tfitzy16

I am looking to have a second pair of eyes look at my engine swap wiring. I swapped a 1987 2.8L out for a 1991 5.7 tpi with complete engine harness uncut with computer and witnessed it working before I purchased. When I rewired the things in the c207, c100 and almost eliminated the c221 connectors everything was soldered and heat shrinked and/or repined. The car will crank but I get no fuel pump noise. I have checked the fuel circuit as well and have found no power to the orange wire on the fuel relay or the fuel pump fuse. I installed the VATS bypass module and ran both 30hz and 50hz signal through the same wire to the blue VATS ECM wire in the c207 connector. Is that how it is suppost to be installed when your unsure which signal it wants? I also tried individually each signal and it still didn't allow power to go to fuel pump.

The c207 connector had a red and black wire I could not find out where it needs to go on 91 diagram it says Fuel Pump Prime Connector? Is this needed? From the 1987 C207 connector I have removed the pink and black wire from pin G to install even injectors wire from C221. I then needed to do the odd injectors wire which was in slot D in the C221 connector and moved it to slot B in the C207 connector to mate with the 91 pink and black injector wire. That's how the red and black wire in slot b got removed.

Other things I have rewired is a brown wire in the 1987 dashside c221 connector slot C I ran to the drivers side c100 connector slot G8 to mate the 1991 engine harness side G8 Brown which is coolant fan relay.

I also crossed over the tan and white wire from 1987 c221 connector near ecm to the G4 slot on the C100 connector to mate with the 1991 engine harness G4 which is fuel control. I have shop manuals for both years and have tried my best to cross all differences off a list of differences between the 91 engine harness and the 87 dash harness.

On the wire diagram it shows a inline fuse #2 (cant find its location) I have no power coming from that wire and I am trying to trace that back and find out why. That's where I am at now and could use another opinion.

tfitzy16

So when I apply 12v to the red connector it enables the fuel pump circuit. What harness connects to this C145 connector? Why the **** did I not get this from the guy who sold me my engine and harness. Any pictures of what plugs into this connector would be very helpful! Please and thank you. engine is a 1991 camaro L98 5.7L

Pocket

iTrader: (24)

That connects to the battery cable for 90-92 TPI cars

A work around is to cut the connector off and extend both wires to a 12v constant point. Older v6's had a power distribution block near the battery

tfitzy16

Thank you for your input pocket. I did notice my v6 had a junction block that the v8 doesn't use. I prefer the junction block but I understand now why not having that jumped to battery was not supplying power to circuit. so we got that C145 connector all figured out. Just wish I had the other half of it instead of hardwiring but is what it is.

Everything is working fine except injectors now. Checked fuses. I am getting fuel and spark. I checked all injectors by ohms testing and they are between 15~16 ohms. When I disconnect a injector plug on each side I test the volts with a multimeter and I get the same voltage on both wires in the connector 12.7V on both sides of the engine. The schematic makes it look like the darker wires (blue or green) are ground wires for the injectors and the pink and black wires are the "hot" with ignition on wires. Am I suppose to be getting voltage on both sides of the connector when ignition is "on" when its not plugged into a injector? Or did I goof when I rewired the injector wiring to accept the 91 engine harness? I paid very close attention to odd injector wires and even injector wires and making sure they match up with the 87 harness. Could this be a ignition module problem? I may have bumped it against the firewall once or twice when I installed the motor. I may have to get it tested repeatedly to ensure it consistently passes tests on auto zones diagnostics board. Had a failing ignition module on the v6 once before. Any help would be appreciated.

tfitzy16

could rly use a few recommendations. tried to start today and first crank it didn't start. checked some wires and pulled on some things near distributor and she cranked right over. ran for about a min and I shut her down. then tried to refire and wont start. took ignition control module down to auto zone and it failed 9/10 test sessions. bought a new one and installed but still no start. checked injector connector while cranking and test light dims but cant rly tell if its blinking like manual states it should. Thinking ignition coil could be the culprit? still need confirmation on if I should be getting 12.7 Volts on both sides of the injector wiring. Also not getting code 12 when grounding aldl? Is that a sign of anything? Any ideas are welcomed. Felt so nice to fire it up and rev it alittle!!! timing sounded spot on too. rpm gauge reads around 500 rpms while cranking. seems normal.

tfitzy16

So I have been trying to find out if ecm is bad or not. I measured the resistance from ecm to ground and found it to be rather high. ~1000 ohms. so I connected a jumper from the ecm case to ground. the car started the very first crank and ran perfect. so after about a min or two I turned off and immediately tried to restart the car. nothing. I tried several times and still nothing. so then I measured my injector grounds at the ecm and found two were around 15 ohms and the other two were rather high. The injector grounds I measured where on pins A12, D1, D6 and D7. These are in ecm connectors C1 and C2 and are black and white wires. after grounding these with jumpers making sure not to touch other wires I tried to start the car. Nothing after many attempts. I think next step is im gonna have the new ignition module checked again and make sure im not destroying them by having something wired wrong going to it. I also replaced ignition coil. EVERYTHING with the ignition system is new. I am out of things to check except for ecm. Did another test to the injectors. I disconnected all of them. Checked positive wire (pink/blk) and get 12.9V and checked ground wire and get 0V only when all of the injectors are disconnected. After one injector is connected volts run through all injector connector wires. I find this to be normal as the green and blue wires are the wires that go to ground when engine cranks and when the power wire voltage for the injector is connected to the injector it energizes the entire ground wiring as it is in parallel. So I have my problem narrowed down to the VATS bypass not being consistent which is what im trying to work out with the manufacture now. The ignition module failing or bad grounds and/or bad ecm grounding switch. Any insight would be appreciated. Its looking like ill be driving the winter car until next summer...

tfitzy16

So ive come to the conclusion that my ecm is probably bad. It is a remanufactured computer and even tho I have rewired my dash harness to accept the engine harness and computer the computer is outputting two weird voltages from the ecm. The one that stands out is pin F10 on the ecm has 5.2 volts coming from it with no wires connected to it. When I connect my vats bypass module it shows 2.7 V. This leads me to believe the injector control switch inside the ecm is not being properly enabled when the ignition is in start. This would normally be a VATS issue but since proper frequency is being sent to the VATS fuel enable wire on the ecm, it must be an internal fault which explains the output on fuel enable wire instead of it being just an input. also need to check a couple grounds from the ecm to ensure that is properly grounded as the resistance I found to be +1000 ohms on two of the four ecm grounds. A12 and D1 were 1000+ ohms and D6 and D7 were 15 ohms. A12 is most important because it is the ground to the entire ecm as apose to the other three they are just for the injectors to function. I don't believe ground is my issue tho because I ran jumpers directly to ground and it still didn't function but could have played a role in the ecm getting ruined. Why the car has started randomly three times total I have no idea.

tfitzy16

ECM was not bad. Bypass module was faulty. Verified this by ordering a new cheaper one on ebay from a different supplier. Connected same as old one and it fired right up every time I tried with no hesitation. Faulty one was from bakerelectronix.com who claimed they have never had one pass a volts output test done with a multimeter and still not start a car. Module is not outputting correct 30Hz signal my 7730 ecm requires on pin f10. Hope this helps someone else who tries to bypass VATS and has injector pulse issues after. now time to go to DMV and get behind the wheel.