I need some help from you guys that are used to dealing with these computer controlled cars. I have raced NHRA for 14 years but I know nothing about this. I have a 1989 Formula 350 w/crane cam kit, forged pistons, aftermarket rods,headers and 3" exhaust, no cats, Edlebrock 58MM TB, TPS Mini-Ram, Holley 260 pump and adj regulator, MSD 6, 2400 stall TCI with Moser complete 12 bolt 3:73. All this ran real well until I added the MiniRam. Now when I first crank it, it idles good for a minute, then starts idling very poorly. When I hit the gas, it pops. MY guess is a lean pop. I still have the stock chip because Paxton recommended it to keep the timing from advancing. TPI says they're not sure what I need. At first they were going to send me a chip (575.00) then after I sent them all the info, they said they were not sure a chip would help. Another tech there told me that he didn't think the MAF would work with the MiniRam and Supercharger. Too much air he said. May have to switch to Speed Density (which tells me nothing). I need to get with someone or some company that can help me work all this out. I went from a car that was fun to drive to one that I can't drive. I have looked into burning my own chip but I might as well be looking at the plans for the space shuttle. I have never messed with ANY of the computer cars so it's all french to me. Can anybody help me? Jimmy

 

Considering how mild your modifications are, it doesnt sound severe enough of a combo to not be able to atleast drive around and have decent power without a chip. Sure a chip could be nice for opimizing but it should run fine especially with the MAF. If I had to guess I would say it could be timing related to distributor install. The other more likely problem would be a vacuum leak. new manifolds can have vacuum fittings where we didn't expect them to be, and they end up not plugged off. removing and re-installing intakes can cause us to crack old lines brittle plastic or rubber lines causing mystery leaks. or have intake gasket mismatch/mistourque/mis-seal problems. MAF cars are very critical of vacuum leaks and usually respond by starting well and then running rough, causing a pop or little series of pops in the intake when the throttle is moved. Driving it around a bit can cause a code to pop up (lean engine) and the service engine light to come on if it doesnt already, or looking at the data stream on a scan tool will usually show the lean condition.

 

I'm with Tom. Having dropped a Miniram onto an otherwise stock TPI motor I can tell you it made absolutely no difference in the idle or very light throttle. When you got into it you could tell that the radically shorter runners of the intake had moved the torque curve around quite a bit, but the idle was exactly as before.

Possible exceptions, although I doubt either of them apply to this situation:

1. Older 85-87-ish TPIs that used a cold-start 9th injector. However, they will usually run lean/rough right from the get-go without the cold start injector helping out. Doubt it's your problem.

2. Also, your stock chip is expecting to see a functional EGR valve there, which your Miniram doesn't have. The chip can not actually tell that the valve isn't there, it only DIRECTLY knows that the EGR vacuum solenoid is still under control of the ECM (a little solenoid in-line on the vacuum line that used to go to the EGR valve). It may, in some cases, be able to DEDUCE that the EGR valve has been defeated by looking at other sensors, but usually only after a few miles of highway running at steady speed (where it will throw a Check Engine light). I doubt, however, that this could ever possibly have any effect on a cold-start idle since the EGR doesn't come on-line at dead-idle ever, and only at part throttle after the engine warms up a little.

 

the EGR does have a function sensor but if you dont put the car in gear it would have no bearing. For example, if you started it in park and waited a second and it started running rough and you tipped into the throotle and it popped and the whole time it was in park, then it wouldnt be any emmisions equipment, if you experiment a bit and find that the car doesnt screw up until the car see's that it is in other than park then maybe it could certainly be an emmisions issue but I doubt it. If it is an emmisions issue sometimes you can just make the ECM see the tranny is still in P-N by making the switch stay in the P-N position after removing it from the shifter tower. this can cause a VSS code because of the ECM seeing vehicle speed in Park-Neutral. Remember none of this is a problem with the P-N switch, it would be an emmisions problem (if in case thats what it is) leaving it in P-N just causes the computer to not pay attention to the emmisions.

 

I'm going to recheck for a vacuum leak. I can drive the car around, but when I give it gas, it stalls until I either give it more gas or let off some, then it catches back up. I drove it about 40 miles lik this. Yes, the check engine light is now on. My snap-on scanner is supposed to be back today and I will scan it. Thanks for the replys.

 

the code will be a 02 sensor for engine lean after the ECM has placed all the extra fuel into the engine it can internally and the O2 is still showing lean.

