The 1993 Lada Niva – Part 8 Additional Repairs Continue!

A look back at our gone, but not forgotten, 1993 Lada Niva Project, originally published on 22 January 2013

The 1993 Lada Niva – Part 8 дополнительный ремонт (Additional Repairs)

Since we had the parts we moved onto the braking system, we had bled everything during the first round of work, but brake pedal effort remained high. No obvious leaks could be located so Shawn suspected the issue was in the master cylinder and vacuum booster assembly. Once we pulled the originals apart it, we were able to tell that the master was leaking at one fitting, and into the vacuum booster. The booster had a faulty diaphragm which provided no braking assist, and was feeding the engine a steady trickle of brake fluid. It didn’t help that the vacuum line going to the booster had a serious crack at the manifold fitting. So in reality we had no real power brake system to speak of

This was quickly remedied with the brand new parts from Ital Motors and some fresh brake fluid, followed by bleeding the air from the system and things were good to go. Now the Lada had a solid pedal that didn’t go soft when you needed to stop. The rear brakes were adjusted to specifications in the manual, and the job was complete.

Since we had some more time, things got a little more ambitious to inspect the source of a strong vacuum leak we had located near the carburetor. Although the Lada had been tested with a vacuum gauge and pulled a fairly steady 18 in-Hg at idle, the carb tended to surge and act a little funny from time to time. When tested with the shop Innovate LM-1 wideband meter, we observed wide open throttle ratios in the 12.5-12.8:1 range, mostly. The vacuum leak was located using the propane torch method and when all of the lines had been replaced, it left only the carb as suspect.

Off came the air cleaner and the carb followed, and what we seen next tells the story all on its own.

By the looks of it, the carb swap (whenever it had been done) was completed using the original gaskets which now had all the sealing capabilities of wadded newspaper. We removed all old gasket material, cleaned the intake manifold externally and reassembled everything with gasket paper and silicone.

This counted as the 12^th vacuum leak repaired, it was no small wonder that the carb was acting up all the time. After all this were rewarded with easier starting, smoother idle, and perfect wide open throttle air to fuel ratio of 13.3:1 and cruise at 14.7-15.1.