Need help tbi fuel diagnostic!!

[DemonHunter]

I have an daytona 90 2.5 tbi and the fuel pressure drop after ~ 5 minute of driving.15 psi at idle,wot and normal driving. drop to 10 -5 psi 5 psi he start missing when driving.New fuel filter,new used fuel pump (same problem).tested with an other regulater maybe dosnt work too!
When I sqeeze the return line, fuel pressure jump to 45 psi easy.

many people say when you miss of gaz with those pump they broke.Is that true?

I need your advise im new to mopar world.

Thx alot
sorry for my bad english.

[DemonHunter]

more infos.

start acting bad after 5min at mid or wot.
if I close the ignition for 30 sec and restard, is good for an other 5 minute.

[john1320]

I had a similar problem- I replaced with a NEW fuel pump & filter.
Problem solved. DO NOT trust a used pump- trust me on this.
The cheapest pump I found was like $120 at Advance.

Hope this helps

[john1320]

Quote:

Originally Posted by DemonHunter more infos. start acting bad after 5min at mid or wot. if I close the ignition for 30 sec and restard, is good for an other 5 minute.

Bad fuel pump, brother.

[DemonHunter]

thx alot!!

tomorrow il take my pump from my old cavalier z24 and try to fit it in the daytona unit !

new pump here is 260$ can
or try to get one from ottawa.

[charger R/T]

what pressure is this TBI suposed to have I think they run a lower PSI then a turbo. In your post when you clamped the return line it jumped up to 45. You might have a bad regulator if the system pressure is suposed to be lower then this. When the pressure is low try tapping the regulator with something and see it it comes up. Old fords regulators would stick closed and psi goes high when bad mopar regulators would stick open and the psi would go low or have none.
Tim

[DemonHunter]

Ok thx

the z24 pump fit in the unit,and the strainer clamp on the pump so no need to seal the unit to the pump.

I hope the regulater can handle 14 psi with a 50 psi pump.

Now I need a new fuel tank rusted where the ring for the fuel pump unit goes.

[charger R/T]

If the system is to run at 14 psi and from what you wrote in post #1 its not the pump but a regulator sticking open.
Tim

[afsautoworx]

i think tbi's run at like 35 psi.....why in the world are u putting a z24 fuel pump in there. Are they the same pump? $120 sounds like a lot for the pump. Are u buying the whole sending unit too? Thought they were more like $60