 

My guess is it could be a bad MAF sensor IF it's not a vaccum leak. It is possible it could have gotten damaged, or broken. I belive if you disconnect it, the computer will go into "limp" mode,... and although it will not run optimally, you will be able to see if the Mass Air Flow was bad. If the MAF was bad, it'll run much better with it disconnected. If this is the case, get one used, it's much chaper in our classifieds section. BTW the idoits at those companys are both feeding you a bunch of BS , they don't know the first thing about our cars. they are just salesmen, not really techs. I've never had any good advice from them,... only left field stuff. Don't listed to them. Good luc, try this first, if it's not the cause, then the vaccum leak is probably it,.. but testing the MAF is MUCH easier.

 

Thanks again. I agree with you. I don't think they have a clue as to why my car is now running this bad. I've raced Super Gas (9.90 at 160mph) for 14 years with a 588 BBC on alcohol and an electric pump (which is the hard way) so I'm used to tuning and working on fast stuff. I can tellwhen I talk to them that they're as lost as I am. TPI told me to call Paxton for a boost controlled fuel regulator. Paxton didn't see how that would help and told me to call Jegs. JEGS??? For technical support?? I told them I use Jegs for some of my racing stuff but never for technical help. Paxtonassured me Jegs coul help me. Of course, Jegs informed me they just sell parts. I ALREADY KNEW THAT. They told me to call Vortech. I died while wating for them to come to the phone. I can tell I'm on my own. I've thought about taking the S /C off and switching to nitrous. At least I would know something about it then. I can tell I'm on my own and my only hope is probably going to come thru this webite. Thanks again. JimmyDaniel

 

yeah, this site is the best place, there are some guys on here that really know these cars. they may even need more info, but what we've said is a good start. and btw you're right jegs is definately poor tech support, but i think those other companies are even worse than jegs,.. lol...i learned a long time ago when i called LPE 4 differnet times, and got 4 totally different diagnosis. LPE is supposed to be so good, but you'll never talk to those guys that really know their stuff. Youu just get sales guys. anyway, i wonder what LPE is doing now that ligenfelter is dead? hmmn

 

Once you have figured out your problem, you may want to investigate switching to a 730/749 ECM with Syclone/Typhoon ($58) code.

Do a search for 749, $58 or SyTy.

Just took my Malibu for testing... and it passed with flying colors.

 

The problem is a lean backfire at initial throttle opening. Almost ALL of us MiniRam guys get it. The supercharged MiniRam guys tend to get it worse. You need to increase the pumpshot (accelerator pump tables) in the chip. It's a 5 minute change. THIS FURTHER EXPLAINS THAT THE PEOPLE WHO YOU TALKED TO HAVE NO FRUCKING CLUE WHAT THEY ARE DOING. $575 FOR A 5 MINUTE CHANGE?!?!? Hahahahaha - I can't believe what they told you about the MAF, supercharger, and MiniRam. They are clueless. Yes, you can get this combo to work. You just need to know how to tune the chip.

Tim

 

Thats TPIS for ya...dont get me wrong, the intake is bad ***, but they are a little too stuck up on the pricing they have been raping us for years over a very simple and cheap to produce product. If/when the new shorter version of the HSR comes out as some are discussing already then they will be forced to reduce the amount of rape they do to the consumers. Then they will have to face the change in the realities, of the same economic situation they have been benefiting from for years.

 

Hey, i told you some of these guys know their ****! Stick with it!

 

Since I know for a fact that I cannot make a chip, who can I get to make one? THANKS for all your responses. Jimmy

 

One more thing. When I floor it and take it all the way thru the gears, it's not ANY faster with the MiniRam than it was before.

 

Are you using the FMU? The stock chip is why you aren't feeling anything. Without finding someone close to you who burns chips, you are at the mercy of the mail-order tuners.

 

I am not using an FMU. In fact, I have no idea what an FMU is. TPS says now with their 27 lb injectors (550.00) and chip (575.00) it will probably be ok. @#$%^&&**()) I thought that before I put the miniram on.

 

ROFLMFAO - $1125 for a chip and injectors. That's a bunch of crap. First - never pay that much for injectors. SVO 30lb injectors for $300 (actually 33lb injectors) will work fine. For a custom chip you might want to try working with Ed Wright at fastchips.com. HOWEVER - what you really need is something that is NOT mail-order. Even fastchips.com would have to revise that calibration several times (with data that you provide them) in order to come close to a HALFWAY good calibration. Mail-Order chips will give you an endless headache. What you REALLY need is somebody who knows what they are doing to actually be there WITH YOU AND YOUR CAR to work on your car. That's what you need. You've payed thousands of dollars in mods. The problem isn't the mods - it's the calibration ... now you need a good calibration to make it all work.

