 10-15sec. and then drop off to 0,repeating that over and over. Or is that the way the system operates,open then close cycles?

???

[rfmaster]

Originally Posted by manimal

???

This was in reference to fuel pressure regulator???? Or ??