Why cant I keep my 89 LX started

[stevesLX]

I have a 89 lx 302 bored 30 over with a lengthy list of mods. I put o2 sensors on it and changed the plugs and the wires. But it still wont stay started after it sits for a while until it warms up. 24# injectors, BBK throttle body, 65CFM MAF Edelebrock plenum and intake. I have tried to retard the distributor some and she wants to fall on her face then. I am ready to throw in the wrench now. I am so sick of spending money on this thing. I dont think it matters but the harness that plugs into my 02 sensors came off of a 1987 GT. The plug on the end of it the female side only had 5 connections on it. the male side of the plug that goes to the computer however has 8 prongs on it. I know it has to be working though because I was running without any o2 sensors in the beginning and my gas consumption was off the charts. It has since improved. But maybe I need the other harness that has 8 connections like the male end of my harness does that goes to my computer. I dont know I give up.

 

[RsStanG1987]

Timing issue or look for Vacum leaks.. Post in tech for more help..

 

[2000xp8]

The o2 harness may be part of the problem. I saw it first hand at my friends shop. You need the one that matches the year of the rest of the harness.

 

[Strype]

I had that problem and MyBad70 found the solution after about a year of it cutting out on me...

Lock cylinder (ignition) was falling apart.

+1 for vacuum and timing. Make sure it isn't jumping time.

Oh, and a bad distributor will always cause that problem. There's a little green piece inside them that goes bad.

 

[stevesLX]

I had that problem and MyBad70 found the solution after about a year of it cutting out on me...

Lock cylinder (ignition) was falling apart.

+1 for vacuum and timing. Make sure it isn't jumping time.

Oh, and a bad distributor will always cause that problem. There's a little green piece inside them that goes bad.

Are we talking the distributor or the cap? And what exactly is the lock cylinder ignition. Bear with me here I am a newbie. +1 for vacum & timing. Could you please explain?

 

[Strype]

Are we talking the distributor or the cap? And what exactly is the lock cylinder ignition. Bear with me here I am a newbie. +1 for vacum & timing. Could you please explain?

First things first

read jrichker's write up on no starting. I'll look for it.


Me personally? I'd do this...
1) Check your timing. There is a wire connected to the distributor. It holds a grey plug. Pull that out and put it in your pocket. Then time the car from 10-14. Make sure that you can see the timing mark at all times and that it doesn't drop to a lower number or jump to a higher number.

If it is jumping around (provided you took out the grey plug) then you have an ignition system issue. Most likely this is your problem and Mustangs are known for their crappy distributors so the distributor is a start. I'd change it whether the timing jumps or not, but you may not want to. If it still cuts out on you take it back and get a refund.
When done with timing replace plug

2) Check the starter solonoid. It's the little black round box thing the size of a baby's fist on the driver's inner fender well connected to the battery.

3) Check the coil located right beside it.

4) Vacuum. Do you hear any loud pitched whistling sounds? If so spray carb cleaner around the intake, throttle body and spacer until it stops for a second. That means you just sprayed the hole. Replace gasket or hose as necessary.

 

[Strype]

PS: If you haven't already, pm Daggar or Mustang5L5 and have them post this in the tech section so some of the more experienced members can help you out. You're not gonna get a lot of help in this section

 

[Strype]

Ahhh... nevermind I see you already did.

 

[HISSIN50]

Are the MAF and injectors in synch?

Any codes?

It might be as simple as needing to clean your IAC or that your ECT went south. But additional info would be nice (there's not much to go on).

I'll second Strype's advice to read and follow JR's checklist.

Good luck.