Chevy 350 with new TBI in FJ40 problem... (3 Viewers)

[ledbellyhead]

I was hoping to get some help here, the people at painless wiring blew me off even though it is their harness.

I just put TBI on my small block in the landcrusher and thing is giving me problems I can't figure out or find answere to...

It has power and sounds good until it starts to warm up, then it sounds like it is starving for fuel, no backfire though, it will start to idle down and then just die, has no power when warm.

Coolant temp sensor checks good acording to resistance readings on internet, dead on...

Fuel pressure is great, 14, dead on, always, no fluctuation.

New ignition module, plugs, wiring, cap and button, timing set according to manual, 0 deg. with brown wire unhooked.

Used a painless harness, the computer is for an auto, but the park swich is wired closed. No vehicle speed sensor, no knock sensor, no egr.

I think that everything else is wired correctly.

It will still stall when the thing gets warm with the IAC unhooked.

If anyone has any ideas, please help me...

Thank you,

 

[nicholastheczar]

Ive been working on getting my TBI setup working properly also. Mine is the opposite of yours. It starts rough and runs rich and once warm runs like a champ. I've gone through and looked at all the senors I could, replaced a lot of them, installed new injectors, etc.

You might consider getting an ODBII reader so you can see what your values are. I've been driving mine around for about a year now. It runs well enough but not great. Last week I took it to a shop to have them try to figure out what I could not.

nick

 

[fyresq]

I know you said your coolant temp sensor was good but are you sure? Really seems like the glaring issue.......

 

[Cdaniel]

What condition is the O2 sensor and wiring?
It's a major contributor to the control puzzle after the temp sensor tells the ECM it's warm.

 

[fieldsken1]

i would say o2 sensor also

 

[Mr. Toad]

...
It will still stall when the thing gets warm with the IAC unhooked.
...

What about with the IAC hooked up?
When you unhook it, is the IAC in the closed position?

 

[terrx]

What's the broadcast code on the ECM? What color coding on the injectors?

 

[ledbellyhead]

Thank you all for the help, I am not sure what a broadcast code is? Is this the same as a trouble code?

The IAC is shut all the way I beleieve, I removed it and it looks good, when I set the thing by pinning terminals A&B together it makes clicking sounds until removed, it doesn't sound bad, I just wasn't expecting it, it almost sounds like a worm gear slipping, I assumed it was where it was bottomed in the Throttle Body. The piston looks clean where it has been stroking. It seems to have no effect on the issue.

I had read some more about everything and removed the wire to o2 sensor and ran it, it still did the same thing after warming up. I thought it went into some run safe mode, but still acted the same. The wiring is brand new, I can tell it is different when unhooked. I got about 1.05 Volts out of the sensor when I revved the engine the voltage would drop a little, but not much, when the engine stalled, it droped to nothing, but it looked like the voltage was dropping before it actucally stalled, this was with it unhooked from computer, which indicates to me that it leaned it out or something.

I checked the resistance on the coolant temp sensor with the chart found on internet and it was dead on from cold to warm, could it still be bad, it sure does seem like the issue to me, but I figured it was like an RTD we have installed on lines at work for temp. sensors.

I did the code check last night, it wasn't run for long, it flashed 12 three times by the 1 long flash, two short, then 3 fast flashes, three times, then 12 again.

Code 3 ? This doesn't exist does it ?

The thing is I was tired and thought it was 33 which is MAP, since I am upset and throwing parts at it I went and purchased a new one even though it made no sense to me, sure enough, it didn't change a blasted thing.

What do you mean by color coding on the injectors ?

Thank you for your help.

 

[Gumby]

Did you set base idle speed with the IAC?

IAC Reset Procedure

 

[ledbellyhead]

I did the procedure where you jump terminals a&b wait 30 seconds, unhook IAC start, adjust rpm with throttle plate screw, shut off, remove jumper, unhook battery for a minute, hook up IAC, hook up battery and start and verify idle rpm, I have no tach, but I was happy with it, and the IAC seemed to be closed all of the way. It wasn't warm enough to be stalling when I did this, but it was probably about 160, this is from memory if I got out of sequence, I was using the painless manual. Looks like I could use a scan tool, I have a simple OBDII reader, but that's it.

 

[bsevans]

You can find a lot of good info from people that have done 350 conversions in LandCruisers at this LandCruiser VORTEC Conversion Group website. It also covers TBI and is well worth joining. You can search for info related to TBI and post your problems. I'm sure there is a member that has probably dealt with this issue.

Landcruiser VORTEC Conversion Group

 

[Elbert]

how are you dealing with no knock sensor and no VSS...? just simply not using them?
You can't expect to simply unplug sensors and then have the engine run right (if that's what is going on). You will need a new ECM chip on a TBI engine made that does away with sensors you don't plan to use.

Knock sensor is critical, vss is too, 02 is ...IAC...etc..you need all of that stuff functioning in my view, you also need to make sure the base timing is set correctly with the jumper wire unplugged.


I think the shop manual says something about a proper ECM will flash one of the codes three time (i've forgotten which one) this just says things are normal, then after that the treal trouble codes are flashed.

you count the quick flashes...sequentially and then there should be a pause and then a longer flash, then a pasue to the next code.

three quick flases and then one long flash = code 31, Or better yet get a scan tool that works on that model truck.

