Truck has got a miss

[rickgig]

Guys... don't know how to do this but to go into detail. By time you get to the end of this (if you bear with me) I will more than likely have to take it to Terry.

My radiator went south and I replaced it. Before this the truck ran ok (sort of, I'll detail that in a minute) and once the radiator was replaced it threw several codes. I blew them off as air pockets and other stuff due to replacing the radiator.

Cleared the codes and drove it to my buddies radiator shop (Forney) to have it flushed. On the way the truck ran good and I nailed it on 635 just messing around and it was great.

While they are flushing it it throws a check engine light... plugged the Diablo tuner in and it says "no codes" and I push clear trouble codes anyways and no more check engine light. Drive home (Frisco) and I notice it seems to have a miss and knowing I have about 40k on the high dollar plugs in it (IT-22's), I decide to change the plugs (NGK TR6's gapped at .35 and I run a 4lb lower).

Drive it today and I still have the miss. Now I think it's a fuel filter but no I replace it and still the same thing... could be my imagination but I thought it was worse although I could step on it but it sounded like one or two cylinders were not hitting. Before this if I tried to nail it it just bucked.

So my thoughts or questions are:
- Is this vacuum since before I jacked with the radiator it ran ok, sort of. I had noticed a slight miss before this whole thing but blew it off as bad plugs. The old plugs are perfect so I think something else had been going south. For something to come up as fast as this I am thinking I have missed something on the vacuum side of things.
- What do coil packs feel like when they go out? The odd thing is at low rpm is still kicks butt so it's got full spark until I hit about 2,700rpm.
- Bad gas? Like most everyone else I buy at the cheapest brand name place... Texaco is my last full tank (good or bad my father had a station while I grew up in the 60's). I've had issues with their gas before but nothing like this.

Any help is greatly appreciated. The L is my daily driver and I can't afford to be without it long. It's drivable as long as I don't want to play which does require discipline (had a Harley truch try to play, I did'nt take the bait and he just shook his head...)

Looking forward to seeing what y'all got to say...

[charlie]

If it was me... I would check everything close to the radiator. The MAF plug, cam pick up plug, crank pick up plug, vac leak, check the hose clamps behind the MAF
check the fuel pump resistor plug ...

Good luck
Charlie

[rickgig]

Thanks man... I've done that but will do it again. It just happened so fast and at the same time as the radiator so I really think it's something I have overlooked.

[L8 APEX]

Sounds like a coil pack or possibly fuel pump on an old truck.

[rickgig]

Sounds like a coil pack or possibly fuel pump on an old truck.

Whoa... fuel pump.

Terry, your comment reminded me of what happened this week too. Filled the truck in Rockwall and then I refilled it in Frisco since it was a quarter tank down. It took a few gallons but the fuel gauge only read 3/4's after the fill up which has never happened before. I have driven it about 40 miles since then with several start/stops and now it reads just under 3/4's.

Ya think the sending unit and the fuel pump could be related? It's odd that I have what appears to be fuel starvation and a fuel gauge that failing at the same time.

Oh yeah... Sort of resent the comment bout an old truck (jk) but it is an 01 with 124k on it.

[L8 APEX]

Both items go through the same connector but I haven't seen any connector issues with Fords only GM. Old trucks can loose one fuel pump and cruise fine but won't make any power. The hoses also get brittle nad split in the tank. You can buy a fuel pressure gauge from Vatozone for 40 bucks and pin it under the wiper and watch it. It should be 35 at idle with a 20psi rise at WOT. Can you make it miss by just power braking it?

[rickgig]

i'll give it a try later

[rickgig]

Both items go through the same connector but I haven't seen any connector issues with Fords only GM. Old trucks can loose one fuel pump and cruise fine but won't make any power. The hoses also get brittle nad split in the tank. You can buy a fuel pressure gauge from Vatozone for 40 bucks and pin it under the wiper and watch it. It should be 35 at idle with a 20psi rise at WOT. Can you make it miss by just power braking it?

Misses with power brake.