Tim

 

Tim, I was told you were the guy to talk to. I just didn't know how to reachyou. Everybody on here has been real helpful, unfortunatly, I know so LITTLE about these computer controlled cars that I'm not much help. ALL of my tuning knowledge is in Top Sportsman, Super Gas, 60's muscle cars and that sort of thing. Number1, where can I get those SVO injectors? And second, I don't anyone in my area to help me with a chip. I know I need one butI'm afraid it would take me forever to learn enough to make my own. I don't mind at all spending the money on the stuff to do it, I just don't know if I would ever get it righ with my very limited computer knowledge. WhenI read these eprom post, I hve NO clue what these people ar talking about. Codes, eproms, 749's, I might as well be wrking on the space shuttle. Do yo know somebody that can make me a chip and get me as close as possible? Thanks for anything you can do. Jimmy Daniel

 

Jim,

Sorry man. I don't know anyone in Alabama. I wish I could help but you are too far away for me to be of any help. Be VERY careful about mail ordering a chip. It's not as easy as giving your specs to somebody and having them program a new chip for you. They need the proper data to know how and what to change for the fueling.

Tim

 

Thanks for trying. Anybody else out here close to Alabama or know somebody reliable in this area? I'm still on square one.

 

A possible temporary solution might be a FMU until you can get the chip, also running that baby that lean (no extra fuel for the boost will eventually result in damage. the engine has no way to tell you are gettting way more air in than it would be without the blower. a chip will be the way. if you have gotten a chip you may want to consider telling them to re-burn it for the blower.

 

well, it might take some time to educate yourself on how to do your own chip, but you can do it. as long as you understand what an engine needs, that the whole goal is to spray fuel and ignite sparks, it will all come to make sense. you don't have to be a computer genious or know how to write computer progrmaming code.

in the specific situation above, let's go with what traxion said, that you are lean on initial throttle opening. if you had a holley, you'd dig out your little plastic cams and find a bigger one, or maybe try a different squirter. but this is no holly.

the computer your car is using constantly recalculates a variable (number) called LV8. It is, roughly, the "load" on the engine. This number goes from 0 (no load) to 255 (high load). As luck would have it, in the computer, there is a table (just think of it as a grid) that helps control how big of a pump shot you get, based on engine load (LV8). for low load, you get a small pump shot. for high load, you get more.

Changing the value (size) of the pump shot is pretty easy. You just open the "tunercat" software, go to the "tables" menu, and choose "LV8 Accel. Enrich. Factor vs. Delta LV8". Yes, there is a lot of abbreviations there, but what it means in english: "a grid which relates acceleration enrichment to engine load". When you choose this table, up pops a table that is 1 column wide and 5 rows long. They look something like this:

LV8 Counts - Multiplier
0 - 0.13
64 -0.13
128 - 0.16
192 - 0.20
256 - 0.20

Based on just those five values alone, the computer can estimate the pump shot needed for any LV8 (load) value. Now lets say you wanted to get a little more pump shot. you'd change it to look something like this:

LV8 Counts - Multiplier
0 - 0.15
64 -0.15
128 - 0.18
192 - 0.24
256 - 0.24

Then, you'd save the changes to file, open up the "pocket programmer" software, pop a chip into the progrtammer, load the file you just saved, and burn it, then test drive. voila. that's it!

I'm getting pretty off topic for the forum we're in here so i should probably stop now. when you have some time, start reading the stuff in DIY PROM, and get familiar with the basics (the differences between 165 (MAF) and 730 (SD) for example)...and the software and hardware you need. it can be done!!

*disclaimers:
1) i've never tuned the acceleration enrichment on a 165 (MAF) car, as I own a 730 (SD) car
2) there are actually several tables that control pump shot (acceleration enrichment), this is just one. for example, there is another that lets you control it by temperature - such as if you need more pump shot cold, and less hot (try that with a holley)!
3) the previous recommendation for $58 / 749 SyTy is a good one! Gm's Syclone and Typhoon trucks gave us a pretty versatile computer to work with for boosted applications such as yours. The last 3 digits of the computers part number is 749 (that's why its called a 749), $58 indicates what "code" runs on the computer. This is a computer that was born to understand boost, and make it work for you, not against you!
4) There might be some SyTy or turbo buick forums out there with tons of info on the 749....

 

91L98Z28,
That was a good post. I am in the process of getting the stuff together to convert to the 749 ECM. The guys like yourself on this website have been a big help. I appreciate all of it. Keep the information coming, I'm still learning. Your last post was helpful in explaining how to use the programs. Jimmy

 

I had the exact same problem with my car. Supposedly the previous owner told me that the car ran well with the stock TPI intake, but after he switched to a miniram it had problems. I knew I wsan't gettingany fuel compensation at boost because of the stock computer and lack of FMU so I decided to switch to a holley commander 950. All the problems went away after that.