Travis Carson

(95 XL bronco, 302ci w/ 5speed)
I already know before you guys flame me on this becuase I know there are literally millions of threads on this topic but all I ask is to hear me out becuase it's starting to turn into a bizarre situation here and any help is greatly appreciated. So let's jump right into it. My bronco misfires when I press the throttle anymore than 1/4 and if i go to the floor it turns into a full on dead cylinder. It idles beautifully though. So the first thing i did was gave it an simple engine tune up, cap/rotor, wires and plugs (all 8 were a dark tanish coffe brown and I used motorcraft for everything) and that still did nothing. Soo I'll just give a giant list of everything that I have done so far that has snowballed to me coming to a lost
coil pack
Map sensor
02 sensor
throttle positioning sensor
iac sensor
douched out the plenum
feul pump and filter. (Also checked relays)
brand new distrubor
I then deleted egr valve with plugs and resistor plug in for ecm
I then got a scan code reader which told me I have rich and lean running conditions. (Seems like fake news considering the plugs were perfect?) And that the map sensor does not have sufficient vacuum pull (hooked up an vacuum reader and I'm pulling 18 inch pounds of mercury? So vacuum is good) I'm at a lost and about to slap a 347 stroker in becuase I know that will fix it! Lol. Any help is greatly appreciated. Thanks, travis

Steve83

I wouldn't expect a '95 5.0L to have a MAP sensor. It certainly doesn't have a coil pack - just 1 simple coil. Where exactly was the oxygen sensor you changed? Exactly how did you check which relays, and what did you find? I don't think MotorCraft still offers a new distributor for these old engines - where did you find it, and what was the PN? Do you still have the original parts? You should probably put them back on since there's apparently nothing wrong with them, and they're probably more-correct for the engine. You should CERTAINLY put the EGR system back on, and maintain it properly.

To help you, we need to know a LOT more about the truck & its history. When & how did this symptom appear (time, miles, suddenly/progressively...)? Have you maintained it according to the published schedule? All its details need to be in your signature so we can find them, as this caption explains:


(phone app link)

Swapping the engine is no guarantee of fewer problems - it's usually a recipe for MANY MORE.

mmk

oops

Travis Carson

1.) Ford got rid of the map sensor on the 96 models and went to maf.
2.) I was talking about the ignition coil
3.) There is only one 02 senor and it's right off the manifold
4.) I just slapped new relays in the fuze junction box
5.) I got a cheap dizzy off of ebay of ebay because I was not even sure if that was the prob. And yes I still have the original
6.) And far as history goes for the bronco. The only thing I know it has 140xxx. I just recently got it off a dude on craigslist and I'm trying to fix her up. So you pretty much know about as much as I do lol..

Steve83

6: If you read that caption & do what it says, we'll all know a lot more about it.

You're wrong about 1 & 3. MAF was optional in '94-95, and those trucks had 2 HEGOs. '96 trucks had 3 HEGOs. And a V engine has 2 manifolds - which one (driver's or passenger's) did you replace the HEGO near?


(phone app link)


(phone app link)


(phone app link)

4: There are several relays in the PDB, depending on what options the truck has. Which ones did you replace, with what (brand, PN, source)?


(phone app link)

5: So when you said "I used motorcraft for everything", you forgot about the distributor? If you suspect any ignition system problem, follow the diagnostic procedure in this caption:


(phone app link)

Travis Carson

I'm sorry I should have clarified a little better. Standard models did not come with MAF. And there is only one 02 sensor. Theres a bung that connects to both manifolds which that is were the o2 sensor reads off of And I only used motor craft for the plugs wires and cap and rotor and relays are just an autozone special I did a while back

cant see the pictures you have sent through my phone so when I get home I'll hop on a PC and blow it up. Thanks for the help. I'll get back to you later. I got alot of homework to do lol

Steve83

Ford only makes standard models. But it makes MANY of them, including several '94 & '95 MAF F150s, as those diagrams indicate. They have 2 HEGOs.

If you click the "phone app link" text below those thumbnails, your phone should open the pics correctly.

Chris_1

iTrader: (1)

1 oxygen sensor up till 95 - at the junction of the pipes just before the first cat. On most 5.0 models , both SD and MAF. 96 went to 3 O2 sensors.
Based on what you're having trouble with and what you've changed, I'd be looking first to see if you routed the spark plug wires according to the way Ford says to do it or if you lined them up all neatly in order.
There's a problem with cross-firing under load with the 302 if you don't route the wires properly. Might possibly be your problem. There should be a diagram on your rad saddle if it's original.
Worth having a look in case it's that simple.

Steve83

All '95 CA-emissions MAF (& probably some other configurations) have 2 HEGOs.