Iv got a mazda B2500 diesel.its got a hard starting when cold,i changed the heater plugs were blown,saw a rocker broken so replaced that. sent injector pump for reconditioning,fitted back and want start??

Follow the link mazda b2500 torque sequence and settings cylinder head td bolts

There are a few things to check. Engine and transmission mounts replace any broken or perished . 1st gear selector shaft has a indent ball and spring to locate the shaft when in gear, check the spring is not broken. The gear box bearings may be worn giving the drive shaft to much end play. also check gear shift linkage is not worn.

which is the model?

Have you checked the glowplug relay.

when i used to teach mechanics many years ago i sent this disruptive student outside in the cold to change the spark plugs in my ford transit diesel ,after half an hour this clever little disruptive lad came back into the class and was totally demoralised because he couldnt find the spark plugs and everyone was laughing at him because they all knew it was a diesel and he thought he knew it all .Now you sure you dont mean the heater glow plugs ??

garages are not diesel specialists
take it to a diesel specialist repair shop for a proper diagnosis

Diesels are famous for hard start when cold. Consider having a diesel shop install an engine heater.

Try looking at the hot/cold switch.

Hey mate,

I have a Mazda B2200 from 1985, which has the same R2 diesel motor, and I had this same problem, which was exacerbated by the cold of winter....even here in a mild Melbourne.

Each time you turn the ignition on, the QSS (Quick Start System) powers up the glow plugs for about three seconds. This recycles again about three times, then.....nothing. The QSS reckons that you ought to have the bugger running by now!

In my desperation, I located the cable to the four glow plugs, and ran a second wire from the battery (+) via a push-button switch which I installed on the dash. This is my glow-plug BOOST circuit.

Now, when I want to start from c-c-c-cold, I push the button (with the ignition on) for about ten or fifteen seconds, which gives the glow plugs a goodly time to heat up the combustion chamber, and when I hit the starter, she usually fires up with a rattle, and a cloud of grey exhaust smoke.

BINGO!

(Of course, once the motor has warmed up, there is no need to use this BOOST circuit, for the combustion chambers are already hot enough to detonate the injected fuel.)

Have a go at it, as I know that it works!

John.

With regards to the above problem, I have just recently experienced the exact same thing with a 98 Mazda Bravo b2500 (this is a diesel).The symptoms were after driving over some corrugated dirt roads the vehicle would not rev over 2000 rpm and at that point would blow heaps of white smoke and misfire, but would idle beautifully and rev smoothly up to the 2000 rpm. Also noticed when vehicle was cold it would drive good for about 5-10 mins then symptoms would start again.

Fuel filters were changed, sediment trap cleaned,different fuel tried and checked all lines and system for air entry, problem still persisted. While checking injector pump lift pump pressure I noticed that the pressure would drop right off at the 2000 rpm, maybe a lift pump problem?? After consulting the workshop manual I found there is a small stainless steel thimble filter under the injector pump fuel line input union bolt, held in place with a small spring. Pulled this out to have a look and it was full of crud, cleaned it all up and put back together and have a guess what......goes like a brand new truck!!

Cheers