I just had local mechanic finish puting the engine together but he cant get it to idle and says it runs too rich to the point where it just burns the plugs... i had previously added BBK TB ported runners and lover intake and bigger injectors on the stock motor and ran fine...now i bough aluminum edelbrock heads, comp cam (512 lift), headers, roller rockers and after all installed car just worse than i had it before....meck sais he cant adjust timing till exhoust done so i had exhoust connected he still struggling...i,ve replaced timing chain(original) cap and rotor, spark plugs and wires,o2 sensor, cooling temp sensor,and installed AFPR...i dont know what could be wrong, mechanic seemed puzzled to me too altough he keeps on telling me not to worry but has my car for over 2 weeks and keep checking everything possible to the point he took the comp. out and cleaned the connections on it (which i dont think it has anyhting to do with it) the AFPR and injectors are from 406ci i had before as well as the ported BBK TBI and runners but i dont see how that could be the prob since stock motor ran with those parts(except AFPR, i had it installed with cam and heads) mechanic now saying inject. too big (after i told him they were from 406) i know its not the case...i dont know what else could be wrong....any tip would help....thanks

 

dont expect a stock L98 ECM to work with a 406 and upgrade cam/heads/intake.

you need a chip tuned to work for it. nothing else you can do

 

what are the specs of the cam, and what # are the injectors?

did he check what the fuel pressure is at? it could be a bad afpr and have the fuel pressure at whatever is comming right from the pump

sounds like either the afpr is bad, or he doesnt know what he is doing and has the fuel pressure really high.

 

i was told i will need to burn a chip to run corrrectly just wasnt sure that car wouldnt even stay idled w/o it...and the block is 350 L98 i had some complications with 406 end up junkin it :/ but...injectors that i took off 406 dont have any #s on them at least i couldnt find any just red in color but again before head/cam install i used those injectors on stock L98 and no prob besides that i noticed more gas burning and did choke on me few times but nothing serious...as for AFPR it might be set too high since it was previously on 406ci...mechanic was surprised that i told him AFPR could be controlled and pressure could be lowered from its position(i thought he would figure doing what he does i mean that was the reason i replaces stock with adjustable) i dont think AFPR is bad although it might be set too high,since 406 it was on ran fine before removed from the car, im not exacly sure what pressure it was reading for him he just said it was too high...i know hes trying to do his best to figure out what could be the couse but if he doesnt know what hes doing i d rather him not going through things that dont need to be touched....from $600 job end up over $2500(not including heads/cam/headers) and now his blaming the injectors that i ran stock motor with(wish i knew the #s on them)...im confused...that was the main reason i took the car to someone who apparently knew what they were doing and not get into it again myself...unfortunately even paying some for the job end up in the same situation that i prob would if done on myown...well im going to give him another day and im gonna pick the car up before it get worse :/ i already replaced everything possible and almost everything is new...combination i went with was matched by perf shop (NATIONALS here in miami) i'll dbl check on the AFPR and then hope the chip is my main couse of this whole thing, BTW the specs on the cam -valve lift .510/.540 duration@0.50 229/245 lobe separation 112.0....thanks for the replys

 

You'll really need to find out what size those injectors are.

Chip
Chip
Chip
Chip

Nearly identical issues as me after my engine build. It was the chip.

 

thnx i'll pick up my car today before anymore damage done by confused mechanic (which i was told knew what hes doing) ....and burn a chip....as for the injectors i dont know the way to find out what size they are since i couldnt find any markings on it at all...is there a way?...

 

No numbers at all???
I'm lost.

Do you datalog or have someone around you that can?

 

Also, that cam looks a tad on the big side for TPI. 229/245 at .050? I think that is a bit large. Any others may want to jump in here to express their opinions. And it may be a good idea to find out injector size as well, not just ballpark guess. I've had similar experiences, you have to get a prom burned. ALSO, don't be afriad to find another mechanic. Don't feel bad you may offend your's, he may be in over his head. I've had this problem as well in the past. Go find the knowledgeable help.

 

If these http://www.fiveomotorsport.com/Parts...50945-F1SE.jpg are the injectors you're running, they are rated at 30lb.

 

yeah from what ive seen, that camshaft is quite on the large side... i never really see anyone run over 230* duration @ .050 on a TPI

secondly, get your car away from that mechanic as fast as you can if its not already away from him. he didnt know that you can adjust a "adjustable fuel pressure regulator"????? wtf

get a fuel pressure guage, hook it up on the fuel rail, take off the dizzy cover and adjust the screw on the afpr (turning in or out) and set the fuel pressure @ 38psi to start (should be in mid-high 30's at idle, 42-45ish @ wot)

also, make sure the timing is set correctly, that the TPS voltage is where it should be at, and that the IAC is working properly.

