Idle problems/stalling since 30lb injector swap

[Grn92LX]

Heres my problem: Ever since I swapped in fms 30lb injectors my car never idled good. It either surged, stalled or idled high. I had a chip made for it ($600) and it still idles like crap, surges and stalls. Before the swap the car idled awesome, warm starts never surged, it was near perfect. Only problem with the 24's was that it ran lean. Now, I think im gonna put the 24's back in and hope it idles like it used to and then take it back to the shop for a re-tune with the 24's so its not lean anymore. Sometimes the car does idle good, but other times it surges/stalls. I cant have that, its annoying and shouldnt be that way.

ps: i was running the c&l 76mm maf w/ the 30lb tube and it idled like crap. Now I have a pro m 80mm maf for 24lb injectors but they played with the chip to get that to work. The way I see it, I have 2 options: put 24's back in and retune and this way I know the maf is for 24's or send pro m back to be re-cal for 30's and retune again. I think im gonna throw the 24's in and see..

Mike

 

[thompsonsd]

Same thing here, but I experimented and got lucky I guess. I reset EVERYTHING, Base Idle (I think the Base Idle helped more than anything), TPS, O2 sensors, timing, computer, everything. Runs pretty good now. Next I'm installing an A'pexi S-AFCII to fine tune the fuel mixture.

If neeced refer to this thread for base idle, tps and stuff, it was covered really well here: http://forums.stangnet.com/showthread.php?t=425876

 

[86Cobra]

Was your chipped burned on a dyno? It sounds like your chip guy doesn't know what he's doing. For that $600 you could have bought a Tweecer and a cheap laptop and tuned it yourself. Hindsight is a bitch huh? :damnit:

Four years ago I ran 30s on a motor very similar to yours with just a Pro-M 75mm bullet cal'd for 30s and it idled great. With my current cam and 36s I had to use my Tweecer to get the idle right (same Pro-M 75mm bullet cal'd for 30s).

 

[Grn92LX]

I don't have the knowledge on using a tweecer, im not a computer guru.

I am putting the 24's back in and i'm gonna hopefully get a reburn on the chip next week. car idled near perfect with the 24's in, hopefully it'll idle just like it used to.

 

[86Cobra]

I don't have the knowledge on using a tweecer, im not a computer guru.

It's actually really easy. You'd be surprised.

 

[jrichker]

Have you tried clocking the MAF? Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

 

[Grn92LX]

I finished car today. I took a different route than I planned. I put the 30's back in, took the chip out and put my 76mm c&l in. I had the batery disconnected over night, when I first started it up, it idled mint! Only issue it has is a warm start surge. While it was apart, I re-torqued lower intake, cleaned egv valve, cleaned maf electronics and put new upper int gaskets on. The old ones were a bit 'wet', im assuming its oil. Any idea's on that? Im gonna check tps tomorrow and may run a code test again. I lowered my FP to about 37psi vac off and put my timing back up to about 17*.

Do you guys recommend I keep the c&l or should I send my pro m 80mm back and get it set for 30's?

Mike

 

[86Cobra]

IMO, the Pro-M 80 is a much better meter than the C&L 76 or the Pro-M 75.

 

[94VIRGINIASTANG]

Grn92LX-When I got my car on the road last year I didnt have any problems for about 6 months then all of a sudden the same things started happening to me.I have the original(200,000+miles)02's.Ibought some brand new ones to put in.Im not sure if thats gonna solve my problem but its worth a try.Im not gonna blame the 76 C&L cause I didnt have one single problem for the longest time.