FormulasOnly

OK So I started with a bone stock, worn out but unmolested 1989 Formula 350. It had 180K miles and blew smoke about half the time at start up. It would overheat if not treated right but trudge along mostly reliably. Compression was between 100-120 psi on the easy cylinders to reach. Vacuum leaks everywhere.
So I rebuilt a L31 short block with rebuilt correct L98 350 TPI heads, Howards near stock cam and Vette 10.5:1 pitons. South Bay Fuel Injectors 22lbs, Magnaflow Y Pipe, Converter and Muffler. I just had it waiting for the eventuality of the motor going out... It didn't. The trans went out so I figured change everything at once.
I have it all back together and it drives very nice. It idles nice and smooth. It sounds great.... No SES light. Problem? Its boring as hell, no real punch. Not near the power I was hoping with this much work, and for as worn out as the old motor was....

I had a 1991 Formula 350 a dozen years ago. Bone stock and it would destroy this thing.... Am I just mis remembering?

aliceempire

iTrader: (14)

I'd make sure everything is as it should be. Timing, fuel pressure, cranking compression etc. The factory intake was already holding you back and a retune may help but I'd want to make sure nothing went wrong with the build.

FormulasOnly

Timing Set static with brown wire disconnected at 6 degrees ADV. I'll do the cranking compression today and try to get ahold of a fuel pressure gauge.



I 've had TPI cars before, Vette's and Firebirds... This just really seems to fall short. My 91 TPI Frebird had the 3:08 gears, was bone stock and would light the tires from a stop. This one is 3:23's and pulls away from a stop like a V6 Camry.

Steve Mack

iTrader: (5)

It's kind of to late now.but you should have, and still can put in a higher lift cam.Another easy way to get more power is 1.6 full roller rockers,and port your plenum.Remove the wall in the front of the plenum and open the ports as much as you can.

FormulasOnly

Couple of problems with those options... #1 I'm stuck in California, still gotta get this bugger smogged. #2 I'm not looking for a high RPM screamer, low rpm grunt is more my ballpark.

I've had stock TPI cars before and this isn't measuring up to those standards.

Steve Mack

iTrader: (5)

I don't think either of those options would hurt passing your smog test.But you could talk to a automobile machine shop just to make sure.These changes should help with low and high RPM.

aliceempire

iTrader: (14)

A smog legal-hotter cam would have been choice but what you're describing sounds like a lack of compression or timing error. If the compression is that high, you may be getting knock counts and the ecm is pulling timing.
My tpi is a factory manifold, calculated 10.1:1 compression, a 8-501-8 cam, 3.08 gear, and a five speed and it pulls an easy high 13 quarter. Running ebl so I can constantly look for knock counts. Without premium octane I get a hint of the knocks even with conservative timing.

Fred SS

iTrader: (3)

You said the trans went out. Is it possible the torque converter stall speed is too low? A year before I did my TPI conversion I had a repair shop rebuild my trans. Car pulled from a light allot slower than before. Checked the receipt for the parts they installed. Discovered they put in a torque converter with allot less stall speed than what was suppose to be in my Monte Carlo SS.

1MeanZ

iTrader: (9)

I know your combination seems to be near stock, but I'd have someone look at your tune. The stock tune may not be helping you. I recently got a car that had a mildly built 355 TPI running the stock tune. It was a dog. Now with the correct tune it's an entirely different animal.

FormulasOnly

I might have to look into the tune. Did compression test, 170 psi across the board. Plugs look perfect. As far as the torque convertor.. I've had different stall speeds over the years...I'm not a fan of stall converters. This one by the "seat of my pants" feels stock.
Next is the fuel pressure.

aliceempire

iTrader: (14)

If the plugs look good, I doubt the fuel pressure will show lean. A proper dyno retune will help especially if it shows it's pulling timing. You might be able to check for that if you pull the knock sensor connector off and run it. I'm not a MAF expert but I think I've read you can take that connector off and it won't give a CEL.

