Stalling after start

[Paraphoe]

Alright guys, help me try to figure this one out. Last week I seafoamed my X, and was thrilled with the results, as I explained in this thread. I also added 1/2 can of seafoam into my gas tank after and since I've been having issues with stalling and the engine throwing codes. Throughout the week, when starting the truck, it's acting like there's a vacuum leak. It'll kick off and then sputter to a stop and stall out. I'll have to step on the gas immediately after starting it up to get the RPMs up, and then throw it into drive and it's fine. A lot of times it doesn't really have an issue when started hot, but cold it's stalling, which is strange.

I was convinced it was the seafoam in the gas causing a lean fuel mixture issue of some sort (see codes below), but I've since polished off the fuel and re-filled the tank, and the problems persist.

Today I cleaned the hell out of my MAF, thinking I fouled it with oil (as I also cleaned my filter last weekend) and disconnected the battery to reset the computer with the new tank of gas. Still having issues.

I've jotted down the codes below that the truck has been throwing. I found what some of them are, but the vast majority are a mystery.


P1234 – Fuel Pump Driver Module off-line
P0174 – System too Lean (Bank 2)
P0171 – System too Lean (Bank 1)
P0040 – ?
P00C0 – ?
C0490 – ?
U0C92 – ?
C20C8 – ?
P0070 – ?
P0734 – ?


If anyone can help me identify the remaining codes or offer any advice I'd appreciate it. It's behaving like a vacuum leak, but I'm not sure a vacuum leak would cause these codes and be something that behaves differently with a cold vs. hot engine.

Thanks in advance...

 

[mechjames]

P0040 Upstream Oxygen Sensors Swapped From Bank To Bank
P0070 Ambient Air Temperature Sensor Circuit
P0734 Gear 4 Incorrect ratio

and the rest don't exist. my guess is your engine computer is corrupt. I had this happen to my 94 explorer and my friend's 94 mustang. Have you tried resetting the computer since you cleaned the MAF sensor?

The other codes don't follow normal code styles. Leads me to believe the ECU is corrupt.

 

[mechjames]

although I could be wrong:

http://racingtec.sg1009.myweb.hinet.net/DTC.pdf
EDIT: http://westers_garage.eidnet.org/OBD2 Trouble Codes.pdf

P00C0 is listed there but no definition,
C0490 is listed on the GM trouble code site as C0490 Steering column lock solenoid circuit malfunction

other ones don't seem to exist. I'm also leaning towards the code reader being hooped.

 

[mechjames]

also, check your grounds for the battery, pcm, etc. a bad ground can cause a lot of weird problems.

 

[explorer06420]

hey my 93 does the same thing except for my engine light is NOT on... not sure what it is either and new to the site but when i start the truck in the morning if i dont step on the gas it will like choke it self to stall... if you have gotten any suggestions about yours please feel free to share thanks

 

[mechjames]

hey my 93 does the same thing except for my engine light is NOT on... not sure what it is either and new to the site but when i start the truck in the morning if i dont step on the gas it will like choke it self to stall... if you have gotten any suggestions about yours please feel free to share thanks

Try to clean your mass air flow sensor in the intake tube by the airfilter. Electronic parts cleaner or even Mass Air Flow sensor cleaner if you can find it.

Its pretty common for a MAF sensor to not report right and not throw a code until it doesn't work at all.

 

[explorer06420]

oh ok thankyou i will try that and let you know if that works thanks again

 

[Paraphoe]

Mech,

Do you really think a bad battery ground could be the issue? Funny you mention that, because I just cleaned out my terminals, and the negative side won't clamp down tight enough on it's own to stay on, so I have some copper wire on it and it's clamped down on that, but I'm not convinced the ground is that good. Even still, how would something like that cause stalling out?

 

[mechjames]

swaying voltages can cause the ECU to run weird. Even really dead batteries in fuel injected cars can cause weird problems, like gauges acting up, lights blinking, etc. Usually its a bad positive connection that causes a solenoid just to click and not start a car, but a bad ground can cause some weird things to happen sometimes.

You could try shimming the terminals as a temp solution, or use a pair of pliers to try and compress the terminal so it fits on the battery tighter. Then reset the computer and try again.

edit: Vehicles could run off alternators in the good ol days before fuel injection, but with lots of electronics in todays cars, bad battery connections can be a problem.

 

[Paraphoe]

Gotcha. I just ran the truck and it was even more difficult to start - I really hadda jump on the gas quick. Threw 6 more codes, only one I remembered was P1776.

I'll tighten down the battery terminal tomorrow, anyone have any other ideas other than that?

 

[mechjames]

P1776 is:

Chrysler Solenoid Switch Valve Latched in LR Position (this is a transmission issue which may involve replacing the valve body and solenoid pack; on some models there is a TSB on this problem so be firm with your dealer / Chrysler).

Are you sure no one dropped in a caravan engine in your ford? lol just kidding. Seems like the computer is definitely making up codes that doesn't belong to your truck (like the GM specific one I found above)

good luck. hopefully the battery terminals fix the problem.

 

[mechjames]

Jason,

Any luck with the battery terminals today?

 

[Paraphoe]

James, nice timing - I was just pulling up this thread to post. I believe I just solved the problem. When I started the truck this morning I got out and gave a listen - I could hear a sucking noise from inside that I knew wasn't supposed to be there. I was convinced it was a vac leak.

So, I just got home from work, popped the engine cover off and traced the IAC tube back to the engine where it enters the little rubber boot. Sure enough, the boot was partially torn and roughly 1/3 of the IAC tube end was out. This had to be from me pulling and tugging on the IAC tube to get the t-joint in for the seafoam. Anyway, I wriggled the boot back on and zip-tied it in place. I haven't taken the truck out for a ride yet, but I just started it, and it was flawless, and my idle was higher than it's been in months.

The codes may come back, I'll have to drive it around a while and see what happens, but I think this one can be filed in the "mystery solved" and "problem fixed" folders.

 

[mechjames]

Hopefully it works good! I think the batteries must have been low in the code reader to get other manufacturers codes showing up though.

But yea vaccum leak means system too lean, and your code reader did report that. So it was partially right!

 

[Paraphoe]

Just an update, drove it twice last night to the firehouse and all the way to work this morning without the CEL or any codes popping up.

 

[explorer06420]

good to hear...... glad u got that fixed... mine still needs tons of work lol