 

[ledbellyhead]

I tend to dive into projects without proper research, the guy on ebay said it was all I needed to convert a carb to EFI, he has great feedback and I will probably give him good feedback if I can get this thing going, Base timing is dead on with wire unplugged, when it stalls it is not jumping around, it is probably around 8 BTDC, it is definately related to the thing warming up. I purchased a knock sensor after some reading today and then seing your last post (34 $), it did nothing at all for it. Hopefully it will make it more efficient once the thing is right... The park neutral wires are wired together, this is what painless reccomends, and says it should work fine, I may get a vss for it, but that shouldn't have anything to do with this problem sitting still should it, it thinks it's in park... All the other sensors except egr are correct, and egr is hooked up to the solenoid, and never seems to change, it doesn't open or close or anything at the point that it starts acting up and stalls. I think that the code is 33, which is MAP sensor high voltage.

 

[Mad Chemist]

I'm not sure you can get away without the knock sensor. I'm not running an EGR on mine, but do have a VSS from Jags That Run.

Regarding the O2 sensor, is it a one-wire or multi-wire with it's own heating element, and where did you mount it? If it's a one-wire, it needs to be as close to exhaust manifold as possible in order for it come up to temp properly.

 

[Elbert]

FYI...I think the 92 K1500 Pickup I use to have with TBI had one 02 sensor and as I recall it was either located in one of the exhaust manifolds or just downstream from it. IF you need any values or anything PM me and I'll look that up in the shop manual I have.

One thing I understand on TBI egines that apparently they have either different Chips or differetn ECM's between auto and manual trans equippped trucks. To remove any of your sensors you'll need to have a new chip made where the programming is altered to removed that from the programming. Its like this...the ECM is programmed to check for all the sensors it expects to see, and use. If it does not see them or it see's no values then its not coing to run right.

Classic symtom of VSS issues are "random stalling for no apparentl reason", " lack of power""the engine does not really recognize a load (like climbing a hill or heavy weight). I don't know if painless is right or not. I know I had an issue with their support on my swap...99 Vortec 5.7.

One thing I would want to know is ....on a TBI engine does it need to know if the trans is in drive if a so called automatic ECM.

You might want to just buy a ECM off ebay that is for a manaul equipped TBI engine and also get the PROM chip too.

Probally good to check this guy out TBI CHIPS

It sounds to me like you have ECM / sensor issues. Apparently timting is right.

I think TBI engines need all the sensors working, but you can get asway with no converters without any issues.

 

[76 PTO]

Is this a stock tbi motor? If it just a carb swap, you will need a new chip programed for you combo of cam and heads. It makes a big difference. The stock chip dosent know you have a big cam, etc. The knock sensor is crucial. Call Brian @ TBIchip.com He programed a chip for my motor(96 Vortec roller motor fitted with tbi) He nailed my tune on the second chip. Send him the specs on your heads and cam.

 

[terrx]

The broadcast code is 4 letters printed on a label on the ECM along with the model number (1227747 for TBI). If missing you can unscrew the ECM case and might find one inside maybe on the PROM itself. The 1227747 was used on many GM vehicles, you need to the broadcast code to know which one.

OEM injectors had color paint markings on the top of them visible when the 2-wire connector pods are removed. IIRC, orange/black were the 62 #/hr injectors used for a 350. There are serial numbers on them too, that will work if the paint is gone. Be sure they're right for the 350. Probably are but worth a check.

The ECM is programmed with the engine size & air flow (affected by heads, cam, intake, etc), fuel pressure, and injector flow rate. If it's out of sync with what you actually have it can mean too little or too much fuel is getting to the engine. The ECM can compensate for some changes, but gets confused when the changes are big or sensors are missing. That's when reprogramming comes in. Sounds like you're doing all the right things to diagnose the system. A new chip might be a good idea, by then you'll have everything else squared away.

 

[ledbellyhead]

Thanks for your help again everyone,

This is just a TBI swap, but it was a crate engine a few years ago numbers show from a 72 Chevelle.

Looks like Terrx may be onto something here...

From my ECM, 1227747, ATKX86ATKXK10922018, not real sure about the 9... Also 86ATKXK100220181, from the chips inside the removable access panel, RN Chip, Auto, HOT7747, TBI Chips. The Tag inside the module says 427081101810022. I believe this is for a 350 Auto...

On the injectors there is no color coding that I can find under the connectors. The numbers GM523627IRPD appear on both, I may be a digit off, it's kind of hard to read, one says 2239GM, the other GM2349.

From another page...

Engine | Bore ~~~|FI color| Flow ~~~| Part #
_________________________________________________
5.0L~~ | 1-11/16 |Grn/Wht |40 lb/hr |GM5235279*RPD
_________________________________________________
Pickup
5.7L~~ | 1-11/16 |Orn/Blk |55 lb/hr |GM5235206*RPD

Looks like my injectors are for a 305...

So, I can imagine it may run lean until I get the proper injectors, more money... but would that cause the problem I am having? Where it runs great and then starts going nuts, I have read about the VSS and aparently with the Park Neutral grounded, it should not pay any attention to this, and the EGR will not do anything either, so that should rule that out.

This is a stock 350 crate engine with stock heads, and cam, it has the old school chevy close exhaust manifolds, ran true dual, with the O2 sensor on drivers side about 2" below manifold flange, it was supposedly new, but what I am reading says it shouldn't cause this problem anyways. I have read that it is fine on one bank.

Like I said knock sensor is now installed and had no effect.

I want to put the correct injectors in, I am just afraid that that won't fix the problem and I will have dumped more money into the project.

Thanks again folks.

 

[Elbert]

I don't know the GM part numbers...but you might have some good luck surfing around the rock auto web site buy looking up the model truck that your TBI is from. A lot of times the rock auto web site displays the GM part numbers and you might could see if there is any difference between what you have and what the web site calls for a 5.7 tbi of the appropriate year.

 

[76 PTO]

So the chip in the computer is from brian @W tbichips.com. If it is just link up a laptop with windal (free software ) and go for a drive and log some data. send it to brian and he will tell you what you need.