Also when it does start I get no smoke or gas smell. Going to change out the fuel filter Wednesday just to rule that out since it is a cheap part and probably could use doing before the full winter fuel we have here. This car don't have a scan for the injectors and the spider is the original.

 

Those upstream O2 sensors look pretty good but there is no horizontal time scale. Can that be added and the graph zoomed out to see the frequency? Looking for 1-3 hz

The downstream sensor does not look right. It should be a roughly steady voltage level but somewhere between 0.45 and 0.75v not less than 0.1v. Did you say no codes? Look at that graph when the engine is cold to see if the downstream tracks the upstream sensors before the cat warms up.

Your MAF value looks low. The spec is 6.0+ g/s at idle. Me and my sidekick Les get around 6.5 g/s at idle. Is that MAF dirty? Any history of codes? Get someone to help you and see what the value is at the 1-2 gear shift under max acceleration. Have you looked at the wiring and/or reference voltage and gnd to the sensor yet? Can you directly measure the frequency out?

How does that IAT compare to ambient at idle?

What is the MAP value at idle and the baro pressure where you live at that time?

The hot ECT looks good. What is with a cold engine compared to ambient as a check?

Still need TPS and fuel trims (4 numbers, ST & LT - both banks)


George

 

Fuel trims will be a much better test than smelling for gas.

There are four tests for the injectors:

1 - The leakdown during the static fuel pressure test
2 - Measuring the coil resistance of each injector
3 - Using a noid light or an incandescent test probe to confirm power and ground side injector control from the PCM
4 - Using a pulse box along with a fuel pressure gauge to measure the fuel injection quantity for each injector
5 - Actually there is a fifth if you have a scope - looking at the firing waveforms/pintle hump

Forgot to mention in the previous post - still need cmp retard

If you maintain 55 psi during a crank, no start then the fuel filter is not likely your problem


George

 

Will get fuel trims tomorrow on the way home and.post them. Iat, ect are a match to the outside temp when cold. As far as I know the sensors are all original in it. I have not yet checked the wires and ground with working 12's and 7 days a week haven't had much time to mess with it. Also you are correct I get no codes and I scan for the in the morning when I get home and at night when I get to work. I have a graph with all of them with a time on it I will post on here. Did it the other way cause this one is a mess to look at.

 

If I am reading that funky O2 sensor graph correctly it looks like around one transition per second which is typical at idle.

George

 

I forgot when you get the MAF reading during a max acceleration 1-2 gear change we need the peak rpm


George

 

Hmmmm...this problem sounds very familliar..I have posted several times with the same symptoms...does this problem only occur days sometimes weeks intermittently...then you pull into the gas station and boom your stuck...r does yours always start..I usually let mine set for ..5 to 10 minutes and then it starts and runs fine...until nextime...and george how long should fuel pressure hold at the Schrader under perfect conditions...will it always bleed to 0 in a few hours or should there be some pressure indefinitely...good luck I'll be watching

 

I don't know on the fuel pump pressure question. A good pump does hold past the minimum 10 min but I doubt that I have ever check it past 20 min. and I am unaware of a longer duration spec. More importantly that behavior would have no relevance to how the truck runs because that is not an operating condition.


George
past

 

sorry for the delay haven't been home to drive it. It always starts for me. Just take a few time of turning it over to get it running. It does drop to zero over time. Got a new pressure gauge that I will be running into the can this weekend so I can see the fuel pressure at all times while running. See if that shows me anything more then what it does sitting idle in the driveway.

 

this is the fuel trim in a 15 min drive to work tonight. Tried doing a regular graph with all of them but they over lapped to where you could only see one solid graph so I split them um. Took the screenshot after I turned the blazer off. I thought it took one while running but must not of