92 2600i started chugging under heavy throttle load- replaced fuel filter,fuel pump and had avpro rebuild ecm.Still missing under throttle load. just happened to be bumping around under the hood and wiggled the fuel hose out of filter to rail and the thing smoothed out and ran good as long as I wiggled the hose. I can start the truck it will run fine for about 30 seconds then problem occurs. If I shut the truck off and start it again runs fine for 30 seconds and starts missing again. Does anyone know what controls the fuel pump? I have looked online at the relay in the rocker panel drivers side,just wondering if there is more than that relay telling my fuel pump to give me more fuel. I have not tried to ground the fuel pump test leads yet to see if that works. I will keep you posted and thanks for any replys. SORRY FOR DRAGGING ON!!!

mazdaless in Alaska

 

That is the only relay I know of but you may also want to check your fuel pressure regulator.

 

What do I look for on the pressure regulator and where is it located?

Thanks

 

The fuel pressure regulator is located on the fuel rail towards the front of the motor and I don't recall how much PSI you should have when you take the reading to tell if it is too high or low. You should be able to get this information off of Autozone's website under there repair manuals.

 

I shorted the fuel pump test leads together. did not seem to make a difference.I did notice now when i hold the throttle lever open by hand at the engine it seems to run fine but by chance I pushed the switch, that the throttle cable cam comes to rest on at closed throttle, and the problem started again. This switch has a single wire running to the front of the motor along the valve cover and then into the loom. Do you happen to know where this wire goes? This is killing me!!

 

I am going to order a pressure regulator and fuel pump relay anything else I should order while I am at it? In rural Alaska with 1 mechanic and he has been swamped for months so at this point I will take any suggestions. The wife is seriously tired of walking in the snow!!

 

Did you find out the problem..?
I'm working on a friends auto 2600i P/u and it just went out. Turns over but not starting. I'm thinking it's the distributor or ECu.
I pulled the pump and tested it and it works fine, and has a half tank.
The shops around here didn't say that there was a relay, but knowing F/I there's got to be one somewhere. Another friend said that the ECU controls the pump.
Any answers.. Let me know.

E

 

to everyone and anyone that can help..i'll just add on to the post thats been here..i seem to have the same problem with most of you..my problem started 3 weeks ago when i started seeing white smoke in my tailpipe and then overheating..i found out that my coolant was leaking into my head piece.i took the risk and drove it for one day and i just stalled one day..and couldnt start the car, was able to crank i but wont turn over..i removed the head assembly myself and had it pressurized and found its beyond repair..got a fairly good used head assembly and reinstalled it after checking everything and pressured test..i swear that i got the timing correct with THE TDC marking on the main crankshaft, along witht the marking on the upper camshaft with the first piston on TDC..once i got everything on, I JUST WANTED TO TRY AND START IT..now correct me if im wrong guys.. i didnt hook up some of the other parts yet like alternator, radiator fan, radiator, water pump, power steering pulley , all the belts and theres no water circulating, i just wanted to start it..WOULD not having the rest of the parts cause a problem? if not, should i check the distrubutor, i allready checked the main ignition coil and it gives out a spark when i hold it close to the engine..WHAT about the oxygen sensor since its right there at the exhaust pipe, i ask only cus lots of coolant were going through there and was wondering if it got wet or it wouldve damaged them..my biggest question is THE FUEL PUMP..i dont know about the 1992 mazda..but i know fuel pump suppose to make a whirring noise when u turn the key to the ON position..it didnt so i pulled the fuel line and see if anything wold come out..NOW CHECK THIS OUT..no fuel come out when i turn it to ON..but fuel comes out when im cranking it..NOW IS THAT NORMAL? or is it suppose to ooooze out even if i dont crank it as long as its on the ON position..i'd like to hook up an OBD reader..but doesnt OBD only works on car thats made after 1996..pleaes help anyone..ANYONE PLEASE

 

I have a 1992 B2600i SE Cab Plus with only 54800 miles on it. Three weeks ago, as I was driving, it just died. I was able to restart it, but with, barely enough power to get home. Back in my yard, it would start, but die as soon as you touched the gas. Eventually it wouldn’t even start. I changed the firewall mounted gas filter. Nothing. Following the shop manual, I then changed the Fuel Pressure Regulator. Nothing. Suspecting the fuel pump, I borrowed a fuel pressure gauge and, using the underhood jumper plug, I checked fuel pressure at the filter outlet. The book calls for 60 to 80 lbs. Mine went to 70 lbs with no bleed down after 5 minutes. I still suspected the fuel pump, but went internet hunting. On this forum I found out about AvPro. I emailed them, and then pulled my ECM and sent it to them. When I got it back, I installed it and hit the swtch. NOTHING!!! Then I remembered that I had removed the negative cable from the battery. Hooked it back up and twisted the key. MY TRUCK RUNS!!!! She fired up like it had just come down the assemble line.
Filter cvost was $40. FPR cost was $130 (my brother knows the manager of a Car Quest. The FPR lists at $330.) AvPro got $160 to overhaul the ECM and send it back. I highly recommend them.

 

I have a 1993 Mazda B2600i It will Idle at 2000 rpm when you step on the pedal it will go to 500rpm and almost stall if not stall any help would be great