Volvo: 1983 volvo 244 turbo gas, air control valve, volvo 244

Question
QUESTION: I have a Volvo that will be driving along and start jerking or on acceleration or at idle. Warm or cold makes no difference and as quickly as it has started it will stop and run fine. I have found the Air control valve disconnected so I reconnected no difference found a few vac hoses broken repaired them no difference. It is almost like a switch gets turned on then after a bit turned off. You can drive for a couple of days and it will be fine and then boom it starts at it and last 5-20+ mins. then just stop. It feels like if you don't give enough gas on the clutch and it does that jerky feeling. I was told by one person I need to start with changing the wiring harness that was done already. I did change the fuel filter. I am just frustrated at this point and I am not seeing the trees through the forest. Any help would be great. Thanks in advance.

ANSWER: Gina,
That car has two fuel pumps one under the car (main) and one in the tank (pre). I have seen where the in tank pump after a while running stops working or the fuel tank is too low on fuel and the hose to that pump is broken and can't pick up any fuel. That starves the main pump and you can get the hesitation. That would be a starting place.

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QUESTION: Sorry it has taken so long to respond back to you. I had to order the in take pump. I changed it and drove it for a day and a half and it was fine till I decided to drive one more time before calling my customer and sure enough when my road test was almost done it started to jerk. It cleared up before I was able to get back to the shop. I think I am just frustrated with this thing and my brain is cooked. Any other good thoughts you can throw my way. I am sure it is something totally stupid that is wrong with this and I am just over looking it. Well thanks for letting me vent. to

Answer
Gina,
Since it seemed as if the car was fixed and you are on the right track, there is a possibility that there is not enought fuel yet for the injectors. You might try a pre pump for a 940 turbo that one has more volumn and pressure. I have had to do that on a few occasions.