A bit more from the brain trust, Still need help with starting at the end of rustoration Options

[worn]

Hi folks. Ok, five years and the piles of parts have actually gone back onto the car. And, I er, ah tightened the head nuts to the proper torque. My problem is that it is hard to keep the motor running long enough to tune it. For example timing light.

The problem is that I want to adjust timing and fuel, but The motor isn’t running smooth enough to get there. The motor is a 2056 with the so-called Raby cam from WebCam. The MPS has been messed with, but it ran when parked. Took the motor out to split the case and address oil leaks. One thing led to another and the rust was replaced with yet to rust sheet metal, and paint etc.

I am looking for a starting condition that allows enough running to improve upon. Ideally, I would like the motor to idle somehow. I have a pretty big hint. If before start, with ign on I blip the throttle a few times, the fuel injectors click, and the motor will start, run and die. From this I think that the sparks are there and the injectors are capable of letting out enough gas to fire. The fuel pressure is constant 29 psi, and the injectors have been cleaned and tested. My problem is the MPS and ECU black boxes that govern fueling. I have an AFR gauge, but it would be more useful if the motor ran long enough to get a number to look at.

I am hoping for:
A magic bullet post that says something like clock the seatbelt bolts and it will start,

Or, basic starting adjustments for each thing that can be adjusted or tested. For example, I can static test the timing and measure MPS inductance vs vacuum. What else has to be in line? Head temp resistance value? Throttle TPS switch position or values? You folks comprise so much wisdom, so please let me get the car on the road now that spring is only months away!

[emerygt350]

I don't know Zach, the mps just isn't that sensitive. You can have it way off and the injectors will fire, just not much or too much.

If you want to test the mps, just pull the vacuum hose off of it. That will tell the ECU to go pig rich (wot).

If the cam were the problem we would have too much fuel due to low vacuum at idle.

I couldnt tell from your write up, but did you spin the dizzy with the key on out of the car? Just to see if the injectors are firing when the points tell them to?

Could be a wiring issue too, how old is the harness? Original?

ECU can't be excluded as the culprit at this point of course. Any extras laying around?

Did you do a leak down test on the mps? Check the resistance? And of course triple check the plugs wire order?

[worn]

I don't know Zach, the mps just isn't that sensitive. You can have it way off and the injectors will fire, just not much or too much.

If you want to test the mps, just pull the vacuum hose off of it. That will tell the ECU to go pig rich (wot).

If the cam were the problem we would have too much fuel due to low vacuum at idle.

I couldnt tell from your write up, but did you spin the dizzy with the key on out of the car? Just to see if the injectors are firing when the points tell them to?

Could be a wiring issue too, how old is the harness? Original?

ECU can't be excluded as the culprit at this point of course. Any extras laying around?

Did you do a leak down test on the mps? Check the resistance? And of course triple check the plugs wire order?

I have a spare MPS, calibrated acording to Brad Andfdrs excellent write up. That made no difference.
The cam ran well several years ago, for road and autocross. I put at least 5,000 miles on it.

I finally pulled out the injectors for #1 and #2. Asked them to squirt in a cup. No fuel coming out when cranking. Fuel pressure is at 29 psi, and the injectors spray perfectly when stimulated by a cheap little amazon injector driver. Nice tool incidentally.

Pulled the trigger points and they look fine and function on the bench. However, just to be sure I connected another dizzy to the trigger connector and spun the rotor with the ignition on. That produced no response from either injector, but it did cause the fuel pump to go on and off as I turned the shaft. THat has me puzzled because I cannot trace the wiring for that.

I tested the resistance of the head temp sensor and it was 3-4 kilo Ohms, and I also substituted a new sensor with no success.

Finally, I have messed with the harness. I put new connectors and boots on the engine harness. In addition, I disassembled the block that plugs into the relay board to get the wires through the snorkel. With those caveats in mind, I was very careful, and the motor has run for several minutes, but would not restart after warming. Now it doesn't seem to want to start at all.

I have a couple of old ECUs that I can try, but that has seemed a long shot toi me so I haven't. Anything else before I try that? I hate to strain the boards with that big plug.

Thanks again!

[emerygt350]

I don't know Zach, the mps just isn't that sensitive. You can have it way off and the injectors will fire, just not much or too much.

If you want to test the mps, just pull the vacuum hose off of it. That will tell the ECU to go pig rich (wot).

If the cam were the problem we would have too much fuel due to low vacuum at idle.

I couldnt tell from your write up, but did you spin the dizzy with the key on out of the car? Just to see if the injectors are firing when the points tell them to?

Could be a wiring issue too, how old is the harness? Original?

ECU can't be excluded as the culprit at this point of course. Any extras laying around?

Did you do a leak down test on the mps? Check the resistance? And of course triple check the plugs wire order?

I have a spare MPS, calibrated acording to Brad Andfdrs excellent write up. That made no difference.
The cam ran well several years ago, for road and autocross. I put at least 5,000 miles on it.

I finally pulled out the injectors for #1 and #2. Asked them to squirt in a cup. No fuel coming out when cranking. Fuel pressure is at 29 psi, and the injectors spray perfectly when stimulated by a cheap little amazon injector driver. Nice tool incidentally.

Pulled the trigger points and they look fine and function on the bench. However, just to be sure I connected another dizzy to the trigger connector and spun the rotor with the ignition on. That produced no response from either injector, but it did cause the fuel pump to go on and off as I turned the shaft. THat has me puzzled because I cannot trace the wiring for that.

I tested the resistance of the head temp sensor and it was 3-4 kilo Ohms, and I also substituted a new sensor with no success.

Finally, I have messed with the harness. I put new connectors and boots on the engine harness. In addition, I disassembled the block that plugs into the relay board to get the wires through the snorkel. With those caveats in mind, I was very careful, and the motor has run for several minutes, but would not restart after warming. Now it doesn't seem to want to start at all.

I have a couple of old ECUs that I can try, but that has seemed a long shot toi me so I haven't. Anything else before I try that? I hate to strain the boards with that big plug.

Thanks again!

wow, that really does make me wonder about the ECU. It really isn't bad to unplug so if you have extras I would give it a go, easy, quick. And do a quick leakdown test on that mps just in case.


what year is the car/ecu?

have you tried running it with the tps disconnected?