FormulasOnly

No load in Neutral the timing advances up to 32ish degrees full advance. I'm solo, timing gun in one hand and hitting the throttle with the other so thats probably give or take 3 degrees...

Orr89RocZ

iTrader: (20)

With est plugged in?

May want to log it to see if anything strange is goin on with the knock sensor and overall state of tune

What cam specs for the replacement cam?

FormulasOnly

Howards 180225-12
Intake Duration at 050 inch Lift: 207
Exhaust Duration at 050 inch Lift: 213
Duration at 050 inch Lift: 207 int./213 exh.
Advertised Intake Duration: 260
Advertised Exhaust Duration: 262
Intake Valve Lift with Factory Rocker Arm Ratio: 0.450 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.465 in.
Valve Lift with Factory Rocker Arm Ratio: 0.450 int./0.465 exh.

I set it at 6 degrees BTDC with EST unplugged my overall advance at 32 was with it all plugged in

Orr89RocZ

iTrader: (20)

That all seems good.

Only guess is wot fueling. Dyno or wideband may tell

aliceempire

iTrader: (14)

I'm inclined to agree. Everything else seems to check out.

FormulasOnly

OK, gotta thank everyone for the input.... I'm thinking I may have had some unrealistic expectations.... Very unofficial 0-60 time of 8 seconds (iPhone timer and an abandoned road)... In Drive. Motor Trends evaluation in 1989 was just under 8 seconds.... So it looks like I achieved "stock".

Orr89RocZ

iTrader: (20)

For a 350 car? I went 6.5 ish i believe with headers.

Does seem alittle slow

FormulasOnly

It feels slow.. I had a bone stock 1991 Formula 350..(N10 Cats being the only difference) It would light the tires from a stop with 3:08 gears, this one is 3:23's and barely squeaks them... I've got access to a dyno in the next couple weeks, that should clear things up... I hope

Orr89RocZ

iTrader: (20)

Where you located?

FormulasOnly

Just north of Los Angeles

ASE doc

Two things that I can think of right off. Knock retard. You can see this on a factory compatible scan tool. If knock retard is coming up, it will drop power. One other thing, is TV cable adjustment. Are you sure you're getting 1st gear kick down? If the cable isn't set tight enough, you may be starting out in 2nd. You can also use a factory scan tool to check fueling. On hard acceleration, O2 voltage should go to 900mV. If it isn't, that likely means that you're not getting enough fuel.

TTOP350

iTrader: (8)

Your car should have dual cats if built after JAN {IIRC}.
The stock auto trans in these cars are very painfully sluggish, esp with a stock size converter.
Something I always did w a stock tune, unplug the knock sensor and bump the timing to 10-14 degs. (run good fuel)
Maybe check your balancer for signs of slippage.

FormulasOnly

I've dealt with regular old HEI and OBD2, Never really messed with OBD1 stuff. If I get ahold of one of the OBD1 readers how with the knock retard show up? Plug it in run it and check the flashes?

Never thought of the harmonic balancer... Looked good but I know that doesn't mean much.

It's a single cat .. I just installed the Magna Flow Y pipe and Converter. It's a single converter car.

Orr89RocZ

iTrader: (20)

If you have a laptop and can buy a 80$ scan cable you can download tunerpro rt. it will datalog everything goin on and you can get an idea whats happening

1MeanZ

iTrader: (9)

He will see if there is knock retard going on, which is a great start, but without a wideband he still won't know whats going on for fuel. I've found stock O2 sensors to be wildly inaccurate when the mixture deviates off stoich very far.

Other questions aside from the tune would be is the cam degreed properly? Was the valve lash adjusted correctly? You said it has vette pistons, was the block decked? How far below deck are the pistons? What is the thickness of the head gasket used? Remember, the vette heads had 58cc chambers and your iron L98 heads should be about 64cc. You may not have near the compression you think you have, especially if you used aftermarket pistons with a thick head gasket and non-decked factory block.

