90 Lx 5.0 Rebuild

[dwb]

I was looking over the American muscle site on injectors and they had 24# injectors rated to 358HP. Might not be rwhp but figured I would hope I would be closer to 400 after dropping a super in it so 30# were listed as 448. Can't say right now I have an end game. Just wanted to build a top end that could support a supercharger without having to redo the deeper guts.

 

[General karthief]

Swap'n a set of injectors is not much harder than an oil change

 

[dwb]

Installed the new injectors & mass air meter and now I'm having issues going over 3500 rpm. Engine Cuts power.

Did some reading here.. think if she worked fine before the latest change I could need a new TFI module?

 

[dwb]

Oh I also got a bama 4-Bank eliminator chip I haven't installed. I know some say they crap but worth trying it to see if it corrects this issue?

 

[General karthief]

Thats a good way to create more problems, fix it first then try the chip.
Have you checked for codes?

 

[dwb]

Just ran the KOEO

51, 23, 31, 67

23 & 67 are new

I deleted the EGR so 31 is explainable.

 

[dwb]

Don't think I added in the first post about the power failure after 3500. It idles like crap. Up and down from like 700 rpm to 1100rpm some times sounding like it's about to stall out so thought my throttle body wasn't open enough for idle so opened it a bit with the set screw but not sure I needed to as it was fine before

 

[dwb]

I'll go push clutch in when dumping codes. Might be why I got a 67. But nothing else in those codes to explain the 3500 power kill

 

[General karthief]

So you had problems reving past 3500 right from the begining?

 

[dwb]

No not at all. Everything was fine my only issues was timing causing lean issue and heating up the headers to glow.

So adjusted timing. And temp went down. Ran way better.

Put in new MAS and Fuel injectors. Idles rough, bounces on and off from 700 to 1000/1100 and almost sounds like it wants to stall out.

When I drive it in first gear over 3000-3500 power cuts out. When I go into second gear and get towards the 3000,3500 mark it gives out.

 

[dwb]

In neutral reving it up is fine

 

[General karthief]

Go back to the old injectors and maf.
Question: did you reset the computer after changing the injectors and maf? And check your fuel pressure too,

 

[dwb]

No didn't do anything with computer or anything.

Put in injectors and MAF and fired it up.

I will check fuel pressure

 

[JD1964]

Are you running a filter on the end of the MAF? Silly question maybe but I tried running mine without a filter on a test drive and it sputtered out early like you describe. If you are running a filter, try rotating the MAF to a different clock position. They're finicky like that sometimes.

 

[dwb]

No filter. I noticed the stock MAF housing had a screen type filter on it but this BBK had nothing

 

[General karthief]

Your running it with no fiter at all?

 

[dwb]

Like.. just the MAF housing? No..

I have BBK cold air intake. So filter on the end of the intake... I didn't think this pos MAF needed its own filter if it didn't come with one

 

[JD1964]

Mine wouldn’t run right without the filter installed. It has to do with the way the filter breaks up and balances the airflow right before it goes though the maf.

 

[JD1964]

If you have a filter mounted on end of the air tube you’re good there. That’s what I meant. Try clocking the maf 90 degrees and see if it helps.

Is the maf and injectors rated the same? What lb?

 

[dwb]

Yeah same rating. 30lbs.

The old MAF tube. Like stock has a screen type filter on it. Just the BBK didn't. I thought why would stock and not this but didn't think anything and put her in. I'll see what I can find to use for a filter.