Double post
Double post
Last edited by live2wheel; 07-02-2013 at 02:49 AM.
I've never seen that happen in a bypass type system, like GM uses. A friend of mine has used Ford Port injection fuel pumps from pick ups for years in TBI swaps, without issue.Originally Posted by gregs78cam
You're in limp home mode.
Check all connections to the ZIF socket, I would have used a DIP socket. I will check for continuity between the DIP socket itself and the trace as far away as I can trace it to be, to ensure that the connections is good.
Swap in a stock not modified ECM, if you can't find any problems with the ZIF socket connections.
There is ZERO reason that you should have that much fuel being injected, from the ECM side of things. The omitted sensors will not cause this issue at start up, probably cause drivability issues, however, issues that could be difficult to tune around without VSS.
The high fuel pressure will cause more fuel to flow, but shouldn't be so much that the engine will not start. Start and run rough yes, but not a no start condition. Check timing also, that can cause hard to start situations, that are more akin to what you describe, especially in limp home mode.
The man who says something is impossible, is usually interrupted by the man doing it.
At key on (fuel pump prime), not cranking, is fuel coming from the injectors ?
TOM
1994 3500 Dually , 502 (509) , 264HR , Edelbrock MPFI , PFI '7427
1992 S-10 434 SBC/Tremec - '7427
1986 Monte Carlo SS
1984 S-10 , SAS, 496/700R4/205 , D44/14BFF -'7427
1980 Z-28 496/700R4
1979 Corvette 496/700R4
1977 Olds 98 Regency 403/700R4
Ohhh... great question.
The man who says something is impossible, is usually interrupted by the man doing it.
I don't think so, that is what it's supposed to do... but he's never got it to start and go off. The blink once is a good sign.
Yes a small restrictive return line can raise pressure on feed line.
You could also be one of the millions out there with a fuel pressure gauge that sucks! If you can run the return through a 3/8th line to a gas can and check pressure that would tell us if the return has a restriction?
There are many fuel tanks with what looks like a return line... only to find it is a pin hole vent for CCP.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
I didn't read it as blinks the first time around.
Just to verify, at jey on, the CEL, will turn on, then off, then back on again, correct?
The man who says something is impossible, is usually interrupted by the man doing it.
When I first swapped to TBI in my truck, I had a nice Bosch inline pump (rated 50gph@50psi) that I thought would be easy to put on it, and work good. It was very rich, way over 13psi on the feed side. Changed to a standard TBI pump and everything was fine.
1978 Camaro Type LT, 383, Dual TBI, '7427, 4L80E
1981 Camaro Z-28 Clone, T-Tops, 350/TH350
1981 Camaro Berlinetta, V-6, 3spd
1974 Chevy/GMC Truck, '90 TBI 350, '7427, TH350, NP203, 6" lift, 35s
With key on and not cranking no fuel emits from injectors. SES blinks once then stays on. I turn on ignition then start to crank and immediately engine tries to start and revolutions increases and as that happens injectors are pulsing and as revolutions increase the injectors REALLY start to dump fuel squashing any chance of fire and revolutions slow down, stop cranking at that time.
unhook 1 injector at a time while tring to start it, it sounds like something going on with the map sensor or its wireing.
Turns out it was a bad temp sensor. I have to give credit to Bill at BinderPlanet for helping out over there too and for having this great spreadsheet to check voltages!
This issue solved... on to the next one......
D'oh!
Yeah when the CTS goes bad it reads -40C and ads fuel for choke like crazy! Data would have shown that...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
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