90 Lx 5.0 Rebuild

[dwb]

Hey all.. new here. Go easy on me.

Spent some time reading and while every issue can be its own unique cup of tea, figured I would ask the pros for some advice.

Some info I post here might be irrelevant but I don't know a lot about cars so posting as much as I can if it helps.


I have a 90 5.0 that I just finished doing a cam, head, intake swap on. The main rebuild like cam install, setting rockers and lower intake I had the help of a family heavy duty mechanic so my noobness had some help. Also had his help setting timing. Doesn't mean it's perfect but at least I wasn't solo being new to this.


So
- new comp cam (don't know specs sigh) was from a buddy's new build he ran for a week then wanted more power so did a full engine swap.
- new AFR 58cc heads (his heads)
- new push rods (his rods)
- new lifters (his lifters)

- new comp rockers - 1.6 ratio
- edelbrock Performer RPM 2 intake
- BBK 70mm throttle body
- BBK cold air intake
- new MSD distributor cap only and new plug wires
- new spark plugs

- deleted ERG and probably all emission stuff

- stock fuel injectors
- stock rails
- stock mass air sensor
- stock water, alt, power steering pump
- stock headers
- stock exhaust

- deleted smog pump


Fired the beast up and it sounds mean, it idles perfectly, to me anyways.. revs up good.

Hear a bit of a whine or squeal which I think might be a vaccume leak somewhere.

Problem:

no power.. driving it down the road it just doesn't want to go. Best way to describe it would be driving in to high of a gear for the RPMs you are at then pushing the gas. But it doesn't sound like it drowns out when you push the gas just drives. Think a mono toned person talking. That's this beast even in second gear.

Not sure where to start... new mass air sensor? Get a code reader and see what's going on with the newly deleted stuff? New injectors needed with all this new air flow ?

Just take it to the local dyno shop for a tune ?


Any advice would be awesome.

 

[dwb]

Did a KOEO test and got codes 98 & 51

 

[FoxMustangLvr]

- stock fuel injectors
- stock mass air sensor
- stock headers
- stock exhaust

.

These are big problems. You added a lot of air flow with the heads, cam, and intake and now it's breathing through a straw with the stock throttle body, stock MAF, etc. You need at least a 75mm MAF and a 70mm throttle body fed by a cold air intake that goes in to the passenger side fender well. You also need 24lb injectors and a fuel pump upgraded to a Wahlbro GSS340 (255lph fuel pump). Your stock fuel rails are OK with your setup. Make sure your MAF is compatible with the 24# injectors. You also need to get the vacuum leak fixed too. On the exhaust side some shorty headers and upgraded mid pipe and mufflers will help the engine breath as well.

Edit: disregard the throttle body and cold air intake comment, I re-read and found you already have them.

 

[FoxMustangLvr]

Did a KOEO test and got codes 98 & 51

51 - Engine Coolant Temperature (ECT) sensor signal is/was too high – ECT

98 (R) Did not pass KOEO yet (Get 11 in KOEO first)

@jrichker for a more in depth perspective

 

[dwb]

Appreciate the reply.

I will go ahead with the 24lb MAF and injectors. I was already thinking about doing the 24# injectors so may as well just do it now if I'm putting money out on a new MAF.
One day I will want to super it but who know when and then I will need bigger injectors, MAF blah blah but. That's the name of the game right.

 

[FoxMustangLvr]

Appreciate the reply.

I will go ahead with the 24lb MAF and injectors. I was already thinking about doing the 24# injectors so may as well just do it now if I'm putting money out on a new MAF.
One day I will want to super it but who know when and then I will need bigger injectors, MAF blah blah but. That's the name of the game right.

That's just the way it goes, sometimes our time and/or budgets don't allow us to go "all in" at once. This creates a do it twice and waste money situation but that's just the way it is for us. You can always make some money back selling the 24# injectors and MAF down the road when you upgrade again. Check out the classifieds section here and on Corral for some good deals. Corral is where I found my injectors and other decent deals. Make sure you protect yourself by paying through PayPal and checking peoples feedback.

 

[jrichker]

b]Code 51[/b] Engine Coolant Temperature (ECT) sensor signal is/was too high -

[color= blue]Revised 6-Apr-2017 to add diagrams and resistance check for ECT wiring.[/color]

Possible bad ECT sensor or wiring. Possible missing signal ground – black/wire broken or bad connection. With the power off, measure the resistance between the black/white wire and battery ground. You should see less than 1 ohm. Check the same black /white wire on the TPS and MAP sensor. More than 1 ohm there and the wire is probably broken in the harness between the engine and the computer. The 10 pin connectors pass the black/white wire back to the computer, and can cause problems.

