Engine starts and shuts off?

TIMP1961

MEMBER
1996 FORD RANGER
2.3L
4 CYL
2WD
AUTOMATIC
148,000 MILES

The truck sat for about six years. Did the following steps:

1. Before trying to start I removed the fuel tank, cleaned it out and replaced the fuel pump assembly, flushed the fuel lines before and after the filter (removed filter for line flush). Replaced fuel filter.
The engine did start but barely. And ran rough.

2. Replaced fuel injectors, spark plugs and wires. They were horrible; fuel injectors weren’t too awful bad but wanted a clean slate. The engine starts after a couple turns revs then dies. Can keep it running by feathering throttle. When warm enough it pulses to about 3,000 and down to almost stall the revs again.

3. Replaced IAC old IAC was original and a bit rough. The engine runs a bit smoother but with the same 3, 00 rev and shuts off.

6 Replies

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

Hi,

When you had the IAC removed, did you check to make sure there were no carbon deposits where it mounts? Also, have you checked for vacuum leaks?

You could have a vacuum leak at any point. Also, the EGR could be stuck.

Do me a favor, first check for a leak, specifically around the PCV.

Here is a link that explains how to do it:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Also, let me know if you have done anything with the EGR valve.

Take care,

Joe

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Saturday, October 15th, 2022 AT 10:17 PM

TIMP1961

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4 POSTS

Hello Joe, a couple of notes.

1) The mating surfaces to the EGR were clean and a new gasket was installed after the injectors were replaced.

2) I checked the fuel pressure as well.
With the key on engine off 0 PSI.
With the key on engine started 40 PSI.

Pressure holds when the engine shuts off but slowly bleeds down.

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Sunday, October 16th, 2022 AT 8:29 AM

TIMP1961

MEMBER
4 POSTS

I just checked the vacuum pull on the EGR and the fuel pressure regulator. Both hold vacuum.
The PVC cleaned and free moving and engaged in place.

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Sunday, October 16th, 2022 AT 8:59 AM

JACOBANDNICKOLAS

MECHANIC
109,758 POSTS

Hi,

That doesn't make sense. You should have pressure as soon as you turn the key to the on position. The pump should prime. Do you hear it turn on?

Based on this info, it sounds like the only time the pump gets power is with the key in the start position. Is that correct?

I realize the fuel system isn't fully actuated until the profile ignition pickup provides a signal, but there should be a second or two of priming when the key is turned on.

By any chance, do you have a scanner, or have you had the computer scanned for diagnostic trouble codes? If you do have a scan tool, can it read live data? I'm questioning a few things. The idle issue and rough running may be the result of a faulty engine coolant temperature sensor (ECT). The sensor measures varying engine coolant operating temperatures, providing the information to the Powertrain Control Module (PCM). The ECT signal is used to modify ignition timing, EGR flow, and air/fuel mixture. Maybe it is dumping fuel or the opposite.

Let me know if you have a live data scan tool. Also, let me know if any codes have been retrieved.

Take care,

Joe

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Sunday, October 16th, 2022 AT 7:40 PM

TIMP1961

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4 POSTS

The fuel pump is charging with “key-on”. The charge cycle can be heard and shuts off as expected.
I checked the MAF cleaned it with appropriate spray and reassembled. The same issue occurred on the start attempt.
I have a Ford CD with all the service manuals, so I dove in on each system sensor and its operation. I found an interesting blurb on the positive crankcase vent system and how it’s tied to the MAF. I rechecked all the vacuum lines and found that the PCV had come disconnected under the intake manifold. Probably from the engine vibe, it may not have been pushed on the intake fitting completely during injector replacement.

You know that feeling you get after you find something that just makes sense to solve the problem?
I turned the ignition on at it started and revved just as before... But then it slowly dropped to a nice 1k idle. Holy smokes.
It purrs. I realized I may not have needed all the sensors, but it was worth it, I did see a difference with each replacement step I made. Also, I did find erratic readings on the TPS, so I replaced it after checking it against the new part.
Anyway, thank you for all your help. It was great to have a sounding board to bounce information to and get knowledgeable responses! Much appreciated!
Now on to the transmission shifting issue. Thanks again!

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