hi guys,
how are ya all.
well i finally got my vette back from the dyno tuners after a 6 week bloody wait!!
a bit of history for you,
it is a 1991 l98 motor,6 speed with 1/3/4" long headers,high flow cats,x-pipe,true duel 2.5 " mandrel bend pipes back to magna flow rear mufflers.
well i fitted a 8 throttle indvidual runner cross ram intake manifold and a Hlatech after amrket fully adjustable programble ecm computer that runs the engine only side of things!
after getting all the wirng sorted out the thing fianlly runs now,horay.
it is running 30 pound ford motor sport injectors that have been full serviced ect.
currently it is a standard cam and heads
ok now the bad news,
after about 10 mins , the headers starts to glow hot bright red !!!!
now mainly the middle and back pipes glow red!!
what could this be ??
he has set all the fuel and igntion timing pages set up ok i beleive and is familar with haltech systems and he told me he set the aeromotive fuel regulator @30 psi
when i tried to run this 8 t/b before with the standard ac delco it was running really shit,rough and crap.
im thinking that i might of stuffed up the fairly new cats that i have as there was too much unburnt fuel getting thru down the exhausts.

do you think if the cats are now stuffed as in blocked up,the heat from the engine cant escape back thru the exhausts oulets and it is builing up and the headers are heating up.

or could it be one of the following,
1/ timing retarted ?,
2/a/f ratio mixture is burning in the exhaust ?,
3/vaccum leak ?
4/too rich or lean ?
5/late timing ?
6/plugged exhaust,cat ?

what do you think guys please ??
can any one please help advise me ??
i have just spent $ 1,800 Aus getting this darn thing tuned and now have the exhasuts glowing red !!
bloody hell i tell ya.
hope to hear some advise please.!!
cheers
glen

30 psi seems real low; stock is 43psi and some run up to 50 depending on tune.
I'm running my 30lb'SVO's at 45psi with 383 HSR

1/ timing retarted ?,
2/a/f ratio mixture is burning in the exhaust ?,
3/vaccum leak ?
4/too rich or lean ?
5/late timing ?

All possible.
I would be looking at the timing first.Back to basics , check base timing (with EST disconnected).

Quote:

Yup...

Toss in the light fuel pressure, the thing is probably running real lean.

hi guys,
how are ya!!
thanks for the replies fellas.
my problem is that im running 30 lb injectors with these 8 seperate throttle bodies and it was running very rich so thats why it was set at 30 psi on the reg.
as this old dummytest engine with stock heads and cam and is still a 350 size engine also.
r.e est timing connector,im not sure that is used any more,remember that i have a haltech stand alone ecm now,so all is different/changed now!!
but all this aside,may be i should chuck the fuel preasure guage on and try to bump up fuel preasure then,see if that helps!!
i will try bump it up to 40 psi and check timing again then!!
thanks guys
cheers
glen

Sounds like a cobbled up mess.

Quote:

The rich condition is adjusted out in the tune ; NOT the FP. Adjusting FP changes fueling across the whole range.
30's are way big for a stock cam 350; would have to take a lot of fuel out of the tune; some people run 383 with 24's

Regardless of what control system you are using , you HAVE to set the base timing.The ECM /Haltech then uses this as a reference for spark advance.If the base timing is out then all other spark timing is out.
Need to check with your tuner and see what/how he set base timing.

Quote:


yeah you reackon do ya,what would you know.
so what are you trying to say buddy?????
dont you have any thing better to say or help???
nice one!!!!
thanks for your smart ass input and btw, if you dont have any thing good to say dont bother saying any thing at all ok......!!!!!

hi vetteoz,
how are ya mate.
thanks for your contined support and help/advice r.e my problem.
its great to see you are kinda enough to help seeing none of the others here could give a fucken shit about my problem!!!!
yeah i know mate,the 30 lb are bit large to use.
i did try and boost up to 40 psi down from 30 psi but it made it bog and worse.
tomorrow i will check the base timing and see where i go from there hey.
may be i should throw the old 22 lb stock fuel injectors back in you reackon ??
but then i would have to change the setting in the lap top computer would i ??
btw, you would happen to be " rodj" from New South Wales would you and of corvette forum at all ??
you are a good bloke.
cheers
glen

I calls em like I sees em!