Hello,
I have a '92 E350 V8 with over 302,000km on her.
Just recently coming back from a trip (thank goodness, was close to home), the van started running a little rough.
I took a Voltmeter to it.
1. Key on, not running: 12.39v
2. Truck on, running: 14.60v

When I feather the throttle from/through idle to slightly higher idle, the voltage drops to between 9v and 10v. The dummy-voltage gauge on the dash drops to about the same.
If I try to hold it just above idle (before getting to the 'higher-idle' state), it will stall, as if carb-flooded - even though it's an EFI
.
When van is idling 'higher' at a steady rate (using foot to hold at higher rpm's), the engine will go smooth, BUT will seem to 'miss'/'hiccup' and do that every so often. No voltage drop is noticed on dash when this happens.

Please help, any advice would be good; I need my van for work!
Any questions, please ask and I will give detailed answers!
Thx,
R.

 

Engine block grounding. Try clamping a jumper cable from the engine block or the alternator bracket to the battery negative post and see if anything changes.

 

Okay, will do.
Just another thought: sometimes I run the fuel low (fuel gauge not working - going by odometer).
I put 10L in and that seemed to drop the severity of the 'hesitation'. Is that at all relevant? Maybe the fuel pump was sucking bubbles for a moment and it drew more amps? (I know, stupid suggestions..but you never know).

What, specifically, would cause 'engine block grounding'? A wire or something?

*note: I can totally follow technical replies, but I'm not a mechanic and may need to clarify a few terms or techniques.

Thx again!

 

I suspect impropper grounding of the engine block. The block has to be grounded. It is a metal strap that goes from the engine block to the body of the van. I think that on mine you can see it just under the passenger side windshield wipper motor. As you rev up, your coils need more current and your alternator is producing more, but the complete circuit is limited by how much current can go throug the grounding strap. If it is partially broken, that is your chocke point. By using a jumper cable to improve the grounding, you can verify if that is the problem.

Injector, coils, clogged fuel system could be another cause. Have you got any "Check the Engine" codes?

 

1. I will check that grounding as per your instructions.
2. Issues? LOL...omg, YES. IF you really wanna know, I just bought this van and have not had the money to get it checked out. All I know right now is that the brakes are f*kd (go to about 1" off the floor before slowing), the cruise does not work, AC need a recharge, fuel gauge no worky, and it burns about 1L of oil per 1000km. Thankfully, the tranny fluid seems to be holding up (but needs a change/refresh).
3. Check Engine light comes on after about 5min of driving. I have no idea what it's about

*Always happy for input =]
** No I'm not a bad owner for the above problems - I adopted them and just don't have the cash to sink in right this moment =]
All in good time!!

 

Can there be bad ground to EFI but decent ground to the starter?

Sixto
93 E150 Chateau 5.8 191K miles

 

Hi Ardee,
The easiest way to find ground problems (and the cheapest) is to connect a long, insulated wire to the negative battery post. Connect the other end to the negative lead on your voltmeter. Set the voltage scale to handle 12 volts and start probing ground points every where on the van. Turn on different electrical items and check the readings while selecting lower voltage scales. If you find a ground point with more than 0.5 volts, look for ground connections that have gotten corroded/rusted.

Older vehicles with that many miles are sure to have bad or even missing ground connections. With EFI/computer control, bad grounds can result in any number of erratic operations making troubleshooting a nightmare.

Good luck and keep plenty of scotch on hand! :-)
jim