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Miss Fire under load

X

Xadous

New member
Joined
Aug 15, 2016
Location
Brisbane Queensland
Alrighty Gents

I have a miss fire in my 740 turbo and I can seem to shake it , We had to replace the turbo as it pooed its pants few months back and she drove great 10psi all day . Now for some reason I'm on the highway in 4th at 2500 rpm and she miss fires like the is no tomorrow and some times in 3rd . I have replaced the plus the leads checked for boost leaks and I'm at a loss . Its now at the mechanics and they cant find the issue either , Any help would be great I'm ready to burn it to the ground soon lol


TIA
Xadosu
 
I had this on my whiteblock. In my case it was the rotor and cap. Check plug wires too.
 
Fuel pump is all good Rotor Cap and plugs a ok , They recon injectors but i cant see how so i told them pull them out get a service on them and change the fuel filter what do you gents think
 
Xadous said:
Alrighty Gents

I have a miss fire in my 740 turbo and I can seem to shake it , We had to replace the turbo as it pooed its pants few months back and she drove great 10psi all day . Now for some reason I'm on the highway in 4th at 2500 rpm and she miss fires like the is no tomorrow and some times in 3rd . I have replaced the plus the leads checked for boost leaks and I'm at a loss . Its now at the mechanics and they cant find the issue either , Any help would be great I'm ready to burn it to the ground soon lol


TIA
Xadosu
Click to expand...

Is that plugs and ignition wires? I had a 1987 745 turbo with a recurring misfire under load which was eventually tracked to flashing over on one of the ignition wires at the terminals on the distributor. Seems like you have taken care of that? The one last component that you have not mentioned is the ignition coil.

Have you checked fuel pressure - that would be the ultimate confirmation of the fuel delivery system (with the exception of bunged injectors). What color are the spark plug insulators? Any evidence there of fuel starvation?
 
Brand of plugs?
Heat range/ number of plugs?
Gap of plugs? (Ok isn't a answer, numbers!)
Rotor and cap from Bosch or chinese Quality?
Jumped cam belt?
Year of car?
Fuel pressure checked or guessed?


Sorry my glass bowl is just in maintenance :-)
 
Does it only misfire under load? At what psi does it start to misfire?
Sounds like boost leak, CBV, or MAF issue.
 
That really does sound like a leak after the MAF, quadruple check...my brothers 940T was doing that and we could not figure it out for a long time, until the leak got worse. It was a silicone couple on the cool side of the intercooler, on the bottom where you couldn't see or feel it til a touch of oil came out.
 
Well Im picking it up from the mechanic he says its running to rich and will take 10 days lol which i call bull**** and im leaning towards the leak aswell Grrrrrr
 
Na mate they dont do that there . But it is running a tad rich i just dont get time to work on my own cars but now i have a new postion at my work i get weekends im going to take it back to stage 0 this weekend and work it out myself
 
Well a new thing it started doing on the way home is she miss fires when she is warm and then stalls out and I cant get it to start and it has a really strong smell of fuel give it 5 mins and I can start it again I cant win
 
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