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[SiFlyBy]

I have a 89 Chevy truck 350 TBI in the shop. Did a few mods to it(heads, mild cam, intake, headers, TB), got a custom tune for it from http://tbichips.com/. For the life of me I cant get it to run right all the time. So I guess what Im wondering is if any of you have the chip burner for these things and/or have any experience tuning them.

It either idles good and spits and backfires down the road or idles like fuck/dies out and runs good down the road depending on where we set the timing. ~0 degrees and ~10 degrees BTDC respectively. I would also like to get a WBO2 on it to see what its doing at such and such time to check the tune, so we got a new LM2 ordered which we should really have anyway.

It makes me sick to think that I have considered putting a *gasps* carburetor on it.

[92CXyD]

What about the idea of moding the IM for 8 inj. and using a 454 tb for more flow. Then having the ECU chip replaced for this setup.

Similar to this : http://www.turbocity.com/product_info.php?cPath=16_21&products_id=15 but w/o buying the ECU just change the chip.

I know Edelbrock did something like that but now the P/N is not available on their site.

[Joseph Davis]

It's speed density, generic chips beyond the factory tune are a joke.

www.moates.net - get an ALDL cable aka CABL1so you can datalog
www.tunerpro.net - use with an Ostrich, or burn chips if you're ghetto-fabulous

Those are about the easiest ECUs out there to fool with, and you don't have to buy the chip adapter if you are pinching pennies.  I've cut the stock EPROM out and replaced it with a socket a couple times.

I can be of a relatively good amount of help, but I'v only done a half dozen of those ECUs.  http://www.thirdgen.org/ has a DIY PROM board that is the mullet equivalent of pgmfi.org.

[SiFlyBy]

You're talking about spending $$$$ here. We are not looking for 500hp, just to get it to run right all the time. That is all.

 http://www.turbocity.com/product_info.php?cPath=16_21&products_id=15

And that just looks like a carb to TBI conversion kit, the truck already has all that stuff

[92CXyD]

You're talking about spending $$$$ here. We are not looking for 500hp, just to get it to run right all the time. That is all.

 http://www.turbocity.com/product_info.php?cPath=16_21&products_id=15

And that just looks like a carb to TBI conversion kit, the truck already has all that stuff

I know I was trying give to get a Edelbrock TBI conversion to EFI but could not find one.

BTW do you still have those HX35 for sale?

[SiFlyBy]

Thanks JD. I'm gonna look into that stuff over lunch today if I have time.

BTW do you still have those HX35 for sale?

I sold the HX a long time ago. I may be selling the HY35 on my WRX in a few months though. It depends and how tuning goes, if I decide to go the e85 route and then, finally, if I decide to go back to VGT with a HE351VE. Ill let you know first if your interested in it.

[highroller54]

before you fuck with it anymore change the spring in the fuel pressure regulator, I have chased my tail a few times over those even when the fuel pressure was in spec according to a gauge even while the problem was happening. Its good for piece of mind.

[SiFlyBy]

before you fuck with it anymore change the spring in the fuel pressure regulator, I have chased my tail a few times over those even when the fuel pressure was in spec according to a gauge even while the problem was happening. Its good for piece of mind.

Our new TB has adjustable fuel pressure. we were instructed(by the guy who burned the chip) to turn it up to 18 psi. It runs no different at 12 or 18 psi. It now has the stock TB on and runs like fuck just the same.

[highroller54]

cam specs? just for fun what heads?

[t_cel_t]

how much was the 'chip'?

[SiFlyBy]

cam specs? just for fun what heads?

cam is not much heavier than stock. I have the specs at work. I can post em up on monday.

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

[snm95ls]

http://www.dynamicefi.com/

/thread.

[t_cel_t]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

[SiFlyBy]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

trust me, it had crossed my mind. I have the stuff that I need coming for about $150. My buddy has Ostrich and BURN1 for the rest of it.

[Joseph Davis]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

MS1 is utter shit for distributor V8s.

[snm95ls]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

Or something much better that uses the OEM ECU.

Seriously, check out the link I posted.

[t_cel_t]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

MS1 is utter shit for distributor V8s.

how do you figure? i got my car running perfect on a 4 tooth wheel, i assume most v8's have an 8 tooth wheel. not hard to calculated the time between the teeth.

