302 issues

86bluecobra · Jan 19, 2007

My 302 in my F-150 has some issues. seems to have hesitation almost miss when cruising down highway in O/D or just drive. no real codes. its a Maps 302. how do you test wether coil is still good. spark seems weak. sometimes it stalls and will not fire by cranking it over unless you hold gas pedal on floor. perhaps flooding but i don't know how to check if injectors are leaking. i always get a rich code. i did install a new o2 sensor. now a little info on the truck. I have a computer friendly comp cam. i have shorty headers and off road h-pipe. it does smell rich.

HISSIN50 · Jan 19, 2007

Before we go off on tangents, could it be trans shudder (since you noted OD, if it is an electronic trans, it made me wonder).

No codes?

To test injectors you kind of have to pull them and test them while they are de-energized.

If you can see the MAP calibration, that would be big, esp with the code.

Let us know what iteration of EEC this is. If late enough EEV IV for instance, you can view PIDs.

Good luck.

greg251 · Jan 19, 2007

Check your fuel pressure while running and while driving. If it is a dual tank F-150 try switching tanks and see if that helps. If it does then suspect a fuel pump or FDM. Also check for vacuum to the fuel pressure regulator. Bad EGR or connector will do the symptoms you describe as well.

86bluecobra · Jan 20, 2007

HISSIN50 said:
Before we go off on tangents, could it be trans shudder (since you noted OD, if it is an electronic trans, it made me wonder).

No codes?

To test injectors you kind of have to pull them and test them while they are de-energized.

If you can see the MAP calibration, that would be big, esp with the code.

Let us know what iteration of EEC this is. If late enough EEV IV for instance, you can view PIDs.

Good luck.

This is a 1992 F-150. How esactly do i see the MAP calibration? I don't believe it is a tranny shudder it is doing it in Drive aswell when the O/D override is pushed. I am getting a couple of EGR codes.

86bluecobra · Jan 20, 2007

greg251 said:
Check your fuel pressure while running and while driving. If it is a dual tank F-150 try switching tanks and see if that helps. If it does then suspect a fuel pump or FDM. Also check for vacuum to the fuel pressure regulator. Bad EGR or connector will do the symptoms you describe as well.

Yes i am getting EGR codes but if i disconnect the vacuum line to the top of the egr i still have this issue with a miss. The thing is it isn't always there either. sometimes the truck runs great no issue other times it is horrible.

86bluecobra · Jan 20, 2007

HISSIN50 said:
To test injectors you kind of have to pull them and test them while they are de-energized.

Good luck.

So how exactly. I have no problem pulling them.

greg251 · Jan 20, 2007

If you have access to a scanner try a wiggle test in the connectors. I had a problem like that on my 1990 F-150 and the connector was bad going to the EGR. If I remember correctly the sensor on top of the egr is called the EVP. They are known to go bad as well. Have you checked the vaccum on the engine as well?

HISSIN50 · Jan 20, 2007

86bluecobra said:
So how exactly. I have no problem pulling them.

You can pull them and hook up compressed air to the injector and see if it holds. This can be difficult to monitor. A real nice tip to augment this test is from JRichker. You put the tip of the injector in water with a drop of soap in it. If the water gets bubbly, you have a leaking injector.

I really kinda doubt it's a leaky injector though. The source of the MAP code can probably cause some real hard starting and a miss at cruise, for instance. That's where I would begin right now. JMHO.

Good luck bud.

vristang · Jan 20, 2007

86bluecobra said:
sometimes it stalls and will not fire by cranking it over unless you hold gas pedal on floor. .

Doesn't that usually indicate a very specific problem?
I can't remember what it was, but it seems that there was only one thing that would cause this behavior.

JRichker would be the guy to ask...

jason

HISSIN50 · Jan 20, 2007

Jason, AFAIK, it's too much cranking fuel. A bad MAP reading and/or ECT calibration are two that come to mind as likely causes. (I'm thinking that JR is wrenching on something this weekend - I haven't seen him in here yet).

It's also a common hot-start issue with larger (30+ pound) injectors and no tune, as well.

86bluecobra · Jan 20, 2007

HISSIN50 said:
Jason, AFAIK, it's too much cranking fuel. A bad MAP reading and/or ECT calibration are two that come to mind as likely causes. (I'm thinking that JR is wrenching on something this weekend - I haven't seen him in here yet).

It's also a common hot-start issue with larger (30+ pound) injectors and no tune, as well.

well i would like to hear more about the specifics of this problem i will wait for JR to return. its definetally not a 30lb untuned issue due to the fact they are stock.

86bluecobra · Jan 24, 2007

looking for a little help Jr.

ronburgundy · Jan 24, 2007

measure the resistance on your coolant sensor, it won't set codes if it's out. i could fax you a chart that shows the proper values.

ronburgundy · Jan 24, 2007

also check your fuel pressure while idling and with the key off. pressure should hold with engine off. if it doesn't then you have either a leaky injector or press. reg. to eliminate the reg. you have to plug the return line.

ronburgundy · Jan 24, 2007

me again, you could also have a sticky egr valve, in which case you'll need to replace it.

86bluecobra · Jan 24, 2007

ronburgundy said:
measure the resistance on your coolant sensor, it won't set codes if it's out. i could fax you a chart that shows the proper values.

I busted the coolant sensor a while back and i replaced it with a new sensor so i think that is ok.

86bluecobra · Jan 24, 2007

ronburgundy said:
me again, you could also have a sticky egr valve, in which case you'll need to replace it.

This is quite possible but the engine still has the miss when you disconnect the vacuum line to the egr. So there is no way it is opening at that point.

ronburgundy · Jan 24, 2007

doesn't matter what you do with the vaccuum hose, unbolt the egr from the intake, make a beer can gasket to block the ports, goop it up slam it together see if it's fixed.

86bluecobra · Jan 27, 2007

ronburgundy said:
doesn't matter what you do with the vaccuum hose, unbolt the egr from the intake, make a beer can gasket to block the ports, goop it up slam it together see if it's fixed.

will do. won't this adversally effect my fuel economy? This is after all our family vehicle. 92 F-150 FlairSide EXTCab.

ronburgundy · Jan 27, 2007

no it should'nt, egr's main purpose is to cut down nox emissions, nothing more.

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