However I drove it today to Dallas and back and could get it up to 80 or better with gradual acceleration. Then if I gave it moderate pedal it would cut out. It seems more like the computer is dropping cylinders and not so much like a miss. I had a couple SHO's and there was a rev control so you couldn't dump the clutch at high RPM's and that is what this feels and sounds like.

My thought is vacuum. I did pull everything off to get to the drivers side plugs such as MAF, power tube and assorted vacuum lines. Got them all back on however I think I'll recheck the MAF sensor and the power tube connections to the intake. Can't imagine that I screwed that up but it won't hurt to check.

Addition to above:
I pulled the MAF and cleaned it for a second time, rechecked all the clamps for the air tube (AEM Brute Force... been running it for over a year) and took it for a spin. The idle is better. Before I could feel a miss, now it's smooth and I can power brake it without the miss occuring. So I am getting somewhere. The code it threw today was p0171 lean bank 1. I have a Preditor however I am not sure how to use it for diagnosing the problem.

Under moderate to hard acceleration it still tries to cut out.

[Ohmsby]

Coil pack is my vote

[L8 APEX]

If it misses under power braking have someone power brake it while you plug and unplug each coil pack or injector. That will tell you which cylinder it is.

[rickgig]

If it misses under power braking have someone power brake it while you plug and unplug each coil pack or injector. That will tell you which cylinder it is.

Nope... that is gone since I cleaned the MAF and checked everything from MAF back to the intake.

[charlie]

I was thinking about this on the way to work this morning. Have you checked all the plugs? If it got hot and run lean, you may have burned a plug.

Charlie

[rickgig]

I was thinking about this on the way to work this morning. Have you checked all the plugs? If it got hot and run lean, you may have burned a plug.

Charlie

Nope... didn't get hot at all. I replaced the plugs after I replaced the radiator.

I am beginning to think MAF. I have cleaned it 3 times now with CRC MAF Cleaner and it seems to run different every time.

Latest is yesterday... at idle it would miss again after I got rid of the miss earlier. Drove it to grab a bite to eat and while waiting for my burger, it idled as smooth as can be. Hit the road and moderately accelerated and there it was. It feels like a cylinder or two is being dropped much like the fart we get between gears from the boost bypass only it stays as long as I try to accelerate.

Gotta admit, I am really getting frustrated.

[L8 APEX]

Unplug the MAF and see how it runs.

[rickgig]

Unplug the MAF and see how it runs.

Run's the same with or without the MAF connected!!!

So... it sounds like I need to replace it?

Stock, after market, Cardone at Autozone or what?

I guess MAF could cause P0171 and P0174 codes (Too lean condition bank 1 and 2)?

[TXLIGHTNING]

Run's the same with or without the MAF connected!!!

So... it sounds like I need to replace it?

Stock, after market, Cardone at Autozone or what?

I guess MAF could cause P0171 and P0174 codes (Too lean condition bank 1 and 2)?You need to get a SCT programmer and SCT BA2400 from Terry and get rid of that Diablo dookie :tu:.

[rickgig]

You need to get a SCT programmer and SCT BA2400 from Terry and get rid of that Diablo dookie :tu:.

I hear that... but first I got to get it up and running right.

I am just looking for Terry to confirm my suspicion on the MAF and where to get one.

Autozone is 132.99

[L8 APEX]

What year is your heap? I have a 90MAF you can try or buy..

[rickgig]

it's an 01. I am heading over to a bud's place in mc kinney now to try his.

i'll let you know soon how it went.

[rickgig]

What year is your heap? I have a 90MAF you can try or buy..

Terry... it wasn't the MAF. At this point I am not sure where the problem is or where it went. Remeber the fuel gauge issue? It read less than 1/2 tank so I filled it. Starting running better from the moment I put gas in. Seemed to have a hesitation @ WOT when putting the foot down especially running at 65+mph.

Truck started to run awesome with no hesitation at all. Added a fuel additive just to try and dry up and water that I might have in the tank.

I am about to blow it all off as bad gas combined with error codes from flushing the radiator.

Threw a P0171 last night but I would get those every once in a while. To fix it I check my vacuum lines, tighten any hose clamps I have, clear the code and I should be good.

I apprecaite everyone's input and I am glad it wasn't major... just very frustrating.

Come spring I want you to tune this thing.