FormulasOnly

OK Gonna show a little ignorance... Got the program... Where do I find the "Scan Cable"

The cam was degreed withe a straight edge, used the late model Gen1 Edelbrock timing chain. Head gaskets were the FelPro regulars. I guess when I said Vette pistons.. I should have just said 10.5 : 1 Sealed Power forged listed them as 10.5:1 with the 64cc Heads at .030 bore.

One more addition... 2nd tank of gas through it 18mpg combo city / freeway.

Orr89RocZ

iTrader: (20)

Moates.net

ASE doc

10.5:1 is pretty aggressive with cast iron heads. Generally no more than 9.5 with iron on pump gas. 10.5 is aluminum territory, and that requires a well designed chamber with tight quench. You'll want to be careful with timing. I wouldn't be surprised if your getting knock retard.

1MeanZ

iTrader: (9)

This is exactly what I thought, I'm in 100% agreement.

If the block wasn't 0 decked with the pistons, and if he's running the fat felpro blues, his quench may not be tight enough, which will exacerbate the condition he has with lots of compression and iron heads. I'd say it's a comfortable bet that there's some timing retard happening, especially with that mild cam.

Street Lethal

iTrader: (16)

Just reading through the thread and am curious, you say it is essentially built like a stock L98, so not sure what you're expecting. It is essentially a stock rebuild with increased compression and stock chip. The transmission you replaced, what was it? Did you reuse the stock converter, or did the replacement transmission come with another one? Are you sure its' detent is correct? Did you foot brake it to see approximately when the converter is coupling? What do the spark plugs look like, are they showing any signs of detonation, rich, lean, etc? A full point increase in static compression can yield anywhere between a 2 to 4% increase in power, do you at least have an adjustable fuel pressure regulator to compensate for it if you cannot increase your fuel tables via tuning?

BadSS

Couple of basics. As other have said making a scan to see if you're running into a knock retard on the timing is crucial to rule that out. If the new converter is really tight like most rebuilds come with (brake stall speed around 1200 - 1400) could easily explain why it won't spin the tires compared to the 1800 - 2000 stall speed that comes in these stock.

Diving deeper in the basics, did you use the stock timing tab and balancer? If so, unless the balance has spun (they can and do) or the crank key on the new crank is "off" (which they can be a few degrees) you should have a decent "zero" or TDC reference mark.

If you used another cover and an aftermarket timing tab, unless the engine was set with a degree wheel to TDC and then the new timing tab adjusted to read "zero". There's no way for you know for sure what the "real" timing is. I saw this all the time when I used to do power tunes for folks. I can't tell you how many times I saw the tab off - way high and low. When you're faced with that type scenario, you have to give the engine what it wants. Meaning it might show 40+ degrees with the inaccurate timing tab yet giving you no knock -so you add even more. OR,, it might show 26 degrees and you're about to beat down the top ring land - so you pull timing. I used to tell folks about it, but found it much easier to not say anything, give the engine the timing it wanted, and then just move the pointer to my best guess of what the "real" timing was.

Saying all that, I'd definitely suggest you get a scan tool, see if there's knock showing or not and adjust the timing up or down accordingly.

FormulasOnly

OK ... I'm gonna go with the tighter Torque converter idea and my Rose Colored glasses looking back at my old TPI Formula 350... for part of the problem
I'm not showing any codes for detonation... I did use the stock timing cover and unfortunately the original 190K mile Harmonic balancer(I'm going to swap that for new). Once I get the new one installed I'll advance it up a bit and see if that gets me anything.
I can't say how nice it runs..absolutely beautiful.... just boring

I just shredded the new Transmission mount ... So apparently I'm making some power

anesthes

iTrader: (12)

Nothing wrong with 10.5:1 on iron heads as long as he has the right cam for that compression ratio.

Aftermarket cam, higher compression ratio, no tuning. Lucky it drives at all.

-- Joe

FormulasOnly

It's a next to stock cam and only 170 PSI on advertised 10.5:1 pistons... So probably closer to 9.75:1. The plugs look perfect. The car drives perfect... Just perfectly boring.

