My 1988 Alfa 75 3.0 V6 seems to be bogging under acceleration. After reaching operating temperature, it can run fine for a few minutes (plenty of power), but then it frequently has a few bad minutes where it has no power, jerks and hesitates with acceleration and sometimes backfires with a pop. It s…

Yeah, I saw it But I’m not yet 100% convinced the fuel pump . . . which OP replaced with a new Bosch unit, apparently . . . is the cause and not the symptom

Ok. I missed the ‘replaced the fuel pump’ step…still reading that other thread :grin:

There might be a slurry of rust particles in the bottom of the tank plugging the inlet screen. If the inlet screen has fallen apart the contaminants will enter the fuel pump. Remove the inlet line from the fuel pump, capture the fuel from the line and inspect for rust.

On my Rabbit’s K-Jetronic CIS system I’d have to manually pull that vane upwards to get the fuel to flow to the injectors for testing purposes. I’m surprised a 1988 vehicle would still use that vane technique. The way the K version meters out the fuel in correct proportion to the airflow is that …

[image] db4690: You have no idea what OP’s fuel pressures are supposed to be, unless you’re somehow holding out on us? And you said the numbers he provided sounded okay, because your car is of similar vintage If that’s not guessing, what is? No disagreement, I have no experience with the Bo…

The MAF is still electronic; as air passes through the sort of butterfly valve, the valve opens (more with more airflow) which in turn rotates an electronic switch. Thanks for your replies. I’ll run some tests and check for blockages some time next week.

I had some really difficult to diagnose problems on my K-Jetronic with the fuel pump relay. If I had those symptoms you have on an L-Jetronic, without any other ideas, that’d be my first suspect. Replacing the fuel pump relay btw didn’t fix the problem, b/c the problem wasn’t the relay itself, it…

Back again. Issue still not solved. Any ideas would be appreciated Current Issue: Loud whining fuel pump (brand new), and engine bogging on acceleration after about 10 minutes of light driving. Recent Work Done: Suspected a blockage in the fuel tank, so we began to drain it from the main outlet (…

I don’t recall, have you removed and cleaned / replaced the fuel tank yet? Given the trajectory you are on, that is looking like a job that will soon be in your future. The jet-tronic injection system is very unforgiving of grit in the gas supply. You new fuel pump may be clogged w/grit too btw. …

I think the new fuel filter is too small (not enough flow). I’ll replace that first

Alfa 75 3.0 V6 Bogging on Acceleration & Slow to Start

Maintenance/Repairs

jackocooper March 7, 2018, 3:30pm 71

Passed the MOT first time, running great. Now onto the paint! Any advice would be appreciated! Restoring red paint, tcut?

Topic		Replies	Views
Spluttering/ Misfiring, Loss of Power, Cutout at Idle Maintenance/Repairs engines , alfaromeo	4	859	August 31, 2017
Fuel system issues, old mechanical type and Qjet Maintenance/Repairs oldsmobile , cutlass	43	10554	July 14, 2018
Getting harder to start Maintenance/Repairs	26	4412	July 12, 2009
Cold Engine Start and Stall+Cold Engine Loss of Acceleration Maintenance/Repairs nissan , sentra	30	19477	May 27, 2018
Car runs poorly after being left to cool for 20 minutes Maintenance/Repairs alfaromeo	12	919	April 23, 2018

Alfa 75 3.0 V6 Bogging on Acceleration & Slow to Start

Related topics