drivability with H/C/I 302, full bolt ons.

[dderek]

well, everybody with H/C/I... did you have your car dyno tuned? or a custom chip burned?

because. mine, runs like garbage. ive set the timing to 10 degrees. fuel pressure to about 40. and it misses at idle. and causes bad shakes.
it seems fine at high rpms. but daily drivability is garbage. bucks and misses throughout low rpms mostly when its cold. its not as bad when its warmed up.


Now, everybody with H/C/I... how smooth is your car? how did you tune it? a dyno shop burn you a chip? you buy a tweecer/pms/etc?..

just looking to see how everybodys car runs


ALSO:
Which is better, tweecer, pms? or the other brand one.. AEM i think?
tired of my baby running like trash

 

[grey5.0beast]

Timing you should set at 12-14* . You shouldn't need a tweecer/pms with just HCI. What injectors are you running? When was the last tuneup and what sparkplugs did you use??

 

[mustangsally93]

Mega squrit it man. with a paxton novi2000 heads x303 bbk upper and lower intake it make it run like new. Its a all around computer for the car. Its great for $1000 in stalled. works great

 

[2002BLGT]

what MAF , what injectors , what heads , what cam , what intake , what throttle body .....

if all else fails , put the stock MAF , injectors etc back in , but leave the intake , heads and cam that you installed , check the injector wires on cylinders 1 and 2 on the passenger side to make sure those 2 arent crossed, set timing at 12-14 , set fuel pressure at 38 with vacuum off and plugged, set your idle up to about 900 rpms when engine is warmed up ..then double check the TPS voltage to make sure its between .92 and .99 , double check the number on your spark plugs and gap and all the little stuff like that as well , and it should run fine ......if it runs fine then , put whatever injectors and MAF you might have for it on and adjust the fuel pressure from there but unless your running some AFR 185s or better flowing heads then you probably dont have to have bigger injectors and you can run a MAF off of a 94-95 GT ....

 

[sick95gt]

Mine ran ok without a tune. I haven't gotten a tune/tweecer yet. I only drove it 2 days since the install though. My clutch went out and I don't have the money to replace it yet.

 

[srothfuss]

Regardless of part's installed, the motor shouldn't buck / miss or resist forward motion. Something doesn't seam right.

 

[Pro Mod]

probably something in your MAF/injector calibration...

Here's the dyno & A/F graph from my 5.0 with the following:
AFR 165's, Cobra intake, Trick Flow Stage 1 cam, FRPP 1.6 rockers, MAC shorty headers, MAC X-pipe, MAC catback, MAC pulleys, Moroso CAI, FRPP 65mm tb, Pro-M 75mm Bullet MAF, 24# injectors, 190 lph fuel pump.

My EEC was stock, timing was around 13*, and fuel pressure was around 36. It drove like a CHAMP, even averaged 19 mpg and got me 26 mpg on the trip down to Mustang Week this summer.

View attachment 492163

I credit most of the flat A/F graph & the driveablilty to the Pro-M MAF.

 

[dderek]

well, i have the following

Ford 24lb injectors.
Granatelli mass air meter, for 24lb w/ cold air tuning (probably junk)
Trickflow twisted wedge heads, cnc ported/polished. dont know the specs. but the ports are alot bigger. probably too big for my 302. but too late now.
ford 'b' cam
full msd ignition
autolite 24 sparkplugs. didnt change the gap or anything. just screwed them in and went with it. never had problems doing that with my '86 or '88.
Timing at 10*

like i said, it will run like **** until its warm. 170~ish. (180 thermostat)
then it will run awesome sometimes, and buck/miss like hell others. ill just hold the pedal to the floor.. and the car will jump around having a hard time even accelerating... rpms barely climbing. then it will hit like 3K and the car will just kick in and take the **** off. so, it runs great HALF the time. usually the higher the rpms w/ WOT the better.

at idle the car misses im guessing. and the vibrations cause the ****ty bbk intake to tap on the strut tower. extremely annoying.. but the shaking disapears at higher rpms. and ive replaced every single rotating peice except engine internals. so im guessing its in the tune.

is it a bad mass air meter? needs a tune?

 

[Quikstang]

Yea, sounds like you should go through and check some things. I have a similar combo as you, 306, Edelbrock 6037's, 1.72's, b cam, 10:1.1 comp ratio, I ran 14 degrees of timing an 35 lb of fuel pressure. My car ran strong all the time, trapped high 108 - 109 on street tires all day long in the summer. It was my daily driver, only time i have ever had problems with some of the things you described was when I had FRPP plug wires, car ran like complete $hit, wires arced right out of the box... sounds like a tuning issue, weather its fuel or spark,...

 

[mustangdaren]

Is this your first H/C/I car? Just wondering if you're confusing cam lope for the engine missing. With the B-cam and factory gearing 2.73 or 3.08 the car will feel sluggish under 3k and even with proper gearing it's not going to change the power band but will help you get in the power band sooner. Also the car will be more cold natured and run a little rough until it gets to operating temp, some are worse than others. My car actually idled better and had less cold natured behavior when I was running a Cartech upper intake but the low end torque sucked. Without a piggy back computer or chip there is not much way to fine tune for driveability issues. You could try clocking your MAF if you are running a cold air kit, this has helped some with driveability issues. I have seen restrictive exhaust cause idle surge when I first got a H/C/I combo. I had a bad surge that I tried everything to figure out, even using a bypass plate on the IAC. I switched from 2.25 flowmaster cat back to 2.5 MAC cat back and the car never had a surging problem again. About the best advise I could give you is take it to a tuner with a mustangdyno and put it on the dyno to check air fuel under load. He may be able to find and cure your problem doing basic tuning (TPS, FP, MAF clocking, timing, ect) without having to do a custom chip.