 

i knew the cam is huge...its the biggest one from compcams that is shown in tech article/camshaft for 350 stock roller...but according what i was told it should be fine....it suz if they were wrong TPeye thnx for the pic it looks just like that but i see some #s on that 1 but on mine its clean for some reason...and how is it possible for stock motor without heads and cam run on those injectors and after upgrade it becomes a question...i would put my old orig injectors on but i think i threw them away when i was moving...and as for the mechanic....it does look like hes lost and not sure what to do anymore....i'll have the car home today try to adjust AFPR myself and replace the fuel pressure gauge (the one i currently have dont think it read right) after all the money i put into this looks like im going to have to spend some more to get back to life....thanks

 

so wait, is this on a 350 or a 406??

that cam is perfect for a 406 but abit big for a 350 but it still works if tuned right. the specs seem to be like the CC306 if i'm not mistaken which is actually 230/244. if its a comp cam then i do believe you have a CC306. thats big for TPI but will work if tuned right. it really needs a HSR or miniram tho

that cam is making the car run all over the place, you need a tune for those injectors and cam. thats all there is to it.

try a mail order tune if you cant get your own to work. they can get you close. fill out the spec sheet orderforms they provide and they will get you started

 

Mine's only 224/230 and it's not fun to tune.

 

which car is it in, the MAF car or SD car you have

 

The SD. In fact i'm tuning right now. 4 mile blasts down country roads.

 

its on 350 L98 GTA TPI ...here is the cam specs
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Eww.... are those..... flow tech headers?

If they are, throw them away now, before you feel the wrath of poor craftsmanship later.

 

yeah i know i realized that lil too late....my budget is low right now specially with all the money put into the motor and labor...its better than stock headers so i'll have em replaced as soon as i get some more $...thnx

 

yep the 306 cam! lol likes to rev, abit much for TPI but its possible to get it running...just gonna require a TON of tuning time

 

yeah...looks like i got myself into some S*** lol but hope it'll all be worth it...good thing im runing on TH350 w/3000stall...

 

i'd just buy a HSR now and tune for that, you'll make much better power that way and it actualy be worth the trouble with tunning.

 

sounds like a great way to go but cant afford it right now..if i put any more money into the car i think i could of bought a GTA aslready running with mods for half the amount i already put into it lol....i just got a call back from mechanic(i dontknow where he was hiding allday) but he claims car is done and he took care of the problms(doesnt burn alot of fuel and got it to idle somewhat)...i think he took the advise on the AFPR lol...im hoping for the best...thnx for all of your help! now i need to to get into burning a prom for it...and see how it runs...hopefully with all the mods it'll push 300hp

 

didnt have a problem with mine....just a crappy transmission and 2.5 inch exhaust caused my problems haha
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a 350 with the cam i think it is (same cam i am running) with a decent set of heads will make about 300 to the wheels, give or take a few of course

 

thnx i was thinking somewhere around there....300 is better than 190rwhp orig so i'd be happy w/the change..... but its never enough so its just the BEGINING

 

i'd actually expect alot more power with that cam. LT1's make 350-360whp. A L98 will do 330 more than likely with a good intake. stock TPI tho i can see just a tad over 300whp. TPI is killing it off bad. but it willl make torque.

EDIT: i see you have edelbrock heads now? is this correct. heads/cam could add more power but TPI is really choking it now.

 

yeah i was hoping for more too...i just got the car back mechanic got it to idle but still burning alot of gas...i drove it back home but didnt see much difference with new Edelbrock aluminum performer heads/CC306 cam w/1.6 alum. RR and headers...it drove just like that before mods were added...i hope burning a chip will make some diff cuz all the $ put into this wouldnt be worht it, ...if TPI aint good should i go carb and it will make a diff? i was told TPI runs better than carb thats why i left it...anyhow here are some pics of the engine
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well if its putting out the same amout of power as a stock L98 with that crazy cam, big injectors etc then youll be doing pretty good once you get it tuned.


but, good luck finding someone to do it for you... youll most likely end up having to try to do it yourself if you want to actually get somewhere

 

I know there is alot of debate on the topic of carb vs TPI, my opinion on that is a carb will make more power, but in this day and age (environment, gas prices, etc, etc) if your going to drive it on todays roads daily, yes stay TPI. It makes nice power down low for street driving (torque) and you'll have much better fuel econemy and efficiency than with a carb. And with that statement, let me say that is with the TPI "TUNED"!!!! So yes, to me TPI is better to live with everyday, reliable, etc, but go get it TUNED.

 

yeah but all the stuff that he has put on that l98, he will have to spend some time and money in getting it tuned... he doesnt even know what # injectors are on there so thats going to make it just that much harder

 

yeah im going to work on tunnung it myself untill i loose my patience lol...and the weird part is that many told me that TPI would actually run harder(more power) than CARB thats why i stayed with TPI cuz i have a DEMON carb that i could of used for this set up....im NOT worrying about gas prices at all...i used to spend close to $90 a week and if i go out somewhere furhter its even more $...i just have a heavy foot lol so im used to burning gas...so im going to do some research and see if i can actually get more power from carb then maybe make the change...also just wondering i have the whole custom ECM from 406ci that had most of the parts that im running on now...is it anyway possible if i can connect that comp to my car and see how it runs? or just the chip it self
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as for the injectors....i dont know who the heck made them but there is no #s what so ever on either one of them...they did came off a 406 engine that i had, they red in color(which doesnt help much) and thats about all info i have on them

