mefordguy

I have a 93 LX with a low mileage 302 FRPP crate motor. I bought the car with no top end. I put on a cobra intake, used 24# inj., 70mm TB, all the basics. After getting it running I had a miss and some backfiring though the manifold. So far i have replaced the injectors, plugs, cap, rotor, plug wires, distributor, and TFI module. I am fouling plugs 3,4,5 and 7 and the car wont make any power. Its not throwing any codes. I have worked on these cars for years and have never had a problem like this. Its not a stuck lifter or a bad valve spring, and all 8 cyl have good comp. A local mustang shop even looked at it and they are puzzled. I'm thinking maybe the computer has gone bad. I am trying to borrow one so I can test it, but I'm having no luck there. I dont want to purchase one unless i know thats the problem. The plugs that are fouling are getting good spark, but when I pull a plug wire, there is no change in idle. The timing on the car is perfect. Anybody ever had this problem or have any suggestions?

mjr46

did you stab the distributor properly??? and if so are you using the proper firing order that'd correspond to what ever cam is in there which if a h.o roller cam it should be 13726548

mefordguy

yeah, all that is correct. I'm thinking its something with the fuel. The 4 plugs are black as night and wet with gas. For some reason I am getting too much fuel to those 4 cylinders only. And with brand new injectors thats puzzling to me. Is there a sensor that could cause such a problem? Every sensor on the motor is new except the baro sensor and the TPS. Thats why I'm wondering if the computer may be faulty. I even double checked to make sure my C&L mass air was properly calibrated. I'm running of ideas.

mefordguy

Well, I decided to do something since I have tried everything else. I switched the plug wires to the non-HO firing order. I'll be damned if it didnt run perfect. Apparently, the motor doesnt have a B-303 like I thought it did. Now I just need to find out what cam it has. Car is laying down some good power. Has ported FRPP alum. heads, cobra intake,5-speed, and 3.55 gears and a every bolt-on known to man. Now its running like it should be.

AdderMk2

you should stop running it until you either... A) swap your injector firing pattern so you dont burn up those 4 cylinders or B)put in an HO cam

mefordguy

Yeah, that is the plan. I have an f-303 on the shelf, but I think I'm going to run either a trickflow stage 2 or an Anderson cam.

mjr46

So no all that wasn't correct, like I said firing order

projectresto83

Its amazing how easy it is to screw up the timing and then skip over it not thinking it is the problem.

mjr46

you need to do as addermk2 says and as soon as possible perform the swap since your efi is SEFI = inj fired sequentially in accordance with the h.o firing order, even though you have the ignition firing order in agreement with the cam firing order, although car seems to run fine, you will be running lean on some cyl's so do cam swap asap

mefordguy

Already in the process. I am just using the f-cam that was on the shelf. Should be back on the road sunday.