The computer Engine Coolant Temperature sensor has absolutely nothing to do with the temperature gauge. They are different animals. The ECT sensor is normally located it the passenger side front of the engine in the water feed tubes for the heater. It has two wires that connect by a weathertight plastic connector.

The water temperature sender for the temp gauge is located in the driver's side lower intake manifold. It has a single wire that connects by a push on connector on the temp sender.

If you have replaced the ECT sensor and are still having ECT like problem symptoms, check the ECT wiring .

See the graphic for the 10 pin connector circuit layout.

Check the resistance of the green wire on the ECT connector to the green wire on pin 7 of the computer connector. You should see less that 1 Ω (ohm)

Use Pin 46 on the computer for ground for both ECT & ACT tests to get most accurate readings.

Pin 7 on the computer - ECT signal in. At 176 degrees F it should be .80 volts

Pin 25 on the computer - ACT signal in. At 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.

50 degrees F = 3.52 v
68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61
212 degrees F = .47 v
230 degrees F = .36 v
248 degrees F = .28 v

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.

50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms
212 degrees F = 2.07 K ohms
230 degrees F = 1.55 K ohms
248 degrees F = 1.18 k ohms

Diagram courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Code 98 - basic computer internal tests not passed before it started processing the request to dump codes. Do a Key On Engine Off test before starting the engine. Wait until you see the 11 flash before pressing any buttons if you have a hand operated scanner. The computer is operating in Limp mode, so fix any codes it dumps prior to doing anything else.

 

[dwb]

Holy. Tons of info.
Much appreciated. I will have a more in depth read when little one is in bed lol.

Hey is it normal for the header where four of the pipes connect to be glowing orange only idling for like 5 minutes? Car temp wasn't bad

 

[General karthief]

I would think that is a sign of an extremely lean condition, not sure.

 

[dwb]

Yeah just did some searching on here and reading the debate on it being too lean or too rich and timing to retarded. Will keep on reading. Just going to leave the beast off for now. Don't need no hole in a piston.

 

[Mustang5L5]

Idling should not get the exhaust glowing red. Sounds you are very lean on that side. Something's going on there.

 

[dwb]

Checked timing. Was probably 4-6 degrees before TDC. Moved it to 12 and night and day difference in performance.
Shot the headers with temp gun and was about 650 in that short idle messing with timing then going around the block here in Canada where it's 45 degrees F out so. Hopefully the new MAF and injectors will settle the air/ fuel down and see some improvements there.

But so far progress.
Thanks all

 

[Steel1]

If the sound you here is more like a whistle it could be caused by the BBK throttle body, pretty common with them.
I have a 75mm BBK that has a slight whistle at idle but not enough to bother me.
Some people drill a small hole in the butterfly to prevent this.
Just figured I'd mention it before you start chasing a possible vac leak.

 

[dwb]

Is it normal for the initial timing to be different with the "grey" plug removed versus when you put it back in?

 

[General karthief]

Yes, with the spout (gray plug) out your timing is locked and the computer does not control (adjust) it, plug it in and the computer takes control and will use sensor imput to adjust timing.
Thats a short answer, anything more precise is beyond my pay grade.

 

[dwb]

Another question for the pros

I'm getting a 30# MAF and 30# injectors.. should I be getting an adjustable fuel reg to increase the psi or will the stock "39" be fine?

And I'll have to google where the heck the "vaccume" line is that should be unplugged and plugged?

 

[General karthief]

I don't think you need 30lb injectors but I'm no expert.
If it's running good now check to see if you have any codes and enjoy the ride.
Oh, and that vacuum line I think you are referring to, the fuel punp regulator? Look behind the throadel body at the back of the fuel rail is a round thingy with a vacuum line in the center.

 

[JD1964]

Set timing at 12 with spout removed. Plug spout back in when done.

 

[dwb]

Thanks for replies.

I was going to go for 24# MAF & Injectors but plan to drop a super in it next summer so may as well just put 30# in so I will be in the 430-450 capable range without changing the 24's out

 

[JD1964]

I have an s trim on my 92 pushing 8-10 psi. I’m probably just shy of 400 rwhp. I have 30lb inj and they’re maxed out but just barely. I need to turn up the fuel pressure to about 47-48 to get my wot a/f mixture to the sweet spot of 11.8. It’s working perfectly since I can change my wot mixture simply by raising or lowering fuel pressure a few lbs either way.

Anyway, if you’re future goals are 450ish hp, I’d say maybe 30lb would be too small.

For sake of comparison let’s say I had 42lb. They would be less than maxed and my wot a/f would be fixed at whatever the tune was.

Most people say the injectors should not go beyond 80% duty cycle. But I’m breaking that rule and surviving just fine, with a benefit of the ability to fine tune wot a/f without needing to re flash the chip.

Sorry for rambling but picking an injector size that will work good in your current na application and also have enough room in a boosted application my be tricky