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Update: I finally got my fuel pressure gauge installed with no leaks (I made a mistake and didn't use any permatex on the threads so it sprayed gas) fuel pressure is around 40psi on idle and when I gave it a little throttle it jumped up to 60psi so I think it's safe to assume that the fuel system and FMU are functioning. I still have a code 34 which has the car running terribly and I inspected all the Maf wires and they all seem to be perfect. I am replacing both MAF relays today.
I do see that the previous owner has a Duralast MAF on it (I have had terrible luck with Duralast sensors on every car I have owned) so I will be throwing a new Delphi MAF on the car to see if this corrects this lean issue.
I have to order a new cable to view live data on the car as I forgot that I left the cable I had in my 92 when I sold it.
The FMU needs to be adjusted down. It should only increase fuel pressure under boost, not just when you give it a little throttle. Tunercat sells a cable that works with their software datacat.
Say no to Delphi unless you want to add more problems to the list. Many reports of rich idle and minimum voltage output around 800 mv or ~9.5 gm/sec. I wouldn't trust the calibration if they can't even get the idle airflow right.
That sounds right, I was playing with the FMU to see if it helped with the lean condition and under throttle the wide and went down to 11:5 but idles lean still, I threw the new MAF power and burn-off relays on today and I cleaned the MAF and I was mistaken, the previous owner threw a Walker brand on the car which does not support the burn off function and I’ve been seeing terrible reviews.
If Delphi is a no go would you recommend a Bosch instead?
In regards to the engine build, I was going through the receipts I was given and the shop the guy has the motor built at has a description of everything but nothing on the rotating assembly, I called them and they said their system crashed last year and lost all records so I am going to assume that the motor is not forged, although I am pretty sure the rings were gapped for boost as it is mentioned.
Also here’s a picture of the car, the Enkei wheels will be going soon and I’m going to throw some C5 Z06’s on it.
Last edited by Clarkerusty; Jun 15, 2024 at 11:03 PM.
If it mentions gapping the rings for boost then you would hope they used forged pistons. I would pull a plug and slip a borescope in to get the numbers off the top of a piston. Then you can look them up to verify.
Thank you for that advice, I will order a borescope to take a look asap.
I may start another thread on this subject but is anyone here familiar with Fitech's standalone TPI harness?
Although I would be ditching the CARB legal aspect of this build (I have a "workaround" for keeping the car California legal in this case) but as this standalone system supports timing control, boost control and fueling while only costing a couple hundred more than an MSD BTM I am taking this into consideration so any feedback on this would be awesome.
Update: Although it was advised against I installed a new Delphi MAF on the car and that fixed my lean condition, the car idles around 14:5 and drops to 11:5-12:3 when accelerating so now it's time for my MSD BTM.
Are you guys using the factory HEI large cap with the adapter from MSD or are you guys using an aftermarket Dizzy?
As a precautionary measure I did another compression test on the car (all at 175psi on the dot) and I noticed that two of the plugs are cracked and they are some NGKs that are gapped at .035 and in the heat range 6
Before I order the new plugs I’d like to get some insight on which plugs have done well for others, @MrBigDee recommended the Accels and I may end up going with those.
I do know the gap should be closed closer to 0.25 but what heat range should I aim for?
Thank you for that table, I ordered the 0414’s from Accel and my BTM will arrive on Tuesday.
just out of curiosity as I’m unsure of how the ECMs work but if the O2 sensors detect too much fuel in the exhaust will it lean out the system?
In closed loop the program bounces the afr rich lean rapidly. This is for smog-for operation of the cat convertor. It averages it to stioch=14.7:1.When you go into PE (power enrich) under heavier throttle and when cold on start up then it is open loop and stays at a programmed afr.
Do your self a favor and upgrade your ECU to something like terminator x. Then get it tuned. Until then, it’s all trial and error.
The problem is he is in Kali and trying to keep it smoggable to avoid hassles. I have not found any aftermarket ECM (other than EBL) that can run EGR, CCP, and Air.
The problem is he is in Kali and trying to keep it smoggable to avoid hassles. I have not found any aftermarket ECM (other than EBL) that can run EGR, CCP, and Air.
^^^I would love to just throw a Terminator or a Fitech on the car but keeping the car smog legal makes that option a no go.
