swap w/o ISV possible? engine is running like crud!
hey folks, read almost the entire thread, good stuff, hoping someone has some insight here.
I did a 16v 2.0 turbo install running Digi I from a Corrado. Almost everything is new, except the coil and 16v coolant temp sensor. The car starts and idles fine all day long, but boggs and bucks under load and sometimes when trying to hold revs in neutral.
the only major difference in install procedure is that I opted to not use the ISV. I'm in texas, we see 32deg F maybe two days out of the year (like tonight) so I don't mind warming the engine up a few min before leaving the house which is what I read people do when they do an ISV delete. Since the OBD2 throttlebody I'm using has no idle adjustment mechanism, I'm running a 1/8NPT bypass hose from the intake pipe just before the t-body to the intake manifold. I do have a ball valve inline but it seems to idle at a sweet 850-900 rpm with the valve fully open (so I prob don't need it, but it's there in case idle rises after being run a long time and I need to choke it a bit)
It's not turbo related, as I've disconnected the plumbing after the IC so it's basically like a N/A digi setup. The digi1 (corrado) co-pot aka. MAF is located 9" from the t-body and it ohms out good, set to 500.
gas goes form new fuel cell to new cis fuel pump to new inline filter to injector rail for 3.5bar fpr to return line/tank. I see a constant 48psi on my gauge at the end of the rail before the FPR during idle, but can't monitor it during driving. I'll try to rotate it and run w/o a hood or maybe install a pressure sensor/gauge later but I have no reason to believe it's starving for fuel. Running the pump to a bucket, it does surge which I know is bad for CIS but from what I read it's ok for Digi due to the lack of a diaphram/distributor.
And spark shows up nice when I use a timing light, and no arcing as i did a water mist test at night. again everything is new, brand new dist, cap, rotor, wires, plugs, o2, knock. Grounds are solid, running dual Optimas in the trunk and alt is putting out ~13.8. No vacuum leaks that I know of as I only have vacuum lines running to brake booster, ecu, fpr, boost gauge, and bov
I'm contemplating using the ISV, but I would rather not try to figure out how to custom fab it into the already diminishing space under the bonnet, so I'm hoping aomeone would have a say or other ideas to check.
ps. i also tried 2 diff chips in the ECU and the car performs the same using both a stock and stage4.