[fjackson]

I just put a 331 shortblock from DSS in my 1993 LX. I also install the Trickflow TFS-K514-350-370 up engine kit. I put 24lb injectors and a Pro M MAF sensor (75mm). It has a 70mm Throttle body and EGR Plate from Professional Products. My question is, do you have to swap any of the wires going to the Sensor with the Pro M. I have heard that on sensors like BBK, you have to swap 2 of the wires.

The reason I am asking, is it is loading up pretty badly....also, when I accellerate rapidly, I get poping in the intake.....

I have checked the timing and it is right on the money....it is set at 12 degrees advanced with the chip to the distributor unplugged....

Any suggestions...

Thanks

Frank

<font size=-1>[ This Message was edited by: fjackson on 3/14/06 3:47am ]</font>

 

[67stang]

The mass air meter should plug right in. Do you have enought fuel pressure? 24's are a bit small for a 331, you might just be lean.

 

[Beoweolf]

You shouldn't have to change the wiring for it to work correctly.

I do know that Pro-M is now under the umbrella of a different corp/company. I don't know if that has anything to dow with anything, but it's been my experience that when companies are bought they are seldom the same as when they were separate.

Do you have the plastic or the aluminum housing? I doubt if it has much to do with the problem, but mine is the early model, with the aluminum body...just want to make sure we are talking about the same thing.

One thing that makes a difference, is the "hot wire" clean? If it gets dirty, wet, or oily (as sometimes happens after a fresh install of a K&N filter), they will not take kindly to being disturbed until you clean them up...I use alcohol to clean the oil off.

Your engine sound pretty stout from the specs. What have you done for the fuel supply? Higher pressure, new fuel pump (they don't last forever, fox-bodies are getting up there in age, those pumps start to wear out after a while and you get lower flow)...with your engine you probably need a least a 190 or better - a 200 - 255 would not be out of the question). Check your fuel pressure, easy to do with an adapter at the schrader valve.

What rpm does the popping occur? When you say loading up, what does that mean? Black smoke out the tail pipes? Smell of raw gas? - does it clear up when you run at a steady rpm? What rpm does the problem start?

Finally...and a simple check, are the O2 senors new/clean and more important...connected?

A lot of simple basic type questions...but from what you are detailing about your set up, it seems ,more like something is not connected correctly than like something is mis wired.

<font size=-1>[ This Message was edited by: Beoweolf on 3/14/06 7:43am ]</font>

 

[fjackson]

Thanks for the quick replies....I love reading all the info in here....

now for the answers....

I bought the MAF and injectors off ebay. It is a plastic unit. I tried hooking the stock MAF back up and it really ran like crap

I also put an adjustable fuel pressure regulator (BBK) and gauge (inline). I set it as per the instructions to 41psi at idle with the vacuum off and plugged.....

I then reconnected the vacuum line and the pressure dropped to about 39 at idle.....

it just doesn't feel like it is idleing quite right....and it only pops through the intake every now and then under load....it usually happens around 1500 to 2000 rpms......

I have a solid transmission mount (stock T5, I know upgrade

but that will happen later), and it just vibrates the tar out of me and everything in the car at idle and riding down the road....I will be replacing that ASAP.....

It still has the stock (factory) fuel pump and lines. I did replace the filter (was factory also).

The reason I suspect it is loading up, is it got about 40 miles to close to 1/2 tank of gas. Even for the extra cubes and such, I think it should do a little better than that

.

I have not really gotten down on it due to it being brand new....DSS recommended 500 miles before any high rpms, but I have tested the waters without over doing it and it just doesn't feel like the power it supposed to have. From a takeoff, with a 5 speed, it really didn't want to spin the tires.....kinda dissapointing.....but I know that is because something just is not quite right.....

Thanks for all and any input on this issue.....

Frank

 

[1 Bad 88 GT]

The popping is a lean condition and unless you cure the problem or quit beating on it until you get it tuned, it will cause engine damage.

What's the expected CR with the 61cc heads?

 

[fjackson]

8.8 to 1

at least that is what DSS said....

 

[1 Bad 88 GT]

Well that changes a few things.

<font size=-1>[ This Message was edited by: 1 Bad 88 GT on 3/14/06 8:34am ]</font>

 

[1 Bad 88 GT]

Try lowering the FP to 38# with the vac unhooked and see if it helps or hurts.

 

[1 Bad 88 GT]

Do you have an open element air filter? As for the low MPG look at the O2 sensors as they will dictate to the puter what the A/F ratio is.

 

[fjackson]

On 2006-03-13 17:33, 1 Bad 88 GT wrote:
Well that changes a few things.

<font size=-1>[ This Message was edited by: 1 Bad 88 GT on 3/14/06 8:34am ]</font>

I got the lower compression, because I eventually plan to put a supercharger on it.....but this too is still a little down the line.....

Also, what does this change? And is this change good or bad...

what fuel pump and pressure would be suggested for my combo....would a 255lph be to much for a daily driver?

 

[fjackson]

On 2006-03-13 17:39, 1 Bad 88 GT wrote:
Do you have an open element air filter? As for the low MPG look at the O2 sensors as they will dictate to the puter what the A/F ratio is.

yes, K&N......

<font size=-1>[ This Message was edited by: fjackson on 3/14/06 8:45am ]</font>

 

[fjackson]

I dropped the fuel pressure back to 38 with vac off as suggested....it feels much better. However, it stumbles a little every now and then upon normal accelleration.....

Thanks for all of your help so far.....

Frank

 

[1 Bad 88 GT]

Is the stumble a new prob since you dropped the FP? Also you should be able to run a bit more initial timing due to the lower CR.

 

[fjackson]

yes it stumbles after the pressure drop....also crusing along at hwy speed, it does what I call fish biting.....feels like someone lightly taps the brake for a split second....however, it is very suttle.....

I picked up a 190lph pump today and will install soon.....I will raise the timing up some and post results.....

Thanks for all your help on this......sure don't want to mess up this engine.....I am refraining from anything above normal driving....

I also got a new PMAS (Professional Mass Air System) mass air meter....75mm calibrated for 24lb injectors....I am not 100% sure the 75 I got off ebay is up to par.....

Thanks again

 

[raheed2]

I would also check the TPS sensor as the fish biting you describe can be the sign of a worn or flat spot in this sensor.

 

[fjackson]

OK guys, here's an update.....

put 190lph fuel pump on it....and brand new 75mm mass air unit, and upped the timing to 14 degrees....it feels like a totally different car....it does very very well now.....still notice some slight fish bitting while cruising on the highway, but not much....the popping and stumbling have gone for now.....

Thanks to all who helped with this.....

Next will be the tranny....I am sure the factory T5 is not going to hold for long.....

I have a 10 spline Centreforce clutch and 28 spline drive shaft....what would you guys recommend as a replacement that will not break the bank....

Thanks again.....it is becoming a joy to drive again.....

Thanks

<font size=-1>[ This Message was edited by: fjackson on 3/17/06 7:01am ]</font>