I did the 2.8 to sbc350 swap.Ecm,engine & wire harness all from a running car.Now I have everything hooked up.When I turn the key,I am not hearing fuel pump "prime".Engine does not fire.Did I miss something.Does my existing wires to the fuel punp have to be changed?Anyone had this problem?

 

Same year harness or different year. C100 might be different.

 

what car/year is the 350 ecm out of? if its say out of a 89-92 fbody then the ecm has VATS that will need to be defeated.

 

Vats may well be an issue for the OP , but Vats is not keeping his fuel pump from priming (Vats kills the injector pulse and starter only) .

 

Are you 100% on that, I thought on at least the TBI cars it did the fuel pump also. I distinctly recall not hearing it the one time I tripped it on my car. I've seen both answers. Including the shop manual says disables the fuel pump. Could definitely be other stuff but if the ECU was a vats computer he isn't going to get it running without handling that. If its a vats ecu its going to have to be defeated anyways.

Though on the 89 birds the power for the fuel pump engage at the relay was fed from the ECU, and the ECU received power for that circuit from the little wiring block passenger side beside the radiator in-front of the battery. This ran into the ECU bundle through the passenger fender. Not sure how varied year/year car/car that is but that circuit didn't go through the bulk head connector on my car. (the fuel pump power from the relay did) If that wire isn't getting power to the ECU then it could cause it.

Of course if everything else is right, the power for the pump is fed in the right pin on the c100 then you could always jumper the fuel pump relay and get it running, then trace the pump wiring issues down.

 

Also the new engine is it TBI or TPI?

 

Hey guys,The car was an 87 IROC motor and harness came from.The harness has some changes,smog pump has been eliminated.I know that shouldn't make any difference.I had the guy start the car before we made a deal.The engine is a Jasper engines class 2.It is TPI with a lot of performance parts which doesn't matter in this situation.The ECM is supposed to be the one in the car,I bought everything,ECM,harness,engine.All I know is car started before the V6 was removed which was sometime in March.I am figuring vatts should not be an issue,butt I don't know for sure.I have a 87 factory manual to go by for diagrams and such.I can tell you some of the wires I have compared between the 2 harnesses are same colors in same places but that was the power leads from the starter.I will check out the wiring for pump and such this weekend to see if anything is off between the 2 harnesses.I thought this swap would be simple,Boy was I wrong.This is just the latest issue.Thanks for the replys

 

Yea if the donor ecu/engine is 87 VATS should not be an issue. Maybe post the part number on the ECU someone could tell you for sure if it was indeed a 87.

Smog pump wouldn't have any effect there was no monitoring of it anyways.

Sadly your going to just have to go wire by wire.
Have you checked for any blown fuses, including the secondary fuse block that is behind the computer connector that is hard to get to (not sure the 87 has that 89 does)?

I would start at the ECU check all the hot wires and grounds there first. Did you use the relay original to your car or original to the donor for the fuel pump?
Do you get spark when you try to crank the car?
Buy some noid lights to see if your injectors are firing.
Check the fusible links you could of broken one as you moved the wires into place.
If you have access to the donor car look and see if it had any fuses in place that yours did not (I know the TBI has left and right bank injector fuses for example, not sure if the 2.8 did)

So when you did the swap did you have to cut/splice anything or did you simply plug the new c100, rout the wires to the ECU under the dash, connect the power leads and grounds?

Now one thought... this will not be your root cause but with the 2.8 fuel pump provide enough flow for the new engine?

This is the most complete list of wiring diagrams I've seen online http://www.austinthirdgen.org/?pid=19

 

http://austinthirdgen.org/mkportal/m...ine_wiring.gif
http://austinthirdgen.org/mkportal/m...ine_wiring.gif
http://www.austinthirdgen.org/mkport..._1987_C100.gif

Looking at the wiring diagrams between the two engines in 87, as well as the c100 diagram.

Check the inline fuse follow pin B1 on the ecu orange wire to find the fuse (this fuse I think is beside the battery and is just inline no block).

I don't see the fuel pump in the c100 for 87, so I'm not sure how that wire is routed on 87, where does the tan/white wire run from the pump relay? (if I had to guess off the diagram it goes with the ecu bundle to a connector that splits it out to the ECU feedback loop and then to the fuel pump, so there should be a connector beside the ECU make sure this connector pin out is right)

But if you look at the c100 it appears all were the same except for the L4. This should of been a simple plug and play swap looking at the diagrams.

 

That"s what I thought,a simple plug & play.Because of my work schedule I haven't been able to check for power at pump yet.I have seen numbers that say fuel pump will provide enough pressure.I think you are right about having to go wire by wire.To answer some questions.I didn't splice anything,pulled 2.8 and entire harness and disconnected ecm.Installed v8 plugged in harness at main bulkhead and connected ECM.I can tell you that the ECM with v8 says "AC DELCO reman" but it is supposed to be the one that was in the car.I do not have access to donor car.One weird thing that I noticed is now my "SERVICE ENGINE' light does not come on when I turn the key and crank the car.I also cant find the fuse by the battery,but I will keep looking.Nothing like that on either engine harness.I used the fuel pump relay that came with v8 but I am told same relay works almost all these cars so I am thinking about using the one from the v6 to see what happens.I WIll get this figured out.Thanks for the help.

 

Please help ,, 91 camaro 305 will not click, crank or start.
Question: if security light comes on and goes of after 3 seconds of turning over ignition, is it still possible to have a vatts problem causing the car not to start.
Ive got 10k in this car and cant drive it. everything was fine with this car for 10 yrs. it had an intermittent cranking problem , but always cranked.
i bypassed the the with module and everything seems fine but last time i cranked it, i gott a chatter super fast from the starter relay and now it wont crank.
i put a multimeter to the relay and dont seem to b gettin any power. Could the vatts cause this or the starter dead? or what,,, please help

 

doesn’t seem relevant to the original post. Why not search or start your own thread?

 

Give me a break I'm 62 years old trying to figure out all this technology. There may be somebody kind enough to help whether it's in the right thread or not.
Thanks for showing so much kindness

 

I was trying to help, this is a old dead thread

 

rapid chatter of the starter solenoid is either low battery charge or a weak connection, could also be a bad solenoid.

I would - take the battery to a store and have it load tested and charged if it is weak (assuming you don't have a charger).
Clean the battery terminals, and make sure they are tight when you reinstall it.
check down at the starter to make sure the cables are tight.
check the ground straps from engine to body, and the ground wire to the block from the battery.

If all that checks out, I would wire up a starter switch bypassing all the car's wiring (basically a wire from the starter solenoid to the battery) and see if the starter will engage like that, if it doesn't then pull the starter and have it bench tested.

Vats isn't where I would start.

You will probably get more answers though if you start a new thread.