 

you will loose the flat torque curve from the tpi, but with a carb you will pick up well over 50rwhp... you also will never have to worry about having someone tune the computer for changes in the motor.

but you will lose reliability of efi... its a win/lose situation either way you go, it all depends upon what you are willing to sacrafice in the end

 

i just took the car for a ride...it actually runs better than i thought but i still got to burn a prom chip and then i hope its going to be even better after tuning it...it sounds crazy specialy that CC306 through the 3in exh in fact i think its too loud for street...COPS magnet :/ but at least i got it to stay on runing with alll those mods...from first to second on TH350 it kicks and peels out and another good kick to the third...thnx for all the help and helpful info

 

actually TPI has no flat torque curve at all...its very peaky. Carbed manifolds or HSR/miniram with short runners make flat torque curves

 

Not flat?
Check out my DD2K for my 92.

https://www.thirdgen.org/forums/tran...different.html

 

thats a simulator. go dyno it and you'll see LTR TPI dont make that flat of a torque curve. i know mine didnt

 

i been trying to get the # on the injectors but couldnt come up with anything so i decided to go back to orig 22lb since these flooding the cylin, i was just wondering if i wont have any problems runing on orig 22lb injectors with that cam and heads, maybe if i could adjust AFPR in addition if necessary it'll be fine??

 

Might call the guy at PCMFORLESS. he pulled a calculated 26 hp out of my L98 :shrug:. $.02

 

22lbs wont be enough to feed that cam. i dont think that is. 24's are needed for sure.

you'll need to have the chip set for the injectors that your using. since you dont tune yourself or have anyone else that can, might as well try pcmforless or some other online chip service. give them the details of the combo, and i mean all the details.

 

Go back to your stock injectors, turn up the fuel pressure to around 45psi at idle, unplug your EST connector and set your base timing up. You're probably running pig rich and lazy on timing. The injectors will work for now and will keep you from flooding the cylinder bores. If the car doesn't like the 10 degrees base timing go down to 8. You need more timing with the larger cam. If these mods don't help then you're absolutly going to have to burn a chip for the car. It's better to have a little to small of an injector than to stick big injectors in and just hope the other mods you did to the engine compensate.

 

you absolutely right....so im junking the ones i have (since no info was found about them besides that they BOSCH and red in color which doesnt tell me much even with a search) and buying 26lb accel and prob send my ECM to PCMfor less and let them set up the mods

 

If they're Bosch red tops they're 30 pounders, don't throw them away they have value, just take them out for now. Do you need a set of stock 21 pounders? Or can you track down your old ones? I would avoid the Accel injectors and instead opt for a set of LS1 style injectors. They come in different rates just keep in mind they're rated at 4 bar (about 60 pounds) instead of 3 (45 pounds). Even stock older LS1 injectors are 28 pound at 4 bar and they'll fit with very little work.

 

FINALLY..before removing unknown injectors...i barely intouch with a guy that sold me the 406 and he told me those are BOSCH 30lb injectors looks like FORD Motorsport part #0280150756 it seems like there 2 part #s to it one of them is the same pic TPeye showed earlier but end on 945...but this saved me some time and $ ..i already submitted the application with PCMforless just got to send my ECM to them for tuning...its going to run something over $200

 

After which you will regret spending that money and wish you had just got into prom tuning on your own. I would invest in tuning equipment and in the meantime try adding some timing and going back to stock injectors. That way if something else is wrong you can isolate it and have it fixed while you start making a good tune for your current setup. To save you the time and hassle I will put a generally close tune onto a chip for FREE just pay for the prom chips but you should definetly get into tuning these things on your own.

 

actually, i have had my tpi on a live dyno and the torque never varied more than 10ft/lbs all the way acroos the board from the time they started testing(2000 rpm) till the rev limiter.

 

did you have some sort of siamesed system? because most TPI systems dyno with a peaky torque curve and NOT flat. Thats why when you upgrade to a miniram/lt1 or HSR you lose peak torque but gain a flat torque curve.

 

the only thing siamesed are the plenum ports....not much of a difference. i have edlebrock runners and the intake is portmatched to it. the heads have been opened some(gasket matched) and bigger valves out in. 52mm throttle body and k&n's in a factory tpi air cleaner housing for camaros.

 

Jeff you have to be kidding me you also have a 91 with an 87 engine? small world. If you're TPI is displaying a flat torque curve you probably have a restriction somewhere. Did you change the cam or anything when you built the engine? Generally a TPI reinforces torque in the mid range around 3500 to 4000rpm and you'll get a bump there. You could definetly make a TPI have a flat torque curve but that's not doing what it wants to do.

 

yeah, the cam specs are in my sig. i had some porting work done to it but not much more than gasket matching. from 2000rpm up it never varied from 325ft/lbs to 335ft/lbs. wish i still had the dyno sheet. im wanting to do a cam swap in the near future(winter project) because the horse power was only around 250(max). the horsepower did have an arch though. still trying to figure it out.




the power train was donated from my previous iroc.