 

[2002BLGT]

well, i have the following

Ford 24lb injectors.
Granatelli mass air meter, for 24lb w/ cold air tuning (probably junk)
Trickflow twisted wedge heads, cnc ported/polished. dont know the specs. but the ports are alot bigger. probably too big for my 302. but too late now.
ford 'b' cam
full msd ignition
autolite 24 sparkplugs. didnt change the gap or anything. just screwed them in and went with it. never had problems doing that with my '86 or '88.
Timing at 10*

like i said, it will run like **** until its warm. 170~ish. (180 thermostat)
then it will run awesome sometimes, and buck/miss like hell others. ill just hold the pedal to the floor.. and the car will jump around having a hard time even accelerating... rpms barely climbing. then it will hit like 3K and the car will just kick in and take the **** off. so, it runs great HALF the time. usually the higher the rpms w/ WOT the better.

at idle the car misses im guessing. and the vibrations cause the ****ty bbk intake to tap on the strut tower. extremely annoying.. but the shaking disapears at higher rpms. and ive replaced every single rotating peice except engine internals. so im guessing its in the tune.

is it a bad mass air meter? needs a tune?

double check your part number on the plug you have in there , not sure what trickflow recommends on their heads .....that MAF will do just fine , I am running one without any issues at all , might want to set your idle up to about 900-950 with that cam though ....

 

[dderek]

yes, this is my first h/c/i car. and.. i understand a lopey idle and a miss.. ill go make a video today, of how the car runs cold.
then you guys will REALLY understand how extremely terrible it runs.
ill be posting back today with video results

 

[2002BLGT]

yes, this is my first h/c/i car. and.. i understand a lopey idle and a miss.. ill go make a video today, of how the car runs cold.
then you guys will REALLY understand how extremely terrible it runs.
ill be posting back today with video results

you have to remember , on cold start up the engine is gonna run messed up because it was tuned for a stock engine to run within a set number of parameters , now that you have changed things it throws that off , it doesnt start reading from the sensors to make it act right until the engine is warmed up .....tune it the best you can with it warm , might wanna set the fuel pressure to 37 if its really rich when cold ......with 24s its not going to hurt ya one bit .....when you have it running good when warm then the cold running will be as best as its gonna get until you pay a arm and a leg to get a tune done on it

 

[Dbeck002]

Ok first of all your setup sounds fine. You MAY have a vacuum leak, check everywhere 10 times.

I personally think it is your TPS sensor, my car had serious idle issues until that was adjusted and i have the same cam you do.

As for the cam, it bucks under 1500 rpm because thats the nature of the cam. My car was dyno tuned and still does it because thats just how performance cams feel. They choke the engine down low but kick in up top.

Your scenario might still be something a little more severe than just cam bucking. Check the little things first.

 

[mustangdaren]

Ok first of all your setup sounds fine. You MAY have a vacuum leak, check everywhere 10 times.

I personally think it is your TPS sensor, my car had serious idle issues until that was adjusted and i have the same cam you do.

As for the cam, it bucks under 1500 rpm because thats the nature of the cam. My car was dyno tuned and still does it because thats just how performance cams feel. They choke the engine down low but kick in up top.

Your scenario might still be something a little more severe than just cam bucking. Check the little things first.

Yeah, that was what I was thinking too. Mine idles and runs like crap cold and under 2k bucks and feels like it is missing at any temp. I chased my tail for about a year replacing parts before I realized that is just how it is going to be without a custom chip.

 

[88Stangboy]

I have an F cam in my Mustang, and my car has never bucked in the low rpms. In my 67 Camaro i have a cam with .560 lift and it doesn't buck in low rpms. The Camaro is carb'd and the Mustang has EFI. Check your timing again and make sure you dizzy is locked down good. A buddy of mine replaced half his ignition before checking that and the dizzy had come loose and his timing had gotten off.

And check for a vacuum leak like they said. Vacuum leaks can cause your car to do some crazy ****.

 

[mustangdaren]

Mine will chug with the lope of the cam under 2k in the higher gears.

 

[Dbeck002]

I have an F cam in my Mustang, and my car has never bucked in the low rpms. In my 67 Camaro i have a cam with .560 lift and it doesn't buck in low rpms. The Camaro is carb'd and the Mustang has EFI. Check your timing again and make sure you dizzy is locked down good. A buddy of mine replaced half his ignition before checking that and the dizzy had come loose and his timing had gotten off.

And check for a vacuum leak like they said. Vacuum leaks can cause your car to do some crazy ****.

Lift and duration alone arent what cause the bucking, its more the lobe seperation angle. Basically the intake and valve are open at the same time causing the intake to blow out the exhaust at LOW RPM, at high RPM the exhaust aids intake by scavenging. So with a 112 LSA i get the bucking at low RPM, i think F cams have 114 which is more drivable.

 

[Bad92GT]

try it at 17 degrees.. its better to run it there with that kind of setup.. check your fuel pressure also..

 

[88Stangboy]

yea, i understand what overlap is. Mybe you should try some better rear gears. You may not have the right set with your cam. Just like with an auto, you put in a cam, better get a higher stall coverter to. Cam's in man. tranny's need higher gears so that when you shift your rpm's don't drop out of your cams power band. sorry if this post was a little "back to the basics"