I remember the days of OBD1 chip tuning and they aren't good memories... Granted they were from the 5.0 Mustangs. I had a 89 stock computer ... Couple buddies had a 88s and 90s with a crazy promise everything chips ... The got 9 mpg vs my 27mpg. It would barely idle, failed smog and generally drove like ^$%$. But hey they would beat me at LACR by 2/10 of a second ...... So I'm a little leery of the PROM chips.

anesthes

iTrader: (12)

"advertised" ?? You didn't measure your assembly ?

Prom tuning sucks, but you don't have much of a choice. You need to tune it.

These cars are boring stock, and even slightly modified. What are they, 240hp ?

Drive an LG4 and you'll feel like you are going backwards.

-- Joe

1MeanZ

iTrader: (9)

PROM tuning is not scary and you shouldn't fear it. Your bad experience was likely a result of ignorance and poor attention to detail. Learn to do it yourself or find someone competent to do it. There are lots of guys on her that have been running custom PROMs for well over 15yrs now, I've been doing it for 9. It's possible to get good mileage with good performance with custom tuning. The key is finding the right person to do it.

TTOP350

iTrader: (8)

Sounds like I need to bring my junk up your way for a little tuning.

1MeanZ

iTrader: (9)

I assume you mean your black '89 Formula, I'd be honored to work with that car. Don't hesitate to pm or e-mail me any time.

TTOP350

iTrader: (8)

Wow, thanks..
Have some things I'm working on and we'll see when I get it done..

Kevin91Z

iTrader: (1)

Dyno Don and I are in Orange County just south of you, and we have scan tools and PROM equipment. Are you willing to bring the car to us some Saturday in the future? Don is there every day but I'm only there on Saturdays.

SoCal TPI
2831 E. White Star Ave #A
Anaheim, CA 92806
714-630-1502

1MeanZ

iTrader: (9)

To the OP. If you don't take this man up on his offer you will be making a huge mistake...

FormulasOnly

Well I've hit another road block... She left me stranded one night... my first time in 27 years I've gone home on a tow truck... Changed the fuel pump and it ran again. For awhile... It started coughing at low throttle but not dying ... Then all of a sudden it had all the power I remember the TPI cars having... The car kicked sideways on me and turned the rear tires to smoke.... That lasted about 5 miles.
Now I've done all the troubleshooting and I'm not getting fuel.... I've got pressure 40psi.. but it only runs on starter fluid... I ordered the NOID light to see if the injectors are being triggered....
Any ideas?

aliceempire

iTrader: (14)

I don't know what "all the troubleshooting" includes but if the injector pulse is there I'd look into bad injectors? bad regulator? weak spark?

jmd

iTrader: (4)

Hope you get things figured out easily.

Thoughts as I read through the thread:

You don't need a super-close to stock cam to pass smog.
And a converter matters a LOT in the "fun drivability" department.

Good luck with it.

FormulasOnly

Well it looks like I had a screwy ECM. I got a new one and she fired right up.. ran rough for a couple minutes, then smoothed out and is running beautiful......

peterc005

Any more details?

FormulasOnly

By the seat of the pants it feels like its got the power it should. Only driven it 20 miles or so since the ECM swap, so I don't have a good idea of mileage.

mrestrictrplate

iTrader: (2)

go to those guys and let them check the car out anyway. It can only help to have a trained eye make sure everything else is ok, plus some free mods in sure they will do for you.

FormulasOnly

[QUOTE=1MeanZ;5968153]He will see if there is knock retard going on, which is a great start, but without a wideband he still won't know whats going on for fuel. I've found stock O2 sensors to be wildly inaccurate when the mixture deviates off stoich very far.

I was getting wild variances in the O2 readings 40-900 and never stabilizing .... under any condition. Anything past 1/2 throttle I'm getting a lot of knock counts 20-30 in a matter of 10 seconds... and its showing 8-10 degrees of retard....

I'm swapping out the CarQuest Bosh O2 sensor for an AC Delco one and I'll data log it again....