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camerontech, Auto Mechanic
Category: Mazda
Satisfied Customers: 480
Experience:  diagnostic auto tech
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1999 mazda b2500 2.5l automatic. fuel pressure is 70 psi,

Customer Question

1999 mazda b2500 2.5l automatic . fuel pressure is 70 psi, new plugs and wires, new crank sensor, new iac, timing at 10 btdc. Cranks and idles, sputters and sometimes dies when accelerating. Idles dtc. worse when cold. any ideas? tps? EGR?
Submitted: 1 year ago.
Category: Mazda
Expert:  camerontech replied 1 year ago.

Hi there,

My name is ***** ***** I am a licenced diagnostic technician with over 20 years experience.

I will do my best to help you with your automotive problem. Please remember, I cannot see, hear or feel your vehicle which can make diagnosing very complicated and some vehicle require extensive diagnotics that require certain diagnostics computers that can not be done over a computer or phone.Please be patient as I am not online 24 hours a day, as I do work, but I do check my page every day.A positive rating is always appreciated for my time and knowledge to help you with your problem.

Have you performed a data stream check on this yet? to see what the sensors are doing when accelerating.

It sounds like either the tps has a flat spot in it, and you will need to do a voltage sweep to test it.

Or the mass airflow sensor is dirty or faulty. Regarding the mass airflow sensor, you can clean it to start with with a q-tip and some brake parts cleaner, but please be gentle as they are very fragile and can be broken easily.

Again the mass airflow will need to be tested with a scanner and monitored while snapping the throttle.

Also. please check for a cracked air snorkel tube because it there is a crack present, it will give bad maf readings as well.

If its worse when cold, make sure your coolant sensor is reading the right temperature.

A scanner will be necassary to test these items, but a visual check of the air intake tube and cleaning the maf sensor will be a good start.

LEt me know if i can assist you any further, and i apppreciate any positive ratings!


Customer: replied 1 year ago.
I replaced the TPS, Cleaned the MAF . still has same issue. cranks, idles, but when you press the accelerator, it stutters, and sometimes dies. doesn't matter if it is in park or in gear. once it gets past the stutter it runs great.
Expert:  camerontech replied 1 year ago.

Is it storing any codes at all?

we have to determine if this is a fuel issue or ignition break down.

please check for codes and lets do a fuel pressure test snap test.

Is the fuel pressure dropping when you accellerate? 35 to 65 psi is optimal. but if its dropping when you snap the throttle we have a delivery problem.

do you have access to scanner to watch data stream when cutting out?

also, did you see if the snorkel air tube was cracked?


Customer: replied 1 year ago.
problem located and repaired, not related to earlier suggestions.. started back with basics. found 2nd set of wires not on proper coil towers. located problem before the last suggestion. your info did not help. please refund
Expert:  camerontech replied 1 year ago.

i cannot give a refund as i have not recieved any payment yet. you will have to talk to customer service and they will be glad to help you.

Regarding info i gave you...

you did not give me the proper info,

When you say that you installed plugs and wires, i assume that you have installed them properly, and i take this into consideration.

So the problem is with your initial repair, not with my diagnostic suggestions.

Like i said in my first message i cannot see your vehicle, and you should have said this problem started after you did your initial repair.

When i do repairs and install wires, i install them in the correct place.

you should have asked for correct ignition wire routing diagrams before attempting repairs that you cannot do correctly

We are licenced experienced tech on this site that need proper initial info to help with your problems.

have a great day!