dondon69420

My 90 i6 5 speed 2w& is doing the same thing. I tested fuel pressure and have 32 psi koeo and 32psi with engine running thinking pump or regulator

KurtH

This did start once I got down to a 1/2 tank or so. I could try filling it up.

In my area, we have the gas with Ethanol in it. I would burn up at least a quarter to half a tank driving to where they sell non-ethanol gas.

Any suggestions on a reasonably priced, good enough quality Fuel pressure gauge? I have arranged to borrow a Vacuum gauge ... My dad still has one in his tool box .. last used over 25 years ago when we still had the '74 Dart.

memoniz

I happened to be in a Sears today and saw a fuel pressure gauge for around $39. I don't know if that is reasonable or not.

Chris_1

iTrader: (1)

That's a very good deal. I paid 60 for mine and that was a good deal

Chris_1

iTrader: (1)

Get a fuel pressure gauge. Also check your fuel pressure regulator (before you rebuild the entire truck - sounds like you're halfway there with all those new parts).

KurtH

I sure wish the shop I took it to checked the fuel pressure. Harbor freight has a fuel pressure gauge for $19.99. Anyone use the one from Harbor freight? I know it would not be the best, but probably good enough.

Now, just out of curiosity, dropping the tank is beyond what I feel comfortable doing. What is a rough idea of the cost to replace the fuel pump in at least one of the tanks should the need arise?

Chris_1

iTrader: (1)

I'd guess anywhere from 300 to 500 with the pump - depends how much trouble they have with old bolts, straps, connectors etc.
First check the fuel pressure. A new fuel filter, then some injector cleaner wouldn't hurt.
You need ; a f/p gauge, a vacuum gauge, and a voltmeter.
Then start testing things - everything is online somewhere - and find out what is malfunctioning and then replace that. That is what the garage you took it to should have done.
Or you could just replace everything and cross your fingers that it works.

Crock Pot

It's probably easier to lift the bed off. My son and I did ours (short bed) by ourselves in an afternoon. Just don't twist off one of those bed bolts! Each pair is configured differently and are not made any more. One of ours was corroded and we checked at Ford dealer for a replacement. They are like $20+ IF they can locate them.

KurtH

I strongly believe in pinpoint testing. A code means .. test that system, not blindly replace a part. My next purchase will be a fuel pressure gauge, I just need more free time to dig into this .

KurtH

I had a little bit of time, so I started the truck up. It stumbled pretty quickly and turned on the CEL . I pulled the code.. KOEO, 122 which is Throttle Position sensor below minimum voltage

I tried back probing the leads but only got garbage readings on my voltmeter. The haynes manual says the TPS on the 4.9 for 91 and up requires no adjustments.

I inserted the leads so they went through the small gap between the wire and the opening in the rubber seal of the connector until it stops. This worked for me a week ago, so there is either a problem with the wiring to the ECM or my technique is wrong. I started the engine with the volt meter attached, and got a different pattern, the engine seemed to rhythmically idle up, idle down, and repeat. I was watching this under the hood and i could see the engine moving, it would stumble, rock to the drivers side, then the idle would pick up, and it would rock to the passenger side.

while I was there, I used my vacuum gauge right off the throttle body and noted 20 in/Hg. To see if there is a leak, do you need to check the vacuum readings at different locations? I just do not know.