Bank1 too rich and hard start on 99 5.3
08-11-2015, 03:45 PM
#1
Bank1 too rich and hard start on 99 5.3 My truck had a faulty fuel pump (before it went out it had a pinhole in the pickup tube internally so fuel pressure was a little low to start with).
Once I got the new pump installed pressure was back correct in the 55-58psi range so I retuned the MAF and VE which were previously tuned over lower pressure.
For the most part everything is good, but now I occasionally get a code for system too rich bank 1 and the fuel trims on that side are also fairly off on that side. Sometimes on a warm start it takes a long cranking time. I ran some Seafoam fuel treatment through the truck and it took a bit before the code came back. (it comes and goes on its own without me clearing it)
I'm leaning towards it being a leaking injector on that bank since I've already replaced the o2 sensor on that side with no change. Is there any good way to check other than pulling plugs and hoping to find one that is wet with fuel?
Once I got the new pump installed pressure was back correct in the 55-58psi range so I retuned the MAF and VE which were previously tuned over lower pressure.
For the most part everything is good, but now I occasionally get a code for system too rich bank 1 and the fuel trims on that side are also fairly off on that side. Sometimes on a warm start it takes a long cranking time. I ran some Seafoam fuel treatment through the truck and it took a bit before the code came back. (it comes and goes on its own without me clearing it)
I'm leaning towards it being a leaking injector on that bank since I've already replaced the o2 sensor on that side with no change. Is there any good way to check other than pulling plugs and hoping to find one that is wet with fuel?
08-12-2015, 03:19 AM
#3
TECH Senior Member
Bank1 too rich and hard start on 99 5.3 Leaky innector causes rail pressure to die off immediately after the 2 second fuel pump prime on key on... check for this.
08-12-2015, 08:27 AM
#4
I both swapped o2 sensors side to side and also put in a new one. No change.
I will watch for fuel pressure die off. The problem is intermittent which is my issue. It's not something I can easily replicate and until I try to start the truck I don't know if it's going to fire off correctly or kinda gasp then need a very long crank to start. The exhaust ends under the bed but on at least a couple occasions I've caught a glimpse of smoke once it started.
I will watch for fuel pressure die off. The problem is intermittent which is my issue. It's not something I can easily replicate and until I try to start the truck I don't know if it's going to fire off correctly or kinda gasp then need a very long crank to start. The exhaust ends under the bed but on at least a couple occasions I've caught a glimpse of smoke once it started.
08-13-2015, 01:47 AM
#5
My truck had a faulty fuel pump (before it went out it had a pinhole in the pickup tube internally so fuel pressure was a little low to start with).
Once I got the new pump installed pressure was back correct in the 55-58psi range so I retuned the MAF and VE which were previously tuned over lower pressure.
For the most part everything is good, but now I occasionally get a code for system too rich bank 1 and the fuel trims on that side are also fairly off on that side. Sometimes on a warm start it takes a long cranking time. I ran some Seafoam fuel treatment through the truck and it took a bit before the code came back. (it comes and goes on its own without me clearing it)
I'm leaning towards it being a leaking injector on that bank since I've already replaced the o2 sensor on that side with no change. Is there any good way to check other than pulling plugs and hoping to find one that is wet with fuel?
Once I got the new pump installed pressure was back correct in the 55-58psi range so I retuned the MAF and VE which were previously tuned over lower pressure.
For the most part everything is good, but now I occasionally get a code for system too rich bank 1 and the fuel trims on that side are also fairly off on that side. Sometimes on a warm start it takes a long cranking time. I ran some Seafoam fuel treatment through the truck and it took a bit before the code came back. (it comes and goes on its own without me clearing it)
I'm leaning towards it being a leaking injector on that bank since I've already replaced the o2 sensor on that side with no change. Is there any good way to check other than pulling plugs and hoping to find one that is wet with fuel?
It depends on what tools diagnostic equipment you have available.
I normally put a fuel pressure gauge on the rail(or where ever it goes)and use a scanner if it has the proper bi directional controls and do an injector balance test.
If the scanner does not have that capability OTC sells an injector timing box that you plug in to your injector, cycle to key to get max static pressure, then cycle the box for what ever ms you want and test it that way.
IIRC, depending on the engine, have an external fuel pressure regulator on the rail. Those can cause extended crank problems. Sometimes they leak externally(most common) but they can also leak(or fail to seal)on the rail side that bleeds fuel pressure off which results in an extended crank.
If it has CFSI(I think that's what it's called) the regulator is inside the intake. Those engines have their own set of problems....
"Normally" if its an injector bleeding off you will get smoke out of the tail pipe from the fuel puddling and an extended crank due to the fuel rail vapor locking and a misfire or running rough when it does start.