[Joseph Davis]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

MS1 is utter shit for distributor V8s.

how do you figure? i got my car running perfect on a 4 tooth wheel, i assume most v8's have an 8 tooth wheel. not hard to calculated the time between the teeth.

Coil dwell control is an abortion.

[ryan89crx]

how much was the 'chip'?

It was $300 or $350, I dont remenber. I wish I would have known that I could tune it myself for less than half of that. In hindsight, I should have started this thread about 2 months ago but I gues I naively thought that TBI tuning was an almost dead black art. Oh well, live and learn

could of had a MS1V3 for that amount, along with a DIYBOB for the strait hookups.

MS1 is utter shit for distributor V8s.

how do you figure? i got my car running perfect on a 4 tooth wheel, i assume most v8's have an 8 tooth wheel. not hard to calculated the time between the teeth.

Coil dwell control is an abortion.

What would you suggest for v8 EFI coversions?

[Joseph Davis]

94-98.5 Ford MAF is easy for the n00b to implement, requires 36-1 crank and cam sync.  OBD1 GM (7727, 7730, etc - there are some years that are just damn odd so research first) is acceptable for a street car.  I hear great things about OBD2 GM, using some of the late 90s truck ECUs, but have not done anything like that.  You see old DFI's going pretty cheaply, and they are very well equipped for their era and still not too shabby these days.

I hear good things about MS2, but then again I hear good things about MS1.  Your mileage will vary.  You need to research your specific application and take any results with a grain of salt as a lot of DIYers don't want to admit they have problems with something they've done.

Everything else is dollars.

[t_cel_t]

the hei modual controlls the dwell. one wire from the ms is all thats needed. only downside is apon starting the coil only fires after the first tooth has passed( for the modual to figure out the dwell time)

so maybe a tenth of a second it just cranks befor firing

[Joseph Davis]

the hei modual controlls the dwell.

What HEI module?

[random-strike]

pcm4less does really good work. did my lt1 in my corvette

[t_cel_t]

ignition control modual/igniter whatever you want to call it

[PhilStubbs]

in to hear the results on this. i just dropped a 350 into a 1990 silverado that had a 305. some tuning is going to be needed im sure.

[Joseph Davis]

ignition control modual/igniter whatever you want to call it

Let's call it a TFI, and no it doesn't control dwell.

[SiFlyBy]

UPDATE:

we tried tuning last Monday. Results were very mixed. The software was a little touchy as was the hardware. After the tuning experience it was decided to recheck compression. Compression is between 115 and 125. Spec is 150. By the VIN, this truck is supposed to have a 350...by the ECU it is a 305..We ordered heads for a 350 and I am starting to believe that we put 350 heads on a 305, which I am guessing would lower the Comp ratio. Gonna try to find the casting numbers and see if that gets us anywhere.

FUCK

[SiFlyBy]

Cam Specs:

Valve timing         OPEN                 CLOSE
@ .006       INT:   18   BTDC          54      ABDC
                 EXH:   66   BBDC          14      ATDC
 
                            INTAKE             EXHAUST
Duration @ .050      206                       212
Lobe Lift                .2830                   .2930
Lobe Separation       112.0


Just talked to our machine shop guy. He says check cyl leakage as he has seen 3/5 heads brand new that have valves that dont seal worth a shit. Talking to him it seems as if this engine should not really have needed a tune based on what we did. Ill update later with leakage results. leakage is all less than 25%..

[PhilStubbs]

What software were you using? I will be tuning mine very soon and I'm trying to decide how to handle this. This truck will get boosted, but not for 12 months or so

[snm95ls]

UPDATE:

we tried tuning last Monday. Results were very mixed. The software was a little touchy as was the hardware. After the tuning experience it was decided to recheck compression. Compression is between 115 and 125. Spec is 150. By the VIN, this truck is supposed to have a 350...by the ECU it is a 305..We ordered heads for a 350 and I am starting to believe that we put 350 heads on a 305, which I am guessing would lower the Comp ratio. Gonna try to find the casting numbers and see if that gets us anywhere.

FUCK

That ASSumption is correct.

IIRC, the 305 heads of that era were ~58 cc chambers whereas the 350 heads wer in the neighborhood of a 67 cc chamber.