Help!

Did you put a gauge on it?

I deal with new parts that don't work somewhat often at work. The first place I look for possible cause is recent changes. Your recent change could easily be causing the issues you're seeing. A test under load would be useful, even just driving around the block.

You wouldn't happen to be in San Antonio, would you?

Check for a vacuum leaks.
Once, I fouled up a upper intake reinstall which resulted in a huge leak that didn't show up until the #8 spark plug fouled from too rich gas. The car bucked , stalled, ect. no codes either.

Brent odom said:

I think im just going to go ahead and replace the fuel pump again and go ahead and put a new fuel pump relay.

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^^^Hopefully this doesn't come across too hard. ^^^THIS is "parts changing" at it's worst. IF this problem is related to fuel pressure it is very easy to test for without having to buy parts and going through all of the work installing them.

Has the battery voltage been monitored while driving? If not there's a real missed opportunity to "hit one out of the park".

IF you just feel there's a part that needs to be replaced, then what about the alternator? Has it been tested for correct output (bad diode)? No excuse to skip this step as almost all auto parts stores will test for FREE.

What about the battery? Does it hold a charge? Are the battery terminals clean and tight? What about the grounds around the radiator core support?

Bottom line. Today's cars simply will not run right without a strong battery and charging system. Cut corners here at your own risk.

What has been done to rule out excessive EGR flow? Want a simple low cost test? Just remove and plug the vacuum line to the EGR valve. Does this improve symptoms?

Want to "KNOW" if your problem is related to the EVAP system? All you have to do is disconnect and plug the EVAP vacuum line and see if the symptom improves. It will cause a new DTC but that's OK as it's from the test.

What about the MAF sensor? If the MAF sensor were to suddenly report a much lower flow than actual, guess what? It would act just like the motor wasn't getting any Fuel......

Same thing for the fuel rail pressure sensor (FRPS). If the FRPS is in error it could "cause" an apparent lack of fuel.

Still think the problem could be related to the fuel pump relay? Monitor the voltage at the trunk mounted IFS shut off switch. IF this problem is related to the Fuel pump relay (CCRM), then it will show up as voltage drop at the IFS switch. IF the voltage doesn't drop at the IFS switch there's no way the CCRM is at fault. Problem only happens while driving? Then get a long piece of scrap wire and put the Volt-Ohm meter (VOM) in the passenger's compartment by lowering the rear seat.

Finally it seems to me rather than replacing yet another fuel pump on a guess, why not measure the fuel pressure? Even better. Why not measure the Air flow (MAF)?

Do you have a windows laptop? Do you have $30? Consider getting an ELM327 USB dongle with the ForScan software? Very easy to graph fuel pressure and MAF flow while driving. Then you will KNOW what is changing the moment the problem happens.

Expect a steep learning curve on how to use an ODB2 monitor to effectively solve problems but this is soooooooo much superior than changing parts on a guess. At the least wouldn't it be better to have an idea what's wrong before starting a repair?

ForScan ODB2 scanner w ELM327 USB

OHP Ford ELMconfig USB device 500kbit/s ELM327 compatible interface with MS-CAN switch for Forscan FoCCCus Mazda OBD2 diagnostics

View: https://www.amazon.com/gp/product/B01F0GVBWY/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A3HT224M59LA1Cie=UTF8&psc=1&smid=A3HT224M59LA1C


http://www.forscan.org/

^^^ That's the right answer.

Either way you go, good luck and keep us in the loop!

So you don't have $12 bucks for a budget Volt-Ohm meter (VOM)? Most of the monitoring suggestions given didn't involve using anything more than a VOM and a piece of wire.

You don't have a buddy or family member with a laptop? What about a desktop? Not as mobile but if things are really that tight.....

It really doesn't take much of a laptop to run the ForScan product. I have a refurbed unit for NewEgg that was right at $200. It doesn't take a 1000-1200 laptop.

You don't have an auto parts store near by? Almost all will test alternators and batteries for FREE.

Most auto parts stores will rent tools for free. Fuel pressure testers and the like.

You don't have $30 for the USB dongle? Remember that you CAN monitor all of that and MORE with the ForScan tool. In fact the Forscan tool will put you on almost EQUAL footing with the professional shop.

In fact take the $$ saved by not replacing the fuel pump and expensive CCRM relay you were about to replace. Or send the long tube headers and MSD coils back.

It really is "possible" to fix cars with not much more than hand tools (I don't have much beyond hand tools). BUT a decent VOM meter is a required tool to work on TODAY's cars. But having better tools can make the job easier/faster.

My DD is up to 225k miles. I fully expect to get another 100k out of her.

Don't buy a laptop just for this. You could get a scanner cheaper than that.

Just drive down to the nearest auto parts store and have them pull codes. When it wouldn't start while hot, did you check voltage and fuel pressure?

robertsa said:

Don't buy a laptop just for this. You could get a scanner cheaper than that.

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At the risk of starting a flame war, can you give some examples? Just to make sure we are talking about a stand alone scanner and not an inexpensive READER.

Most people these days already own the PC/Laptop. So in that case we are comparing the cost of a dedicated scanner to a $30 dongle. Which is less than the cost of a budget code READER.

But it's a fair point that IF the cost of the laptop itself has to be factored in, the analysis isn't so clear cut. But if $$'s are an issue a new laptop isn't required. A $200 NewEgg refurb unit will do the job. Also consider that the laptop could be used for other things.

An Actron CP9660 has a list price of $117.95 which is about the minimum unit I could recommend. However the ForScan software beats the budget Actron in some key areas:

• Ability to monitor and GRAPH multiple PIDs at the same time. The Actron displays a single PID value with no graphing.
• Ability to access Ford specific PID's. The Actron supports the generic ODB2 PID's.
• Ability to save the raw monitor data and process with external graphing tools.
• With an extended license, ForScan is capable of reprogramming PATS and other non PCM based modules.
• ForScan supports bi-directional PCM support. Which means that ForScan can command the PCM to turn on fans or close EVAP solenoids. A HUGE advantage when working on these systems.

Before I recently upgraded my ODB2 scanning ability with the AutoEnginuity suite, I used for years a single line Auto X-ray scanner/reader. So I know first hand that it's quite possible to solve many problems with such a tool. I also know what a difference it made when trouble shooting to have access to operational PID's even if only the generic ODB2 set.

But the single line Auto X-ray always frustrated me because it couldn't access some of the Ford specific PIDs. EGR duty cycle is one frequent example (DPFE flow).

I get it. The laptop based tools aren't for everyone. The dedicated purpose scan tools are far more portable and rugged. Most are easier to read in the sun light. The laptop is a total PIA to try and use while driving the car. Perhaps the biggest disadvantage of the ForScan solution is that it works only on Fords (That's why I spent the extra $$ for the AutoEnginuity product).

Bottom line. Having access to ODB2 operational PID data (of any kind) is a game changer. It's one of those things that after one learns how to use it you will wonder how you ever fixed anything without it.

Brent odom said:

Yes, 38 psi, it could be a possibility that the fuel pump and filter could be bad, but they have 600 miles on them both.

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Just wondering HOW exactly was this 38 PSI measurement was taken? Why is this important? Because if taken with an external gauge at idle then this fuel pressure is way too high. At idle an external fuel pressure gauge should read 28-32 PSI.

What's one thing that could cause a high fuel pressure reading at idle? How about a disconnected or leaking FRPS intake vacuum reference line.

If on the other hand the fuel pressure reading was taken from the PCM, then how do you know that the fuel pressure rail sensor is giving good information unless it's cross checked with an external gauge.